Saquinavir

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product

Capsule, Oral:

Invirase: 200 mg [DSC]

Tablet, Oral:

Invirase: 500 mg

Pharmacology

Mechanism of Action

Binds to the site of HIV-1 protease activity and inhibits cleavage of viral Gag-Pol polyprotein precursors into individual functional proteins required for infectious HIV. This results in the formation of immature, noninfectious viral particles.

Pharmacokinetics/Pharmacodynamics

Absorption

Poor; increased with high-fat meal

Distribution

V_d: 700 L; does not distribute into CSF; partitions into tissues

Metabolism

Extensively hepatic via CYP3A4 to inactive mono- and dihydroxylated metabolites; extensive first-pass effect

Excretion

Feces (81% to 88%), urine (1% to 3%) within 5 days

Clearance: Children: Significantly higher than adults

Half-Life Elimination

Serum: 1 to 2 hours

Protein Binding

Plasma: ~98%

Use in Specific Populations

Special Populations: Hepatic Function Impairment

Approximately 30% reduction in saquinavir exposure in patients with moderate hepatic impairment.

Use: Labeled Indications

HIV-1 infection: Treatment of HIV-1 infection in adults (>16 years) in combination with ritonavir and other antiretroviral agents

Contraindications

Hypersensitivity (eg, anaphylactic reaction, Stevens-Johnson syndrome) to saquinavir, saquinavir mesylate, or any component of the formulation; congenital QT prolongation, refractory hypokalemia or hypomagnesemia, concomitant use of other medications that both increase saquinavir plasma concentrations and prolong the QT interval; complete AV block (without implanted ventricular pacemaker) or patients at high risk of complete AV block; severe hepatic impairment; coadministration of saquinavir/ritonavir with CYP3A substrates (eg, alfuzosin, amiodarone, atazanavir, bepridil, chlorpromazine, cisapride, clarithromycin, clozapine, dasatinib, disopyramide, dofetilide, ergot derivatives [dihydroergotamine, ergonovine, ergotamine, methylergonovine], erythromycin, flecainide, halofantrine, haloperidol, lidocaine [systemic], lovastatin, lurasidone, midazolam [oral], pentamidine, phenothiazines, pimozide, propafenone, quinidine, quinine, rifampin, rilpivirine [concomitant use or when switching to saquinavir/ritonavir without a ≥2-week washout period], sertindole, sildenafil [when used for pulmonary artery hypertension {eg, Revatio}], simvastatin, sunitinib, tacrolimus, thioridazine, trazodone, triazolam, ziprasidone).

Canadian labeling: Additional contraindications (not in US labeling): Concurrent use with quetiapine, procainamide, sotalol, astemizole, or terfenadine; concurrent use with medications that both increase saquinavir plasma concentrations and prolong the PR interval; acquired QT prolongation

Dosage and Administration

Dosing: Adult

Note: Invirase 200 mg capsules have been discontinued in the United States for more than 1 year.

Note: ECG should be done prior to starting therapy; do not initiate therapy if pretreatment QT interval ≥450 msec. Saquinavir should always be used with concomitant ritonavir; cobicistat is not interchangeable with ritonavir to increase systemic exposure.

HIV-1 infection, treatment: Oral: Usual dosage: 1,000 mg twice daily given in combination with ritonavir 100 mg twice daily. For patients already taking ritonavir 100 mg twice daily as part of their antiretroviral regimen, no additional ritonavir is needed.

Treatment-naive patients or patients switching from a regimen containing delavirdine. Note: Patients with recent exposure (without washout) to a ritonavir or non-nucleoside reverse transcriptase inhibitor based regimen (not including delavirdine or rilpivirine) may receive usual initial dosing (ie, saquinavir 1,000 mg twice daily in combination with ritonavir 100 mg twice daily).

Initial: Saquinavir 500 mg twice daily given in combination with ritonavir 100 mg twice daily for 7 days.

Maintenance: Saquinavir 1,000 mg twice daily given in combination with ritonavir 100 mg twice daily.

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Note: Invirase 200 mg capsules have been discontinued in the US for >1 year.

Note: ECG should be done prior to starting therapy; do not initiate therapy if pretreatment QT interval >450 msec or if there is a diagnosis of long QT syndrome. Saquinavir must only be used in regimens that include ritonavir "booster doses" so that adequate saquinavir serum concentrations are attained; do not use without ritonavir booster doses.

HIV-1 Infection, treatment: Use in combination with other antiretroviral agents.

Infants and Children <2 years: Not approved for use; appropriate dose is unknown.

Children ≥2 years and Adolescents <16 years: Treatment-experienced, ritonavir-boosted regimen: Limited data available (HHS [pediatric] 2016): Oral:

5 kg to <15 kg: Saquinavir 50 mg/kg/dose twice daily plus ritonavir 3 mg/kg/dose twice daily

15 kg to <40 kg: Saquinavir 50 mg/kg/dose (maximum dose: 1,000 mg/dose) twice daily plus ritonavir 2.5 mg/kg/dose twice daily

≥40 kg: Saquinavir 1000 mg plus ritonavir 100 mg twice daily

Adolescents ≥16 years: Limited data available for adolescents 16 years of age (HHS [pediatric] 2016): Oral: 1,000 mg twice daily given in combination with ritonavir 100 mg twice daily. For patients already taking ritonavir 100 mg twice daily as part of their antiretroviral regimen, no additional ritonavir is needed.

Treatment-naive patients or patients switching from a regimen containing delavirdine or rilpivirine: Adolescents >16 years: Note: Patients with recent exposure (without washout) to a ritonavir or non-nucleoside reverse transcriptase inhibitor-based regimen (not including delavirdine or rilpivirine) may receive usual initial dosing (ie, saquinavir 1,000 mg twice daily in combination with ritonavir 100 mg twice daily).

Initial: Saquinavir 500 mg twice daily given in combination with ritonavir 100 mg twice daily for 7 days

Maintenance: Saquinavir 1,000 mg twice daily given in combination with ritonavir 100 mg twice daily

Administration

Oral: Administer saquinavir and ritonavir at the same time and within 2 hours after a full meal. Patients unable to swallow capsules may open capsules and mix contents with 15 mL of syrup (or sorbitol if diabetic or glucose intolerant) or with 3 teaspoons of jam. Mixture should be stirred for 30 to 60 seconds and then administered entirely. Suspension should be at room temperature prior to administration. Do not crush tablets.

Dietary Considerations

Take within 2 hours after a meal. Product contains lactose.

Storage

Store at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F).

Drug Interactions

Abacavir: Protease Inhibitors may decrease the serum concentration of Abacavir. Monitor therapy

Abemaciclib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Abemaciclib. Management: In patients taking abemaciclib at a dose of 200 mg or 150 mg twice daily, reduce the dose to 100 mg twice daily when combined with strong CYP3A4 inhibitors. In patients taking abemaciclib 100 mg twice daily, decrease the dose to 50 mg twice daily. Consider therapy modification

Acalabrutinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Acalabrutinib. Avoid combination

Ado-Trastuzumab Emtansine: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Ado-Trastuzumab Emtansine. Specifically, strong CYP3A4 inhibitors may increase concentrations of the cytotoxic DM1 component. Avoid combination

Afatinib: Saquinavir may increase the serum concentration of Afatinib. Management: Per US labeling: reduce afatinib by 10 mg if not tolerated. Per Canadian labeling: avoid combination if possible; if used, administer saquinavir simultaneously with or after the dose of afatinib. Consider therapy modification

Alfuzosin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Alfuzosin. Avoid combination

Alfuzosin: Protease Inhibitors may increase the serum concentration of Alfuzosin. Avoid combination

Alitretinoin (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Alitretinoin (Systemic). Management: Consider reducing the alitretinoin dose to 10 mg when used together with strong CYP3A4 inhibitors. Monitor for increased alitretinoin effects/toxicities if combined with a strong CYP3A4 inhibitor. Consider therapy modification

Almotriptan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Almotriptan. Management: Limit initial almotriptan adult dose to 6.25 mg and maximum adult dose to 12.5 mg/24-hrs when used with a strong CYP3A4 inhibitor. Avoid concurrent use in patients with impaired hepatic or renal function. Consider therapy modification

Alosetron: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Alosetron. Monitor therapy

ALPRAZolam: CYP3A4 Inhibitors (Strong) may increase the serum concentration of ALPRAZolam. Management: Consider using an alternative agent that is less likely to interact. If combined, monitor for increased therapeutic/toxic effects of alprazolam if combined with a strong CYP3A4 inhibitor. Consider therapy modification

