Dronedarone

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Tablet, Oral:

Multaq: 400 mg

Pharmacology

Mechanism of Action

A noniodinated antiarrhythmic agent structurally related to amiodarone exhibiting properties of all 4 antiarrhythmic classes. Dronedarone inhibits sodium (I_Na) and potassium (I_kr, I_kS, I_k1, and I_k-ACh) channels resulting in prolongation of the action potential and refractory period in myocardial tissue without reverse-use dependent effects; decreases AV conduction and sinus node function through inhibition of calcium (I_Ca-L) channels and beta₁-receptor blocking activity. Similar to amiodarone, dronedarone also inhibits alpha₁-receptor mediated increases in blood pressure.

Pharmacokinetics/Pharmacodynamics

Distribution

V_d: ~1400 L

Metabolism

Hepatic via CYP3A4 to active N-debutyl metabolite (¹/₁₀ to ¹/₃ as potent as dronedarone) and other inactive metabolites

Excretion

Feces (84% mainly as metabolites); urine (~6% mainly as metabolites)

Time to Peak

Plasma: 3 to 6 hours

Half-Life Elimination

13 to 19 hours

Protein Binding

>98%

Use in Specific Populations

Special Populations: Hepatic Function Impairment

Dronedarone mean exposure increased 1.3-fold and mean exposure of the N-debutyl metabolite decreased by 50% in patients with moderate hepatic impairment.

Special Populations: Elderly

Dronedarone exposure is 23% higher in patients 65 years and older.

Special Populations: Gender

Dronedarone exposure is 30% higher in females than in males.

Special Populations: Race

Asian (Japanese) males have about a 2-fold higher exposure than white males.

Use: Labeled Indications

Paroxysmal or persistent atrial fibrillation: To reduce the risk of hospitalization for atrial fibrillation (AF) in patients in sinus rhythm with a history of paroxysmal or persistent AF

Use: Off Label

Atrial fibrillation in patients with hypertrophic cardiomyopathy (alternative antiarrhythmic)yes

Based on the 2011 American College of Cardiology Foundation/American Heart Association (ACCF/AHA) guideline for the diagnosis and treatment of hypertrophic cardiomyopathy (HCM) and the 2014 American Heart Association/American College of Cardiology/Heart Rhythm Society (AHA/ACC/HRS) guideline for the management of patients with atrial fibrillation (AF), dronedarone may be considered an alternative to amiodarone or disopyramide (combined with a beta-blocker or a nondihydropyridine calcium channel blocker) for the treatment of AF in patients with HCM, especially in those with an implantable cardioverter-defibrillator (ICD), but clinical experience is limited.

Contraindications

Hypersensitivity to dronedarone or any component of the formulation; permanent atrial fibrillation (patients in whom normal sinus rhythm will not or cannot be restored); symptomatic heart failure (heart failure with recent [within the last 4 weeks] decompensation requiring hospitalization or NYHA Class III or IV symptoms); liver or lung toxicity related to previous amiodarone use; second-degree or third-degree atrioventricular block or sick sinus syndrome (except when used in conjunction with a functioning artificial pacemaker); bradycardia <50 bpm; concomitant use of strong CYP3A4 inhibitors (eg, ketoconazole, itraconazole, voriconazole, cyclosporine, telithromycin, clarithromycin, nefazodone, ritonavir); concomitant use of drugs or herbal products known to prolong the QT interval increasing the risk for torsade de pointes (eg, phenothiazine antipsychotics, tricyclic antidepressants, certain oral macrolide antibiotics, class I and III antiarrhythmics); QT_c (Bazett) interval ≥500 msec or PR interval >280 msec; severe hepatic impairment; pregnancy; breastfeeding

Canadian labeling: Additional contraindications (not in US labeling): Permanent atrial fibrillation of any duration where sinus rhythm cannot be restored and further attempts to restore it are no longer considered; history of or current heart failure regardless of NYHA class; left ventricular systolic dysfunction; complete bundle branch block, distal block, sinus node dysfunction, or atrial conduction defects (except when used in conjunction with a functioning pacemaker); unstable hemodynamic condition

Dosage and Administration

Dosing: Adult

Note: Prior to initiation of dronedarone, class I or III antiarrhythmics (eg, amiodarone, flecainide, propafenone, quinidine, disopyramide, dofetilide, sotalol) or drugs that are strong inhibitors of CYP3A (eg, ketoconazole, itraconazole, voriconazole, cyclosporine, telithromycin, clarithromycin, nefazodone, ritonavir) must be discontinued.