Amiodarone: Saquinavir may enhance the QTc-prolonging effect of Amiodarone. Saquinavir may increase the serum concentration of Amiodarone. Avoid combination

AmLODIPine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of AmLODIPine. Monitor therapy

Antidiabetic Agents: Hyperglycemia-Associated Agents may diminish the therapeutic effect of Antidiabetic Agents. Monitor therapy

Antipsychotic Agents (Phenothiazines): May enhance the arrhythmogenic effect of Saquinavir. Management: Drugs listed as exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Exceptions: ChlorproMAZINE. Avoid combination

Apixaban: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Apixaban. Monitor therapy

Aprepitant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Aprepitant. Avoid combination

ARIPiprazole: CYP3A4 Inhibitors (Strong) may increase the serum concentration of ARIPiprazole. Management: See full interaction monograph for details. Consider therapy modification

ARIPiprazole Lauroxil: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of ARIPiprazole Lauroxil. Management: Please refer to the full interaction monograph for details concerning the recommended dose adjustments. Consider therapy modification

Astemizole: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Astemizole. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Astemizole. Avoid combination

Asunaprevir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Asunaprevir. Avoid combination

Atazanavir: Saquinavir may increase the serum concentration of Atazanavir. Atazanavir may increase the serum concentration of Saquinavir. Avoid combination

AtorvaSTATin: Protease Inhibitors may increase the serum concentration of AtorvaSTATin. Management: See full monograph for recommended dose limits. Avoid atorvastatin with tipranavir/ritonavir. Consider therapy modification

Avanafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Avanafil. Avoid combination

Avapritinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Avapritinib. Avoid combination

Axitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Axitinib. Management: Avoid concurrent use of axitinib with any strong CYP3A inhibitor whenever possible. If a strong CYP3A inhibitor must be used with axitinib, a 50% axitinib dose reduction is recommended. Consider therapy modification

Barnidipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Barnidipine. Avoid combination

Bedaquiline: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Bedaquiline. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Bedaquiline. Management: Consider alternatives to this drug combination and avoid use for more than 14 days. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk. Consider therapy modification

Benperidol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Benperidol. Monitor therapy

Benzhydrocodone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Benzhydrocodone. Specifically, the concentration of hydrocodone may be increased. Monitor therapy

Betamethasone (Ophthalmic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Betamethasone (Ophthalmic). Monitor therapy

Bictegravir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Bictegravir. Monitor therapy

Bitter Orange: May increase the serum concentration of Saquinavir. Monitor therapy

Blonanserin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Blonanserin. Avoid combination

Bortezomib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Bortezomib. Monitor therapy

Bosentan: May decrease the serum concentration of Saquinavir. Saquinavir may increase the serum concentration of Bosentan. Management: Use bosentan 62.5 mg/day or every other day in adult patients taking saquinavir/ritonavir for at least 10 days. Temporarily stop bosentan (for at least 36 hrs) before starting saquinavir/ritonavir; wait at least 10 days before restarting bosentan. Consider therapy modification

Bosutinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Bosutinib. Avoid combination

Brentuximab Vedotin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Brentuximab Vedotin. Specifically, concentrations of the active monomethyl auristatin E (MMAE) component may be increased. Monitor therapy

Brexpiprazole: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Brexpiprazole. Management: Reduce brexpiprazole dose 50% with strong CYP3A4 inhibitors; reduce to 25% of usual if used with both a moderate CYP3A4 inhibitor and a CYP2D6 inhibitor in patients not being treated for MDD, or strong CYP3A4 inhibitor used in a CYP2D6 poor metabolizer. Consider therapy modification

Brigatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Brigatinib. Management: Avoid concurrent use of brigatinib with strong CYP3A4 inhibitors when possible. If combination cannot be avoided, reduce the brigatinib dose by approximately 50%, rounding to the nearest tablet strength (ie, from 180 mg to 90 mg, or from 90 mg to 60 mg). Consider therapy modification

Brinzolamide: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Brinzolamide. Monitor therapy

Bromocriptine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Bromocriptine. Avoid combination

Budesonide (Nasal): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Budesonide (Nasal). Monitor therapy

Budesonide (Oral Inhalation): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Budesonide (Oral Inhalation). Monitor therapy

Budesonide (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Budesonide (Systemic). Avoid combination

Budesonide (Topical): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Budesonide (Topical). Management: Per US prescribing information, avoid this combination. Canadian product labeling does not recommend strict avoidance. If combined, monitor for excessive glucocorticoid effects as budesonide exposure may be increased. Consider therapy modification

Buprenorphine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Buprenorphine. Monitor therapy

BusPIRone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of BusPIRone. Management: Limit the buspirone dose to 2.5 mg daily and monitor patients for increased buspirone effects/toxicities if combined with strong CYP3A4 inhibitors. Consider therapy modification

Cabazitaxel: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cabazitaxel. Management: Concurrent use of cabazitaxel with strong inhibitors of CYP3A4 should be avoided when possible. If such a combination must be used, consider a 25% reduction in the cabazitaxel dose. Consider therapy modification

Cabozantinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cabozantinib. Management: Avoid use of a strong CYP3A4 inhibitor with cabozantinib if possible. If combined, cabozantinib dose adjustments are recommended and vary based on the cabozantinib product used and the indication for use. See monograph for details. Consider therapy modification

Calcifediol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Calcifediol. Monitor therapy

Calcium Channel Blockers (Nondihydropyridine): Protease Inhibitors may decrease the metabolism of Calcium Channel Blockers (Nondihydropyridine). Increased serum concentrations of the calcium channel blocker may increase risk of AV nodal blockade. Management: Avoid concurrent use when possible. If used, monitor for CCB toxicity. The manufacturer of atazanavir recommends a 50% dose reduction for diltiazem be considered. Saquinavir, tipranavir, and darunavir/cobicistat use with bepridil is contraindicated. Consider therapy modification

Cannabidiol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cannabidiol. Monitor therapy

Cannabis: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cannabis. More specifically, tetrahydrocannabinol and cannabidiol serum concentrations may be increased. Monitor therapy

CarBAMazepine: May increase the metabolism of Protease Inhibitors. Protease Inhibitors may decrease the metabolism of CarBAMazepine. Consider therapy modification

Cariprazine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cariprazine. Management: Cariprazine dose reductions of 50% are required; specific recommended management varies slightly for those stable on cariprazine versus those just starting cariprazine. See prescribing information or full interaction monograph for details. Consider therapy modification

Cat's Claw: May increase the serum concentration of Saquinavir. Monitor therapy

Ceritinib: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Ceritinib. Management: Avoid concomitant use of ceritinib and strong CYP3A4 inhibitors that prolong the QTc interval whenever possible. If combined, decrease ceritinib dose by one-third and monitor patients for ceritinib toxicities including QTc prolongation and arrhythmias. Consider therapy modification

Cilostazol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cilostazol. Management: Consider reducing the cilostazol dose to 50 mg twice daily in adult patients who are also receiving strong inhibitors of CYP3A4. Consider therapy modification

Cinacalcet: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cinacalcet. Monitor therapy

Cisapride: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Cisapride. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Cisapride. Avoid combination

Citalopram: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Citalopram. Monitor therapy

Clarithromycin: Saquinavir may enhance the QTc-prolonging effect of Clarithromycin. Clarithromycin may increase the serum concentration of Saquinavir. Avoid combination

Clorazepate: Saquinavir may increase the serum concentration of Clorazepate. Monitor therapy

CloZAPine: Saquinavir may enhance the QTc-prolonging effect of CloZAPine. Avoid combination

Cobicistat: May increase the serum concentration of Saquinavir. However, the magnitude of this change is unclear, and dosing recommendations for this combination are not available. Avoid combination

Cobimetinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cobimetinib. Avoid combination

Codeine: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Codeine. Monitor therapy

Colchicine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Colchicine. Management: Colchicine is contraindicated in patients with impaired renal or hepatic function who are also receiving a strong CYP3A4 inhibitor. In those with normal renal and hepatic function, reduce colchicine dose as directed. See full monograph for details. Consider therapy modification

Conivaptan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Conivaptan. Avoid combination

Copanlisib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Copanlisib. Management: If concomitant use of copanlisib and strong CYP3A4 inhibitors cannot be avoided, reduce the copanlisib dose to 45 mg. Monitor patients for increased copanlisib effects/toxicities. Consider therapy modification

Corticosteroids (Orally Inhaled): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Corticosteroids (Orally Inhaled). Management: Orally inhaled fluticasone propionate with a strong CYP3A4 inhibitor is not recommended. Exceptions: Beclomethasone (Oral Inhalation); Triamcinolone (Systemic). Monitor therapy

Corticosteroids (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Corticosteroids (Systemic). Exceptions: MethylPREDNISolone; PrednisoLONE (Systemic); PredniSONE. Monitor therapy

Crizotinib: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Crizotinib. Management: Avoid concomitant use of crizotinib and strong CYP3A4 inhibitors that prolong the QTc interval whenever possible. If combined, decrease crizotinib dose to 250 mg daily. Monitor patients for crizotinib toxicities including QTc prolongation and arrhythmias. Consider therapy modification

Cyclophosphamide: Protease Inhibitors may enhance the adverse/toxic effect of Cyclophosphamide. Specifically, the incidences of neutropenia, infection, and mucositis may be increased. Monitor therapy

CycloSPORINE (Systemic): Protease Inhibitors may increase the serum concentration of CycloSPORINE (Systemic). CycloSPORINE (Systemic) may increase the serum concentration of Protease Inhibitors. Consider therapy modification

CycloSPORINE (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of CycloSPORINE (Systemic). Consider therapy modification

CYP3A4 Inducers (Moderate): May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

CYP3A4 Inducers (Strong): May increase the metabolism of CYP3A4 Substrates (High risk with Inducers). Management: Consider an alternative for one of the interacting drugs. Some combinations may be specifically contraindicated. Consult appropriate manufacturer labeling. Consider therapy modification

CYP3A4 Substrates (High risk with Inhibitors): CYP3A4 Inhibitors (Strong) may decrease the metabolism of CYP3A4 Substrates (High risk with Inhibitors). Exceptions: Alitretinoin (Systemic); AmLODIPine; Benzhydrocodone; Buprenorphine; Gefitinib; HYDROcodone; Mirtazapine; Praziquantel; Telithromycin; Vinorelbine. Consider therapy modification

Dabrafenib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dabrafenib. Avoid combination

Daclatasvir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Daclatasvir. Management: Decrease the daclatasvir dose to 30 mg once daily if combined with a strong CYP3A4 inhibitor. No dose adjustment is needed when daclatasvir is used with darunavir/cobicistat. Consider therapy modification

Dapoxetine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dapoxetine. Avoid combination

Darunavir: Saquinavir may decrease the serum concentration of Darunavir. Avoid combination

Dasatinib: May enhance the QTc-prolonging effect of Saquinavir. Saquinavir may increase the serum concentration of Dasatinib. Avoid combination

Deferasirox: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

Deflazacort: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Deflazacort. Management: Administer one third of the recommended deflazacort dose when used together with a strong or moderate CYP3A4 inhibitor. Consider therapy modification

Delamanid: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Delamanid. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Delamanid. Management: If coadministration of delamanid with any strong CYP3A4 inhibitor is considered necessary, very frequent monitoring of ECGs is recommended throughout the full delamanid treatment period. Consider therapy modification

Delavirdine: Protease Inhibitors may decrease the serum concentration of Delavirdine. Delavirdine may increase the serum concentration of Protease Inhibitors. Consider therapy modification

DexAMETHasone (Ophthalmic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of DexAMETHasone (Ophthalmic). Monitor therapy

DiazePAM: Saquinavir may increase the serum concentration of DiazePAM. Monitor therapy

Disopyramide: Saquinavir may enhance the QTc-prolonging effect of Disopyramide. Saquinavir may increase the serum concentration of Disopyramide. Avoid combination

DOCEtaxel: CYP3A4 Inhibitors (Strong) may increase the serum concentration of DOCEtaxel. Management: Avoid the concomitant use of docetaxel and strong CYP3A4 inhibitors when possible. If combined use is unavoidable, consider a 50% docetaxel dose reduction and monitor for increased docetaxel toxicities. Consider therapy modification

Domperidone: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Domperidone. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Domperidone. Avoid combination

Doxercalciferol: CYP3A4 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Doxercalciferol. Monitor therapy

DOXOrubicin (Conventional): CYP3A4 Inhibitors (Strong) may increase the serum concentration of DOXOrubicin (Conventional). Management: Seek alternatives to strong CYP3A4 inhibitors in patients treated with doxorubicin whenever possible. One U.S. manufacturer (Pfizer Inc.) recommends that these combinations be avoided. Consider therapy modification

Dronabinol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dronabinol. Monitor therapy

Dronedarone: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Dronedarone. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Dronedarone. Avoid combination

Drospirenone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Drospirenone. Management: Drospirenone use is contraindicated specifically when the strong CYP3A4 inhibitors atazanavir and cobicistat are administered concurrently. Caution should be used when drospirenone is coadministered with other strong CYP3A4 inhibitors. Consider therapy modification

Dutasteride: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dutasteride. Monitor therapy

Duvelisib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Duvelisib. Management: Reduce the dose of duvelisib to 15 mg twice a day when used together with a strong CYP3A4 inhibitor. Consider therapy modification

Efavirenz: Saquinavir may enhance the adverse/toxic effect of Efavirenz. Efavirenz may decrease the serum concentration of Saquinavir. Management: When used together with efavirenz, saquinavir should not be used as the sole protease inhibitor. Appropriate doses of the combination of efavirenz with saquinavir/ritonavir have not been established. Consider therapy modification

Elagolix: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Elagolix. Management: Use of the elagolix 200 mg twice daily dose with a strong CYP3A4 inhibitor for longer than 1 month is not recommended. Limit combined use of the elagolix 150 mg once daily dose with a strong CYP3A4 inhibitor to a maximum of 6 months. Consider therapy modification

Eletriptan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Eletriptan. Avoid combination

Elexacaftor, Tezacaftor, and Ivacaftor: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Elexacaftor, Tezacaftor, and Ivacaftor. Management: When combined with strong CYP3A4 inhibitors, administer two elexacaftor/tezacaftor/ivacaftor tablets (100 mg/50 mg/75 mg) in the morning, twice a week, approximately 3 to 4 days apart. No evening doses of ivacaftor (150 mg) alone should be administered. Consider therapy modification

Eliglustat: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Eliglustat. Management: Use should be avoided under some circumstances. See full drug interaction monograph for details. Consider therapy modification

Eluxadoline: Saquinavir may increase the serum concentration of Eluxadoline. Management: Decrease the eluxadoline dose to 75 mg twice daily if combined with saquinavir and monitor patients for increased eluxadoline effects/toxicities. Consider therapy modification

Encorafenib: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Encorafenib. Management: Avoid using strong CYP3A4 inhibitors together with encorafenib if possible. If the combination must be used, reduce the encorafenib dose and monitor QT interval. See monograph for details. Consider therapy modification

Enfortumab Vedotin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Enfortumab Vedotin. Specifically, concentrations of the active monomethyl auristatin E (MMAE) component may be increased. Monitor therapy

Enfuvirtide: Protease Inhibitors may increase the serum concentration of Enfuvirtide. Enfuvirtide may increase the serum concentration of Protease Inhibitors. Monitor therapy

Entrectinib: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Entrectinib. Avoid combination

Enzalutamide: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Concurrent use of enzalutamide with CYP3A4 substrates that have a narrow therapeutic index should be avoided. Use of enzalutamide and any other CYP3A4 substrate should be performed with caution and close monitoring. Consider therapy modification

Eplerenone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Eplerenone. Avoid combination

Erdafitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Erdafitinib. Management: Avoid concomitant use of erdafitinib and strong CYP3A4 inhibitors when possible. If combined, monitor closely for erdafitinib adverse reactions and consider dose modifications accordingly. Consider therapy modification

Ergot Derivatives: Protease Inhibitors may increase the serum concentration of Ergot Derivatives. Exceptions: Cabergoline; Nicergoline; Pergolide. Avoid combination

Erlotinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Erlotinib. Management: Avoid use of this combination when possible. When the combination must be used, monitor the patient closely for the development of severe adverse reactions, and if such severe reactions occur, reduce the erlotinib dose (in 50 mg decrements). Consider therapy modification

Erythromycin (Systemic): May enhance the QTc-prolonging effect of Saquinavir. Erythromycin (Systemic) may increase the serum concentration of Saquinavir. Avoid combination

Estrogen Derivatives: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Estrogen Derivatives. Monitor therapy