Paroxysmal or persistent atrial fibrillation: Note: For use in patients in normal sinus rhythm with a history of paroxysmal or persistent atrial fibrillation; should not be used for patients permanently in atrial fibrillation to control ventricular rate; should not be used in patients with symptomatic heart failure, defined as recent (within 4 weeks) decompensated heart failure requiring hospitalization or NYHA Class III or IV symptoms (AHA/ACC [January 2014]).

Oral: 400 mg twice daily with meals

Dosing: Geriatric

Refer to adult dosing.

Administration

Oral: Administer with morning and evening meal.

Dietary Considerations

Take with a meal. Avoid coadministration with grapefruit/grapefruit juice.

Storage

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

Drug Interactions

Abemaciclib: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Abemaciclib. Monitor therapy

Acalabrutinib: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Acalabrutinib. Management: Reduce acalabrutinib dose to 100 mg once daily with concurrent use of a moderate CYP3A4 inhibitor. Monitor patient closely for both acalabrutinib response and evidence of adverse effects with any concurrent use. Consider therapy modification

Afatinib: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Afatinib. Management: Reduce afatinib by 10 mg if not tolerated. Some non-US labeling recommends avoiding combination if possible. If used, administer the P-gp inhibitor simultaneously with or after the dose of afatinib. Consider therapy modification

Amiodarone: QT-prolonging Class III Antiarrhythmics (Highest Risk) may enhance the QTc-prolonging effect of Amiodarone. 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

Amisulpride: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Amisulpride. Management: Consider alternatives to this combination. Patients with other risk factors (eg, older age, female sex, bradycardia, hypokalemia, hypomagnesemia, heart disease, and higher drug concentrations) are likely at greater risk for these toxicities. Consider therapy modification

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

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

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

ARIPiprazole: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of ARIPiprazole. Management: Monitor for increased aripiprazole pharmacologic effects. Aripiprazole dose adjustments may or may not be required based on concomitant therapy and/or indication. Consult full interaction monograph for specific recommendations. Monitor therapy

ARIPiprazole: CYP2D6 Inhibitors (Weak) may increase the serum concentration of ARIPiprazole. Management: Monitor for increased aripiprazole pharmacologic effects. Aripiprazole dose adjustments may or may not be required based on concomitant therapy and/or indication. Consult full interaction monograph for specific recommendations. Monitor therapy

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

AtorvaSTATin: Dronedarone may increase the serum concentration of AtorvaSTATin. Monitor therapy

Avanafil: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Avanafil. Management: The maximum avanafil adult dose is 50 mg per 24-hour period when used together with a moderate CYP3A4 inhibitor. Patients receiving such a combination should also be monitored more closely for evidence of adverse effects. Consider therapy modification

Avapritinib: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Avapritinib. Management: Avoid use of moderate CYP3A4 inhibitors with avapritinib. If this combination cannot be avoided, reduce the avapritinib dose from 300 mg once daily to 100 mg once daily. Consider therapy modification

Axitinib: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Axitinib. Monitor therapy

Azithromycin (Systemic): QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Azithromycin (Systemic). Management: Consider alternatives to this combination. Patients with other risk factors (eg, older age, female sex, bradycardia, hypokalemia, hypomagnesemia, heart disease, and higher drug concentrations) are likely at greater risk for these toxicities. Consider therapy modification

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

Beta-Blockers: Dronedarone may enhance the bradycardic effect of Beta-Blockers. Dronedarone may increase the serum concentration of Beta-Blockers. This likely applies only to those agents that are metabolized by CYP2D6. Management: Use lower initial beta-blocker doses; adequate tolerance of the combination, based on ECG findings, should be confirmed prior to any increase in beta-blocker dose. Consider therapy modification

Betrixaban: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Betrixaban. Management: Decrease the adult betrixaban dose to an initial single dose of 80 mg followed by 40 mg once daily if combined with a P-glycoprotein inhibitor. Consider therapy modification