Estrogen Derivatives (Contraceptive): Protease Inhibitors may decrease the serum concentration of Estrogen Derivatives (Contraceptive). Management: Use oral contraceptives containing at least 35mcg ethinyl estradiol with atazanavir/ritonavir, or no more than 30mcg in patients receiving atazanavir alone. Use of an alternative, non-hormonal contraceptive is recommended with other protease inhibitors. Consider therapy modification

Eszopiclone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Eszopiclone. Management: Limit the eszopiclone dose to 2 mg daily when combined with strong CYP3A4 inhibitors and monitor for increased eszopiclone effects and toxicities (eg, somnolence, drowsiness, CNS depression). Consider therapy modification

Etizolam: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Etizolam. Management: Consider use of lower etizolam doses when using this combination; specific recommendations concerning dose adjustment are not available. Monitor clinical response to the combination closely. Consider therapy modification

Etravirine: Protease Inhibitors may decrease the serum concentration of Etravirine. This effect is anticipated with darunavir, saquinavir, and lopinavir (with low-dose ritonavir). Etravirine may increase the serum concentration of Protease Inhibitors. This effect is anticipated with nelfinavir. Management: Low-dose ritonavir boosting must be used when any protease inhibitor is used with etravirine. Avoid use of etravirine in combination with atazanavir, fosamprenavir, full-dose ritonavir (600 mg twice daily, in adults), or tipranavir. Monitor therapy

Everolimus: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Everolimus. Avoid combination

Evogliptin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Evogliptin. Monitor therapy

Fedratinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Fedratinib. Management: Consider alternatives when possible. If used together, decrease fedratinib dose to 200 mg/day. After the inhibitor is stopped, increase fedratinib to 300 mg/day for the first 2 weeks and then to 400 mg/day as tolerated. Consider therapy modification

FentaNYL: CYP3A4 Inhibitors (Strong) may increase the serum concentration of FentaNYL. Management: Monitor patients closely for several days following initiation of this combination, and adjust fentanyl dose as necessary. Consider therapy modification

Fesoterodine: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Fesoterodine. Management: Avoid fesoterodine doses greater than 4 mg daily in adult patients who are also receiving strong CYP3A4 inhibitors. Consider therapy modification

Fexinidazole [INT]: May enhance the QTc-prolonging effect of QT-prolonging Agents (Moderate Risk). Avoid combination

Flibanserin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Flibanserin. Avoid combination

Fluconazole: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

Flurazepam: Saquinavir may increase the serum concentration of Flurazepam. Monitor therapy

Fluticasone (Nasal): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Fluticasone (Nasal). Avoid combination

Fluticasone (Oral Inhalation): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Fluticasone (Oral Inhalation). Management: Use of orally inhaled fluticasone propionate with strong CYP3A4 inhibitors is not recommended. Use of orally inhaled fluticasone furoate with strong CYP3A4 inhibitors should be done with caution. Monitor patients using such a combination more closely. Consider therapy modification

Fosaprepitant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Fosaprepitant. Avoid combination

Fostamatinib: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Fostamatinib. Monitor therapy

Fusidic Acid (Systemic): Saquinavir may increase the serum concentration of Fusidic Acid (Systemic). Fusidic Acid (Systemic) may increase the serum concentration of Saquinavir. Avoid combination

Galantamine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Galantamine. Monitor therapy

Garlic: May decrease the serum concentration of Protease Inhibitors. Management: Concurrent use of garlic supplements with protease inhibitors is not recommended. If this combination is used, monitor closely for altered serum concentrations/effects of protease inhibitors, and particularly for signs/symptoms of therapeutic failure. Consider therapy modification

Gefitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Gefitinib. Monitor therapy

Gilteritinib: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Gilteritinib. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Gilteritinib. Management: Consider alternatives to the use of gilteritinib with strong CYP3A4 inhibitors that prolong the QTc interval whenever possible Consider therapy modification

Glasdegib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Glasdegib. Management: Consider alternatives to this combination when possible. If the combination must be used, monitor closely for evidence of QT interval prolongation and other adverse reactions to glasdegib. Consider therapy modification

Grazoprevir: Saquinavir may increase the serum concentration of Grazoprevir. Avoid combination

GuanFACINE: CYP3A4 Inhibitors (Strong) may increase the serum concentration of GuanFACINE. Management: Reduce the guanfacine dose by 50% when initiating this combination. Consider therapy modification

Halofantrine: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Halofantrine. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Halofantrine. Avoid combination

Haloperidol: Saquinavir may enhance the QTc-prolonging effect of Haloperidol. Avoid combination

Histamine H2 Receptor Antagonists: May increase the serum concentration of Saquinavir. Monitor therapy

HYDROcodone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of HYDROcodone. Monitor therapy

Ibrutinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ibrutinib. Management: Avoid concomitant use of ibrutinib and strong CYP3A4 inhibitors. If a strong CYP3A4 inhibitor must be used short-term (eg, anti-infectives for 7 days or less), interrupt ibrutinib therapy until the strong CYP3A4 inhibitor is discontinued. Avoid combination

Idelalisib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Idelalisib. Monitor therapy

Ifosfamide: CYP3A4 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Ifosfamide. Monitor therapy

Iloperidone: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Iloperidone. Specifically, concentrations of the metabolites P88 and P95 may be increased. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Iloperidone. Management: Reduce iloperidone dose by half when administered with a strong CYP3A4 inhibitor. Consider therapy modification

Imatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Imatinib. Monitor therapy

Imidafenacin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Imidafenacin. Monitor therapy

Irinotecan Products: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Irinotecan Products. Specifically, serum concentrations of SN-38 may be increased. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Irinotecan Products. Avoid combination

Isavuconazonium Sulfate: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Isavuconazonium Sulfate. Specifically, CYP3A4 Inhibitors (Strong) may increase isavuconazole serum concentrations. Management: Combined use is considered contraindicated per US labeling. Lopinavir/ritonavir (and possibly other uses of ritonavir doses less than 400 mg every 12 hours) is treated as a possible exception to this contraindication despite strongly inhibiting CYP3A4. Avoid combination

Istradefylline: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Istradefylline. Management: Limit the maximum istradefylline dose to 20 mg daily when combined with strong CYP3A4 inhibitors and monitor for increased istradefylline effects/toxicities. Consider therapy modification

Itraconazole: May increase the serum concentration of Saquinavir. Saquinavir may increase the serum concentration of Itraconazole. Management: Limit the adult maximum itraconazole dose to 200 mg/day in patients receiving saquinavir/ritonavir. Consider therapy modification

Ivabradine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ivabradine. Avoid combination

Ivacaftor: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ivacaftor. Management: Ivacaftor dose reductions are required; consult full monograph content for age- and weight-specific recommendations. Consider therapy modification

Ivosidenib: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Ivosidenib. Management: Avoid using strong CYP3A4 inhibitors together with ivosidenib if possible. If the combination must be used, reduce the ivosidenib dose to 250 mg once daily. Consider therapy modification

Ixabepilone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ixabepilone. Consider therapy modification

Ketoconazole (Systemic): Saquinavir may increase the serum concentration of Ketoconazole (Systemic). Ketoconazole (Systemic) may increase the serum concentration of Saquinavir. Management: Limit the adult maximum ketoconazole dose to 200 mg/day in patients receiving saquinavir/ritonavir. Consider therapy modification

Lacosamide: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lacosamide. Monitor therapy

Lapatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lapatinib. Management: If an overlap in therapy cannot be avoided, consider reducing lapatinib adult dose to 500 mg/day during, and within 1 week of completing, treatment with the strong CYP3A4 inhibitor. Avoid combination

Larotrectinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Larotrectinib. Management: Avoid use of strong CYP3A4 inhibitors with larotrectinib. If this combination cannot be avoided, reduce the larotrectinib dose by 50%. Increase to previous dose after stopping the inhibitor after a period of 3 to 5 times the inhibitor half-life. Consider therapy modification

Lasmiditan: May increase the serum concentration of P-glycoprotein/ABCB1 Substrates. Avoid combination

Lefamulin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lefamulin. Management: Avoid concomitant use of lefamulin tablets and strong inhibitors of CYP3A4. Avoid combination

Lemborexant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lemborexant. Avoid combination

Lercanidipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lercanidipine. Avoid combination

Levamlodipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Levamlodipine. Monitor therapy

Levobupivacaine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Levobupivacaine. Monitor therapy

Levomethadone: Saquinavir may decrease the serum concentration of Levomethadone. Monitor therapy

Levomilnacipran: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Levomilnacipran. Management: Do not exceed a maximum adult levomilnacipran dose of 80 mg/day in patients also receiving strong CYP3A4 inhibitors. Consider therapy modification

Lidocaine (Systemic): Saquinavir may enhance the arrhythmogenic effect of Lidocaine (Systemic). Saquinavir may increase the serum concentration of Lidocaine (Systemic). Avoid combination

Lomitapide: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lomitapide. Avoid combination

Lopinavir: May enhance the QTc-prolonging effect of Saquinavir. Monitor therapy

Lorlatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lorlatinib. Management: Avoid use of lorlatinib with strong CYP3A4 inhibitors. If the combination cannot be avoided, reduce the lorlatinib dose from 100 mg once daily to 75 mg once daily, or from 75 mg once daily to 50 mg once daily. Consider therapy modification

Lorlatinib: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Avoid concurrent use of lorlatinib with any CYP3A4 substrates for which a minimal decrease in serum concentrations of the CYP3A4 substrate could lead to therapeutic failure and serious clinical consequences. Consider therapy modification

Lovastatin: Protease Inhibitors may increase the serum concentration of Lovastatin. Avoid combination

Lovastatin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lovastatin. Avoid combination

Lumacaftor and Ivacaftor: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lumacaftor and Ivacaftor. Management: When initiating or resuming lumacaftor/ivacaftor after a therapy interruption of 7 days or more, reduce the lumacaftor/ivacaftor dose to 1 tablet daily or 1 packet of oral granules every other day for the first week, and then resume the standard dose. Consider therapy modification

Lumateperone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lumateperone. Avoid combination

Lumefantrine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lumefantrine. Monitor therapy

Lurasidone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lurasidone. Avoid combination

Macitentan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Macitentan. Avoid combination

Manidipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Manidipine. Management: Consider avoiding concomitant use of manidipine and strong CYP3A4 inhibitors. If combined, monitor closely for increased manidipine effects and toxicities. Manidipine dose reductions may be required. Consider therapy modification

Maraviroc: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Maraviroc. Management: Reduce the adult dose of maraviroc to 150 mg twice daily when used with a strong CYP3A4 inhibitor. Do not use maraviroc with strong CYP3A4 inhibitors in patients with Clcr less than 30 mL/min. Consider therapy modification

Meperidine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Meperidine. Monitor therapy

Methadone: Saquinavir may enhance the QTc-prolonging effect of Methadone. Saquinavir may decrease the serum concentration of Methadone. Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation, ventricular arrhythmias, and opioid withdrawal symptoms. Patients with additional risk factors for QTc prolongation may be at even higher risk. Consider therapy modification

MethylPREDNISolone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of MethylPREDNISolone. Management: Consider methylprednisolone dose reduction in patients receiving strong CYP3A4 inhibitors and monitor for increased steroid related adverse effects. Consider therapy modification

Midazolam: Protease Inhibitors may increase the serum concentration of Midazolam. Management: Oral midazolam contraindicated with all protease inhibitors. IV midazolam contraindicated with fosamprenavir and nelfinavir; other protease inhibitors recommend caution, close monitoring, and consideration of lower IV midazolam doses with concurrent use. Avoid combination

Midostaurin: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Midostaurin. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Midostaurin. Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk. Consider therapy modification

MiFEPRIStone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of MiFEPRIStone. Management: Limit mifepristone adult dose, when used for treatment of hyperglycemia in Cushing's syndrome, to a maximum of 900 mg/day when combined with a strong CYP3A4 inhibitor. Monitor for increased mifepristone toxicity regardless of dose or indication. Consider therapy modification

Mirodenafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Mirodenafil. Management: Consider using a lower dose of mirodenafil when used with strong CYP3A4 inhibitors. Monitor for increased mirodenafil effects/toxicities with the use of this combination. Consider therapy modification

Mirtazapine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Mirtazapine. Monitor therapy

Mitotane: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Doses of CYP3A4 substrates may need to be adjusted substantially when used in patients being treated with mitotane. Consider therapy modification

Naldemedine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Naldemedine. Monitor therapy

Nalfurafine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Nalfurafine. Monitor therapy

Naloxegol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Naloxegol. Avoid combination

Nefazodone: Protease Inhibitors may increase the serum concentration of Nefazodone. Management: Consider alternatives to, or reduced doses of, nefazodone in patients treated with HIV protease inhibitors. Monitor patients receiving these combinations closely for toxic effects of nefazodone. Consider therapy modification

Neratinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Neratinib. Avoid combination

Nevirapine: May decrease the serum concentration of Saquinavir. Monitor therapy

Nilotinib: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Nilotinib. Management: Avoid concomitant use of nilotinib and strong CYP3A4 inhibitors that prolong the QTc interval whenever possible. If combined, nilotinib dose reductions are required. Monitor patients for nilotinib toxicities including QTc prolongation and arrhythmias. Consider therapy modification

NiMODipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of NiMODipine. Avoid combination

Nisoldipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Nisoldipine. Avoid combination

Olaparib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Olaparib. Management: Avoid use of strong CYP3A4 inhibitors in patients being treated with olaparib, if possible. If such concurrent use cannot be avoided, the dose of olaparib should be reduced to 100 mg twice daily. Consider therapy modification

Ondansetron: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Ondansetron. Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

Orlistat: May decrease the serum concentration of Antiretroviral Agents. Monitor therapy

Osimertinib: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk. Consider therapy modification

Ospemifene: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ospemifene. Monitor therapy

Oxybutynin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Oxybutynin. Monitor therapy

OxyCODONE: CYP3A4 Inhibitors (Strong) may enhance the adverse/toxic effect of OxyCODONE. CYP3A4 Inhibitors (Strong) may increase the serum concentration of OxyCODONE. Serum concentrations of the active metabolite oxymorphone may also be increased. Consider therapy modification

Palbociclib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Palbociclib. Avoid combination

Panobinostat: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Panobinostat. Management: Reduce the panobinostat dose to 10 mg when it must be used with a strong CYP3A4 inhibitor. Consider therapy modification

Parecoxib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Parecoxib. Monitor therapy

Paricalcitol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Paricalcitol. Monitor therapy

PAZOPanib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of PAZOPanib. Management: Avoid concurrent use of pazopanib with strong inhibitors of CYP3A4 whenever possible. If it is not possible to avoid such a combination, reduce pazopanib adult dose to 400 mg. Further dose reductions may also be required. Consider therapy modification

Pentamidine (Systemic): May enhance the QTc-prolonging effect of Saquinavir. Avoid combination

Pexidartinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Pexidartinib. Management: Avoid use of pexidartinib with strong CYP3A4 inhibitors if possible. If combined use cannot be avoided, the pexidartinib dose should be reduced. Decrease 800 mg or 600 mg daily doses to 200 mg twice daily. Decrease doses of 400 mg/day to 200 mg/day. Consider therapy modification

P-glycoprotein/ABCB1 Inhibitors: May increase the serum concentration of P-glycoprotein/ABCB1 Substrates. P-glycoprotein inhibitors may also enhance the distribution of p-glycoprotein substrates to specific cells/tissues/organs where p-glycoprotein is present in large amounts (e.g., brain, T-lymphocytes, testes, etc.). Monitor therapy

Pimavanserin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Pimavanserin. Management: Decrease the pimavanserin dose to 10 mg daily when combined with strong CYP3A4 inhibitors. Consider therapy modification

Pimecrolimus: CYP3A4 Inhibitors (Strong) may decrease the metabolism of Pimecrolimus. Monitor therapy

Pimozide: Protease Inhibitors may increase the serum concentration of Pimozide. Avoid combination

Pimozide: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Pimozide. Avoid combination

Pimozide: May enhance the QTc-prolonging effect of QT-prolonging Agents (Moderate Risk). Avoid combination

Piperaquine: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Piperaquine. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Piperaquine. Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk. Consider therapy modification

Polatuzumab Vedotin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Polatuzumab Vedotin. Exposure to unconjugated MMAE, the cytotoxic small molecule component of polatuzumab vedotin, may be increased. Monitor therapy

PONATinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of PONATinib. Management: Per ponatinib U.S. prescribing information, the adult starting dose of ponatinib should be reduced to 30 mg daily during treatment with any strong CYP3A4 inhibitor. Consider therapy modification

Pranlukast: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Pranlukast. Monitor therapy

Pravastatin: Saquinavir may decrease the serum concentration of Pravastatin. This effect has only been demonstrated with saquinavir/ritonavir. The individual contributions of saquinavir and ritonavir are unknown. Monitor therapy

Praziquantel: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Praziquantel. Monitor therapy

PrednisoLONE (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of PrednisoLONE (Systemic). Monitor therapy