Bilastine: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Bilastine. Management: Consider alternatives when possible; bilastine should be avoided in patients with moderate to severe renal insufficiency who are receiving p-glycoprotein inhibitors. Consider therapy modification

Blonanserin: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Blonanserin. Monitor therapy

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

Bosentan: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Bosentan. Management: Concomitant use of both a CYP2C9 inhibitor and a CYP3A inhibitor or a single agent that inhibits both enzymes with bosentan is likely to cause a large increase in serum concentrations of bosentan and is not recommended. See monograph for details. Monitor therapy

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

Bradycardia-Causing Agents: May enhance the bradycardic effect of other Bradycardia-Causing Agents. Monitor therapy

Brentuximab Vedotin: P-glycoprotein/ABCB1 Inhibitors 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 (Moderate) may increase the serum concentration of Brexpiprazole. Management: The brexpiprazole dose should be reduced to 25% of usual if used together with both a moderate CYP3A4 inhibitor and a strong or moderate CYP2D6 inhibitor, or if a moderate CYP3A4 inhibitor is used in a CYP2D6 poor metabolizer. Monitor therapy

Brigatinib: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Brigatinib. Management: Avoid concurrent use of brigatinib with moderate CYP3A4 inhibitors when possible. If such a combination cannot be avoided, reduce the dose of brigatinib by approximately 40% (ie, from 180 mg to 120 mg, from 120 mg to 90 mg, or from 90 mg to 60 mg). Consider therapy modification

Bromocriptine: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Bromocriptine. Management: The bromocriptine dose should not exceed 1.6 mg daily with use of a moderate CYP3A4 inhibitor. The Cycloset brand specifically recommends this dose limitation, but other bromocriptine products do not make such specific recommendations. Consider therapy modification

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

Budesonide (Topical): CYP3A4 Inhibitors (Moderate) 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

Calcium Channel Blockers (Nondihydropyridine): May enhance the AV-blocking effect of Dronedarone. Other electrophysiologic effects of Dronedarone may also be increased. Calcium Channel Blockers (Nondihydropyridine) may increase the serum concentration of Dronedarone. Dronedarone may increase the serum concentration of Calcium Channel Blockers (Nondihydropyridine). Management: Use lower starting doses of the nondihydropyridine calcium channel blockers (i.e., verapamil, diltiazem), and only consider increasing calcium channel blocker dose after obtaining ECG-based evidence that the combination is being well-tolerated. Exceptions: Bepridil. Consider therapy modification

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

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

Chloroquine: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Chloroquine. Management: Consider alternatives to this 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

ChlorproMAZINE: Dronedarone may enhance the QTc-prolonging effect of ChlorproMAZINE. Avoid combination

Cilostazol: CYP3A4 Inhibitors (Moderate) 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 moderate inhibitors of CYP3A4. Consider therapy modification

Citalopram: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Citalopram. Avoid combination

Clarithromycin: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Clarithromycin. Avoid combination

Clofazimine: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Clofazimine. Management: Consider alternatives to this 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

CloZAPine: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of CloZAPine. Management: Consider alternatives to this combination. Patients with other risk factors (eg, older age, female sex, bradycardia, hypokalemia, hypomagnesemia, heart disease, and higher drug concentrations) are likely at greater risk for these toxicities. Consider therapy modification

Cobimetinib: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Cobimetinib. Management: Avoid the concomitant use of cobimetinib and moderate CYP3A4 inhibitors. If concurrent short term (14 days or less) use cannot be avoided, reduce the cobimetinib dose to 20 mg daily. Avoid combination

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

Colchicine: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Colchicine. Management: Reduce colchicine dose as directed when using with a moderate CYP3A4 inhibitor, and increase monitoring for colchicine-related toxicity. See full monograph for details. Use extra caution in patients with impaired renal and/or hepatic function. Consider therapy modification

Colchicine: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Colchicine. Colchicine distribution into certain tissues (e.g., brain) may also be increased. Management: Colchicine is contraindicated in patients with impaired renal or hepatic function who are also receiving a p-glycoprotein inhibitor. In those with normal renal and hepatic function, reduce colchicine dose as directed. See full monograph for details. Consider therapy modification

Conivaptan: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Avoid combination

CycloSPORINE (Systemic): May increase the serum concentration of Dronedarone. Avoid combination