PredniSONE: CYP3A4 Inhibitors (Strong) may increase the serum concentration of PredniSONE. Monitor therapy

Progestins (Contraceptive): Saquinavir may decrease the serum concentration of Progestins (Contraceptive). Management: Use an alternative or additional method of contraception due to possibly decreased contraceptive effectiveness. Injected depot medroxyprogesterone acetate does not appear to participate in this interaction. Consider therapy modification

Protease Inhibitors: May increase the serum concentration of other Protease Inhibitors. Management: Atazanavir--indinavir combination contraindicated. Tipranavir/ritonavir or atazanavir/ritonavir not recommended with other protease inhibitors (PI). Darunavir/cobicistat not recommended with PI that require boosting.Other combos may require dose changes. Consider therapy modification

Proton Pump Inhibitors: May increase the serum concentration of Saquinavir. Monitor therapy

QT-prolonging Antidepressants (Moderate Risk): QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of QT-prolonging Antidepressants (Moderate Risk). Exceptions: Citalopram. Monitor therapy

QT-prolonging Antipsychotics (Moderate Risk): May enhance the QTc-prolonging effect of Saquinavir. Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Exceptions: CloZAPine; Pimozide; QUEtiapine; Thioridazine. Monitor therapy

QT-prolonging Class IA Antiarrhythmics (Highest Risk): May enhance the QTc-prolonging effect of Saquinavir. Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk. Exceptions: Disopyramide; QuiNIDine. Consider therapy modification

QT-prolonging Class IC Antiarrhythmics (Moderate Risk): May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

QT-prolonging Class III Antiarrhythmics (Highest Risk): May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of QT-prolonging Class III Antiarrhythmics (Highest Risk). Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk. Exceptions: Dronedarone. Consider therapy modification

QT-prolonging Kinase Inhibitors (Highest Risk): May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of QT-prolonging Kinase Inhibitors (Highest Risk). Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk. Exceptions: Ivosidenib. Consider therapy modification

QT-prolonging Miscellaneous Agents (Highest Risk): QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of QT-prolonging Miscellaneous Agents (Highest Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of QT-prolonging Miscellaneous Agents (Highest Risk). Exceptions: Astemizole; Bedaquiline; Cisapride; Delamanid; Terfenadine. Avoid combination

QT-prolonging Miscellaneous Agents (Moderate Risk): QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of QT-prolonging Miscellaneous Agents (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of QT-prolonging Miscellaneous Agents (Moderate Risk). Exceptions: Domperidone; Halofantrine; Midostaurin; Piperaquine; Toremifene. Avoid combination

QT-prolonging Quinolone Antibiotics (Moderate Risk): May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

QUEtiapine: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of QUEtiapine. Management: Reduce the quetiapine dose to one-sixth of the regular dose when combined with strong CYP3A4 inhibitors. Monitor patients for quetiapine toxicities, including QTc prolongation and torsades de pointes. Consider therapy modification

QuiNIDine: Saquinavir may enhance the QTc-prolonging effect of QuiNIDine. Avoid combination

Radotinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Radotinib. Avoid combination

Ramelteon: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ramelteon. Monitor therapy

Ranolazine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ranolazine. Avoid combination

Reboxetine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Reboxetine. Consider therapy modification

Red Yeast Rice: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Red Yeast Rice. Specifically, concentrations of lovastatin and related compounds found in Red Yeast Rice may be increased. Avoid combination

Regorafenib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Regorafenib. Avoid combination

Repaglinide: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Repaglinide. Management: The addition of a CYP2C8 inhibitor to this drug combination may substantially increase the magnitude of increase in repaglinide exposure. Monitor therapy

Retapamulin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Retapamulin. Management: Avoid this combination in patients less than 2 years old. No action is required in other populations. Monitor therapy

Ribociclib: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Ribociclib. Management: Avoid concomitant use of ribociclib and strong CYP3A4 inhibitors that prolong the QTc interval whenever possible. If combined, decrease the ribociclib dose to 400 mg daily. Monitor for ribociclib toxicities including QTc prolongation and arrhythmias. Consider therapy modification

Rifabutin: Saquinavir may increase serum concentrations of the active metabolite(s) of Rifabutin. Rifabutin may decrease the serum concentration of Saquinavir. Saquinavir may increase the serum concentration of Rifabutin. Management: Reduce rifabutin doses. Saquinavir US labeling recommends a decrease of at least 75%, to 150 mg every other day or 3 times per week for adults. Clinical guidelines recommend 150 mg daily or 300 mg 3 times per week when used with saquinavir/ritonavir. Consider therapy modification

RifAMPin: May enhance the adverse/toxic effect of Saquinavir. Specifically, the risk of hepatocellular toxicity may be increased. RifAMPin may decrease the serum concentration of Saquinavir. Avoid combination

Rilpivirine: Saquinavir may enhance the arrhythmogenic effect of Rilpivirine. Saquinavir may increase the serum concentration of Rilpivirine. Avoid combination

Riociguat: Protease Inhibitors may increase the serum concentration of Riociguat. Management: Consider starting with a reduced riociguat dose of 0.5 mg three times a day (for adults). Patients receiving such a combination should also be monitored extra closely for signs or symptoms of hypotension. Consider therapy modification

RomiDEPsin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of RomiDEPsin. Monitor therapy

Rosuvastatin: Protease Inhibitors may increase the serum concentration of Rosuvastatin. Management: Start at the lowest rosuvastatin dose and monitor for toxicity. See full drug interaction monograph for details. Consider therapy modification

Rupatadine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Rupatadine. Avoid combination

Ruxolitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ruxolitinib. Management: This combination should be avoided under some circumstances. See monograph for details. Consider therapy modification

Salmeterol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Salmeterol. Avoid combination

Sarilumab: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

SAXagliptin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of SAXagliptin. Management: Limit the saxagliptin dose to 2.5 mg daily when combined with strong CYP3A4 inhibitors. When using the saxagliptin combination products saxagliptin/dapagliflozin or saxagliptin/dapagliflozin/metformin, avoid use with strong CYP3A4 inhibitors. Consider therapy modification

Sibutramine: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Sibutramine. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Sibutramine. Monitor therapy

Sildenafil: Saquinavir may increase the serum concentration of Sildenafil. Management: Used for PAH: no dose adjustment recommended per US label, Canadian label recommends decrease to 20 mg twice/day. Used for ED: consider a lower starting dose of 25 mg with concurrent saquinavir. Consider therapy modification

Silodosin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Silodosin. Avoid combination

Siltuximab: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

Simeprevir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Simeprevir. Avoid combination

Simeprevir: Protease Inhibitors may increase the serum concentration of Simeprevir. Simeprevir may increase the serum concentration of Protease Inhibitors. Avoid combination

Simvastatin: Protease Inhibitors may increase the serum concentration of Simvastatin. Avoid combination

Simvastatin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Simvastatin. Avoid combination

Sirolimus: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Sirolimus. Management: Consider avoiding concurrent use of sirolimus with strong CYP3A4 inhibitors in order to minimize the risk for sirolimus toxicity. Concomitant use of sirolimus and voriconazole or posaconazole is contraindicated. Consider therapy modification

Solifenacin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Solifenacin. Management: Limit solifenacin doses to 5 mg daily when combined with strong CYP3A4 inhibitors. Consider therapy modification

Sonidegib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Sonidegib. Avoid combination

SORAfenib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of SORAfenib. Monitor therapy

St John's Wort: May increase the metabolism of Protease Inhibitors. Avoid combination

SUFentanil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of SUFentanil. Management: If a strong CYP3A4 inhibitor is initiated in a patient on sufentanil, consider a sufentanil dose reduction and monitor for increased sufentanil effects and toxicities (eg, respiratory depression). Consider therapy modification

SUNItinib: Saquinavir may increase the serum concentration of SUNItinib. Avoid combination

Suvorexant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Suvorexant. Avoid combination

Tacrolimus (Systemic): Saquinavir may increase the serum concentration of Tacrolimus (Systemic). Avoid combination

Tacrolimus (Topical): Protease Inhibitors may decrease the metabolism of Tacrolimus (Topical). Monitor therapy

Tadalafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tadalafil. Management: Recommendations regarding use of tadalafil in patients also receiving strong CYP3A4 inhibitors may vary based on indication and/or international labeling. Consult appropriate product labeling. Consider therapy modification

Tamsulosin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tamsulosin. Avoid combination

Tasimelteon: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tasimelteon. Monitor therapy

Tazemetostat: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tazemetostat. Avoid combination

Telithromycin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Telithromycin. Monitor therapy

Temsirolimus: Protease Inhibitors may enhance the adverse/toxic effect of Temsirolimus. Levels of sirolimus, the active metabolite, may be increased, likely due to inhibition of CYP-mediated metabolism. Consider therapy modification

Temsirolimus: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Temsirolimus. Management: Avoid concomitant use of temsirolimus and strong CYP3A4 inhibitors whenever possible. If combined, decrease temsirolimus dose to 12.5 mg per week and monitor patients for increased temsirolimus effects and toxicities. Consider therapy modification

Terfenadine: QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may enhance the QTc-prolonging effect of Terfenadine. QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Terfenadine. Avoid combination

Tetrahydrocannabinol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tetrahydrocannabinol. Monitor therapy

Tetrahydrocannabinol and Cannabidiol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tetrahydrocannabinol and Cannabidiol. Monitor therapy

Tezacaftor and Ivacaftor: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tezacaftor and Ivacaftor. Management: When combined with strong CYP3A4 inhibitors, tezacaftor/ivacaftor should be administered in the morning, twice a week, approximately 3 to 4 days apart. No evening doses of ivacaftor alone should be administered. Consider therapy modification

Thioridazine: Saquinavir may enhance the QTc-prolonging effect of Thioridazine. Avoid combination

Thiotepa: CYP3A4 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Thiotepa. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Thiotepa. Management: Thiotepa prescribing information recommends avoiding concomitant use of thiotepa and strong CYP3A4 inhibitors. If concomitant use is unavoidable, monitor for adverse effects and decreased efficacy. Consider therapy modification

Ticagrelor: CYP3A4 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Ticagrelor. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ticagrelor. Avoid combination

Tipranavir: May decrease the serum concentration of Protease Inhibitors. Avoid combination

Tocilizumab: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

Tofacitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tofacitinib. Management: Tofacitinib dose reductions are recommended when combined with strong CYP3A4 inhibitors. Recommended dose adjustments vary by tofacitinib formulation and therapeutic indication. See full monograph for details. Consider therapy modification

Tolterodine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tolterodine. Management: The maximum recommended adult dose of tolterodine is 2 mg/day when used together with a strong CYP3A4 inhibitor. Consider therapy modification

Tolvaptan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tolvaptan. Avoid combination

Toremifene: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Toremifene. Management: Avoid concomitant use of toremifene and strong CYP3A4 inhibitors that prolong the QTc interval whenever possible. If combined, monitor patients for toremifene toxicities including QTc prolongation and TdP. Consider therapy modification

Trabectedin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Trabectedin. Avoid combination

TraMADol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of TraMADol. Monitor therapy

TraZODone: Saquinavir may enhance the QTc-prolonging effect of TraZODone. Saquinavir may increase the serum concentration of TraZODone. Avoid combination

Triazolam: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Triazolam. Avoid combination

Tricyclic Antidepressants: Protease Inhibitors may increase the serum concentration of Tricyclic Antidepressants. Monitor therapy

Ubrogepant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ubrogepant. Avoid combination

Udenafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Udenafil. Avoid combination

Ulipristal: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ulipristal. Management: This is specific for when ulipristal is being used for signs/symptoms of uterine fibroids (Canadian indication). When ulipristal is used as an emergency contraceptive, patients receiving this combo should be monitored for ulipristal toxicity. Avoid combination

Upadacitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Upadacitinib. Monitor therapy

Valbenazine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Valbenazine. Management: Reduce the valbenazine dose to 40 mg daily when combined with strong CYP3A4 inhibitors. Consider therapy modification

Valproate Products: Protease Inhibitors may decrease the serum concentration of Valproate Products. Monitor therapy

Vardenafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vardenafil. Management: Recommendations regarding concomitant use of vardenafil with strong CYP3A4 inhibitors may vary depending on brand name (e.g., Levitra, Staxyn) or by international labeling. See full drug interaction monograph for details. Consider therapy modification

Vemurafenib: May enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Vemurafenib. Management: Avoid concomitant use of vemurafenib and strong CYP3A4 inhibitors that prolong the QTc interval whenever possible. If combined monitor patients for vemurafenib toxicities including QTc prolongation and TdP. Consider therapy modification

Venetoclax: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Venetoclax. Management: This combination is contraindicated during venetoclax initiation and ramp-up in patients with CLL/SLL. Reduced venetoclax doses are required during ramp-up for patients with AML, and reduced doses are required for all patients during maintenance therapy. Consider therapy modification

Vilanterol: May increase the serum concentration of CYP3A4 Inhibitors (Strong). Monitor therapy

Vilazodone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vilazodone. Management: Limit maximum adult vilazodone dose to 20 mg daily in patients receiving strong CYP3A4 inhibitors. The original vilazodone dose can be resumed following discontinuation of the strong CYP3A4 inhibitor. Consider therapy modification

VinCRIStine (Liposomal): CYP3A4 Inhibitors (Strong) may increase the serum concentration of VinCRIStine (Liposomal). Avoid combination

Vindesine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vindesine. Monitor therapy

Vinflunine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vinflunine. Avoid combination

Vinorelbine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vinorelbine. Monitor therapy

Vorapaxar: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vorapaxar. Avoid combination

Voriconazole: Saquinavir may enhance the QTc-prolonging effect of Voriconazole. Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

Voxelotor: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Voxelotor. Management: Avoid concomitant use of voxelotor and strong CYP3A4 inhibitors. If concomitant use is unavoidable, reduce the voxelotor dose to 1,000 mg once daily. Consider therapy modification

Warfarin: Saquinavir may increase the serum concentration of Warfarin. Monitor therapy

Zanubrutinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Zanubrutinib. Management: Decrease the zanubrutinib dose to 80 mg once daily during coadministration with a strong CYP3A4 inhibitor. Further dose adjustments may be required for zanubrutinib toxicities, refer to prescribing information for details. Consider therapy modification

Zidovudine: Protease Inhibitors may decrease the serum concentration of Zidovudine. Monitor therapy

Zolpidem: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Zolpidem. Monitor therapy

Zopiclone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Zopiclone. Management: The initial starting adult dose of zopiclone should not exceed 3.75 mg if combined with a strong CYP3A4 inhibitor. Monitor patients for signs and symptoms of zopiclone toxicity if these agents are combined. Consider therapy modification

Zuclopenthixol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Zuclopenthixol. Management: Consider zuclopenthixol dosage reduction with concomitant use of a strong CYP3A4 inhibitor (eg, ketoconazole) in poor CYP2D6 metabolizers or with strong CYP2D6 inhibitors (eg, paroxetine). Monitor for increased zuclopenthixol levels/toxicity. Consider therapy modification

Adverse Reactions

Incidence data for saquinavir soft gel capsule formulation (no longer available) in combination with ritonavir:

10%: Gastrointestinal: Nausea (11%)

1% to 10%:

Cardiovascular: Chest pain

Central nervous system: Fatigue (6%), anxiety, depression, headache, insomnia, pain, paresthesia

Dermatologic: Pruritus (3%), skin rash (3%), eczema (2%), cheilosis (≤2%), xeroderma (≤2%), warts

Endocrine & metabolic: Lipodystrophy (5%), hyperglycemia (3%), change in libido, hypoglycemia, hyperkalemia

Gastrointestinal: Diarrhea (8%), vomiting (7%), abdominal pain (6%), constipation (2%), abdominal distress, decreased appetite, dysgeusia, dyspepsia, flatulence, increased serum amylase, oral mucosa ulcer

Hepatic: Increased serum ALT, increased serum AST, increased serum bilirubin

Infection: Influenza (3%)

Neuromuscular & skeletal: Back pain (2%), increased creatine phosphokinase, weakness

Respiratory: Pneumonia (5%), bronchitis (3%), sinusitis (3%)

Miscellaneous: Fever (3%)

Frequency not defined; reported for hard or soft gel capsule with/without ritonavir:

Cardiovascular: Heart valve disease (including murmur), hypertension, hypotension, peripheral vasoconstriction, prolongation P-R interval on ECG, prolonged Q-T interval on ECG, syncope, thrombophlebitis

Central nervous system: Agitation, amnesia, ataxia, colic, confusion, drowsiness, hallucination, hyperreflexia, hyporeflexia, neuropathy, poliomyelitis, progressive multifocal leukoencephalopathy, psychosis, seizure, speech disturbance

Dermatologic: Alopecia, bullous dermatitis, dermal ulcer, dermatitis, erythema, maculopapular rash, skin photosensitivity, Stevens-Johnson syndrome, urticaria