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

CYP3A4 Inducers (Strong): May decrease the serum concentration of Dronedarone. Avoid combination

CYP3A4 Inhibitors (Moderate): May decrease the metabolism of CYP3A4 Substrates (High risk with Inhibitors). Monitor therapy

CYP3A4 Inhibitors (Strong): May increase the serum concentration of Dronedarone. Management: Drugs listed as exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Exceptions: Ceritinib; Clarithromycin; Saquinavir; Voriconazole. Avoid combination

CYP3A4 Substrates (High risk with Inhibitors): CYP3A4 Inhibitors (Moderate) may decrease the metabolism of CYP3A4 Substrates (High risk with Inhibitors). Exceptions: Alitretinoin (Systemic); Praziquantel; Trabectedin; Vinorelbine. Monitor therapy

Dabigatran Etexilate: Dronedarone may increase the serum concentration of Dabigatran Etexilate. Management: Dose reductions and/or avoidance of this combination may be necessary. Specific recommendations vary by renal function and indication for dabigatran. Refer to full monograph for details. Consider therapy modification

Dabrafenib: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Seek alternatives to the CYP3A4 substrate when possible. If concomitant therapy cannot be avoided, monitor clinical effects of the substrate closely (particularly therapeutic effects). Consider therapy modification

Dapoxetine: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Dapoxetine. Management: The dose of dapoxetine should be limited to 30 mg per day when used together with a moderate inhibitor of CYP3A4. Consider therapy modification

Dasatinib: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Dasatinib. Management: Consider alternatives to this combination. Patients with other risk factors (eg, older age, female sex, bradycardia, hypokalemia, hypomagnesemia, heart disease, and higher drug concentrations) are likely at greater risk for these toxicities. Consider therapy modification

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

Deflazacort: CYP3A4 Inhibitors (Moderate) 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

Digoxin: May enhance the AV-blocking effect of Dronedarone. Digoxin may also enhance the other electrophysiologic effects of Dronedarone. Dronedarone may increase the serum concentration of Digoxin. Management: Avoid concurrent use of digoxin when possible. If concurrent use is necessary, reduce adult digoxin dose by 50%, monitor digoxin concentration closely, and increase monitoring for both clinical response to therapy and the occurrence of adverse effects. Consider therapy modification

DOCEtaxel: Dronedarone may increase the serum concentration of DOCEtaxel. Management: Avoid this combination whenever possible. If this combination must be used, consider using a reduced docetaxel dose, and/or increase monitoring for evidence of serious docetaxel toxicity (e.g., neutropenia, mucositis, etc.). Consider therapy modification

Domperidone: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Domperidone. Avoid combination

Doxepin-Containing Products: May enhance the QTc-prolonging effect of Dronedarone. Avoid combination

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

DOXOrubicin (Conventional): P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of DOXOrubicin (Conventional). Management: Seek alternatives to P-glycoprotein 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 (Moderate) may increase the serum concentration of Dronabinol. Monitor therapy

Droperidol: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Droperidol. Management: Consider alternatives to this combination. Patients with other risk factors (eg, older age, female sex, bradycardia, hypokalemia, hypomagnesemia, heart disease, and higher drug concentrations) are likely at greater risk for these toxicities. Consider therapy modification

Duvelisib: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Monitor therapy

Edoxaban: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Edoxaban. Management: See full monograph for details. Reduced doses are recommended for patients receiving edoxaban for venous thromboembolism in combination with certain P-gp inhibitors. Similar dose adjustment is not recommended for edoxaban use in atrial fibrillation. Consider therapy modification

Eletriptan: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Eletriptan. Management: The use of eletriptan within 72 hours of a moderate CYP3A4 inhibitor should be avoided. Consider therapy modification

Elexacaftor, Tezacaftor, and Ivacaftor: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Elexacaftor, Tezacaftor, and Ivacaftor. Management: When combined with moderate CYP3A4 inhibitors, two elexacaftor/tezacaftor/ivacaftor (100 mg/50 mg/75 mg) tablets should be given in the morning, every other day. Ivacaftor (150 mg) should be given in the morning, every other day on alternate days. Consider therapy modification

Eliglustat: CYP3A4 Inhibitors (Moderate) 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