Endocrine & metabolic: Dehydration, diabetes mellitus, electrolyte disturbance, increased gamma-glutamyl transferase, increased lactate dehydrogenase, increased thyroid stimulating hormone level

Gastrointestinal: Bloody stools, dysphagia, esophagitis, gastritis, intestinal obstruction, pancreatitis, stomatitis

Genitourinary: Benign prostatic hypertrophy, hematuria, impotence, urinary tract infection

Hematologic & oncologic: Acute myelocytic leukemia, anemia (including hemolytic), leukopenia, neutropenia, pancytopenia, rectal hemorrhage, splenomegaly, thrombocytopenia

Hepatic: Ascites, hepatic disease (exacerbation), hepatitis, hepatomegaly, hepatosplenomegaly, increased serum alkaline phosphatase, jaundice

Immunologic: Immune reconstitution syndrome

Infection: Infection (bacterial, fungal, viral)

Neuromuscular & skeletal: Arthritis

Ophthalmic: Blepharitis, visual disturbance

Otic: Auditory impairment, otitis, tinnitus

Renal: Nephrolithiasis

Respiratory: Cyanosis, dyspnea, hemoptysis, pharyngitis, upper respiratory tract infection

<1%, postmarketing, and/or case reports: Atrioventricular block (second or third degree), autoimmune disease, torsades de pointes

Warnings/Precautions

Concerns related to adverse effects:

• Altered cardiac conduction: Saquinavir/ritonavir prolongs the QT interval, potentially leading to torsade de pointes, and prolongs the PR interval, potentially leading to heart block. Second- or third-degree AV block has been reported (rare). An ECG should be performed for all patients prior to starting saquinavir/ritonavir therapy; do not initiate therapy in patients with a baseline QT interval ≥450 msec or diagnosed with long QT syndrome. If baseline QT interval <450 msec, may initiate saquinavir/ritonavir, but a subsequent ECG is recommended after ~10 days of therapy. For patients already receiving saquinavir/ritonavir that require concomitant therapy with another medication with the potential to prolong the QT interval, may initiate the concomitant therapy if baseline QT interval <450 msec, but a subsequent ECG is recommended after 3 to 4 days of therapy. If subsequent QT interval is prolonged over baseline by >20 msec, therapy should be discontinued. Patients who may be at increased risk for QT- or PR-interval prolongation include those with heart failure, bradyarrhythmias, hepatic impairment, electrolyte abnormalities, ischemic heart disease, cardiomyopathy, structural heart disease, or those with pre-existing cardiac conduction abnormalities; ECG monitoring is recommended for these patients. Discontinue therapy if significant arrhythmia or PR prolongation occur.
• Fat redistribution: May cause redistribution of fat (eg, buffalo hump, peripheral wasting with increased abdominal girth, cushingoid appearance).
• Immune reconstitution syndrome: Patients may develop immune reconstitution syndrome resulting in the occurrence of an inflammatory response to an indolent or residual opportunistic infection during initial HIV treatment or activation of autoimmune disorders (eg, Graves’ disease, polymyositis, Guillain-Barré syndrome) later in therapy; further evaluation and treatment may be required.
• Increased cholesterol: Increases in total cholesterol and triglycerides have been reported; screening should be done prior to therapy and periodically throughout treatment.
• Photosensitivity reactions: May cause photosensitivity reactions (eg, exposure to sunlight may cause severe sunburn, skin rash, redness, or itching); advise patient to avoid exposure to sunlight and artificial light sources (eg, sunlamps, tanning bed/booth) and to wear protective clothing, wide-brimmed hats, sunglasses, and lip sunscreen (SPF ≥15). Sunscreen should be used (broad-spectrum sunscreen or physical sunscreen [preferred] or sunblock with SPF ≥15) (HHS [pediatric] 2016).

Disease-related concerns:

• Diabetes: Changes in glucose tolerance, hyperglycemia, exacerbation of diabetes, DKA, and new-onset diabetes mellitus have been reported in patients receiving protease inhibitors.
• Electrolyte imbalances: Correct electrolyte abnormalities prior to treatment and monitor potassium and magnesium levels during therapy.
• Hemophilia A or B: Use with caution in patients with hemophilia A or B; increased bleeding during protease inhibitor therapy has been reported.
• Hepatic impairment: Use with caution in patients with underlying mild-to-moderate hepatic disease, including hepatitis B or C, cirrhosis, or chronic alcoholism; may cause hepatitis, portal hypertension, jaundice, and/or exacerbate preexisting hepatic dysfunction; contraindicated in severe hepatic impairment. Discontinue saquinavir/ritonavir if severe hepatotoxicity occurs.
• Lactose intolerance: Contains lactose; use not recommended in patients with rare hereditary disorders of lactose intolerance (eg, Lapp lactase deficiency, glucose-galactose malabsorption).

Concurrent drug therapy issues:

• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Other warnings/precautions:

• Appropriate use: Must be used in combination with ritonavir. Not recommended for use in combination with cobicistat; dosing recommendations for this combination have not been established.
• Cross-resistance to other HIV drugs: Continued administration after loss of viral suppression efficacy may increase the likelihood of cross-resistance to other protease inhibitors. Promptly discontinue therapy if viral suppression response is lost.

Monitoring Parameters

Monitor ECG (prior to therapy and after 3 to 4 days of therapy [patients already receiving saquinavir/ritonavir and initiating concomitant QT prolonging therapy] or after ~10 days of therapy [patients initiating saquinavir/ritonavir]); serum potassium and magnesium levels, triglycerides and cholesterol (prior to initiation and periodically during therapy); viral load, CD4 count; glucose

Pregnancy

Pregnancy Considerations

Saquinavir crosses the human placenta.

Outcome information specific to saquinavir use in pregnancy is no longer being reviewed and updated in the Health and Humans Services (HHS) perinatal guidelines. Maternal antiretroviral therapy (ART) may be associated with adverse pregnancy outcomes including preterm delivery, stillbirth, low birth weight, and small for gestational age infants. Actual risks may be influenced by maternal factors, such as disease severity, gestational age at initiation of therapy, and specific ART regimen; therefore, close fetal monitoring is recommended. Because there is clear benefit to appropriate treatment, maternal ART should not be withheld due to concerns for adverse neonatal outcomes. Long-term follow-up is recommended for all infants exposed to antiretroviral medications; children without HIV but who were exposed to ART in utero and develop significant organ system abnormalities of unknown etiology (particularly of the CNS or heart) should be evaluated for potential mitochondrial dysfunction. Hyperglycemia, new onset of diabetes mellitus, or diabetic ketoacidosis have been reported with protease inhibitors (PI); it is not clear if pregnancy increases this risk. Consider performing the standard glucose screening test earlier in pregnancy in women who initiated PI therapy prior to conception.

Based on the HHS perinatal HIV guidelines, saquinavir is not one of the recommended antiretroviral agents for use during pregnancy or females living with HIV who are trying to conceive.

In general, ART is recommended for all pregnant females living with HIV to keep the viral load below the limit of detection and reduce the risk of perinatal transmission. Therapy should be individualized following a discussion of the potential risks and benefits of treatment during pregnancy. Monitoring of pregnant females is more frequent than in nonpregnant adults. ART should be continued postpartum for all females living with HIV and can be modified after delivery.

Health care providers are encouraged to enroll pregnant females exposed to antiretroviral medications as early in pregnancy as possible in the Antiretroviral Pregnancy Registry (1-800-258-4263 or http://www.APRegistry.com). Health care providers caring for pregnant females living with HIV and their infants may contact the National Perinatal HIV Hotline (1-888-448-8765) for clinical consultation (HHS [perinatal] 2019).

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)
• Patient may experience abdominal pain, nausea, vomiting, loss of strength and energy, or diarrhea. Have patient report immediately to prescriber signs of infection, signs of liver problems (dark urine, fatigue, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or yellow skin), signs of high blood sugar (confusion, fatigue, increased thirst, increased hunger, passing a lot of urine, flushing, fast breathing, or breath that smells like fruit), signs of severe cerebrovascular disease (change in strength on one side is greater than the other, difficulty speaking or thinking, change in balance, or vision changes), dizziness; passing out; fast heartbeat; abnormal heartbeat; change in body fat; or signs of Stevens-Johnson syndrome/toxic epidermal necrolysis (red, swollen, blistered, or peeling skin [with or without fever]; red or irritated eyes; or sores in mouth, throat, nose, or eyes) (HCAHPS).
• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.