Encorafenib: May enhance the QTc-prolonging effect of Dronedarone. Dronedarone may increase the serum concentration of Encorafenib. Management: Avoid using dronedarone with encorafenib if possible. If the combination must be used, reduce the encorafenib dose prior to initiation of dronedarone and monitor QT interval. See full monograph for details. Consider therapy modification

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

Eplerenone: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Eplerenone. Management: When used concomitantly with moderate inhibitors of CYP3A4, eplerenone dosing recommendations vary by indication and international labeling. See full drug interaction monograph for details. Consider therapy modification

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

Erdafitinib: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Monitor therapy

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

Escitalopram: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Escitalopram. Management: Consider alternatives to this combination. Patients with other risk factors (eg, older age, female sex, bradycardia, hypokalemia, hypomagnesemia, heart disease, and higher drug concentrations) are likely at greater risk for these toxicities. Consider therapy modification

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

Everolimus: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Everolimus. Management: Everolimus dose reductions are required for most indications. See full monograph or prescribing information for specific dose adjustment and monitoring recommendations. Consider therapy modification

Everolimus: Inhibitors of CYP3A4 (Moderate) and P-glycoprotein may increase the serum concentration of Everolimus. Management: Everolimus dose reductions are required for most indications. See full monograph or prescribing information for specific dose adjustment and monitoring recommendations. Consider therapy modification

FentaNYL: CYP3A4 Inhibitors (Moderate) 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

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

Fexinidazole [INT]: Bradycardia-Causing Agents may enhance the arrhythmogenic effect of Fexinidazole [INT]. Avoid combination

Fingolimod: May enhance the QTc-prolonging effect of QT-prolonging Class III Antiarrhythmics (Highest Risk). Avoid combination

Flecainide: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Flecainide. Management: Consider alternatives to this combination. Patients with other risk factors (eg, older age, female sex, bradycardia, hypokalemia, hypomagnesemia, heart disease, and higher drug concentrations) are likely at greater risk for these toxicities. Consider therapy modification

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

Flupentixol: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Flupentixol. Avoid combination

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

Fosnetupitant: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Monitor therapy

Fusidic Acid (Systemic): May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Avoid combination

Gadobenate Dimeglumine: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Gadobenate Dimeglumine. Management: Consider alternatives to this 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

Gemifloxacin: May enhance the QTc-prolonging effect of QT-prolonging Class III Antiarrhythmics (Highest Risk). Avoid combination

Gilteritinib: May enhance the QTc-prolonging effect of QT-prolonging Agents (Highest Risk). Management: Consider alternatives to this combination. If use is necessary, monitor for QTc interval prolongation and arrhythmias. Consider therapy modification

Grapefruit Juice: May increase the serum concentration of Dronedarone. Avoid combination

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

Halofantrine: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Halofantrine. Management: Consider alternatives to this 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

Haloperidol: QT-prolonging Class III Antiarrhythmics (Highest Risk) may enhance the QTc-prolonging effect of Haloperidol. 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

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

Ibrutinib: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Ibrutinib. Management: When treating B-cell malignancies, decrease ibrutinib to 280 mg daily when combined with moderate CYP3A4 inhibitors. When treating graft versus host disease, monitor patients closely and reduce the ibrutinib dose as needed based on adverse reactions. Consider therapy modification

Idelalisib: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Avoid combination

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

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

Inotuzumab Ozogamicin: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Inotuzumab Ozogamicin. Management: Consider alternatives to this 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

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

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

Ivosidenib: May enhance the QTc-prolonging effect of Dronedarone. Dronedarone may increase the serum concentration of Ivosidenib. 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

Lacosamide: Bradycardia-Causing Agents may enhance the AV-blocking effect of Lacosamide. Monitor therapy

Lacosamide: Antiarrhythmic Agents (Class III) may enhance the adverse/toxic effect of Lacosamide. Specifically the risk for bradycardia, ventricular tachyarrhythmias, or a prolonged PR interval may be increased. Monitor therapy

Larotrectinib: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Monitor therapy

Larotrectinib: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Larotrectinib. Monitor therapy

Lefamulin: May enhance the QTc-prolonging effect of QT-prolonging CYP3A4 Substrates. Management: Do not use lefamulin tablets with QT-prolonging CYP3A4 substrates. Lefamulin prescribing information lists this combination as contraindicated. Avoid combination

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

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

Levofloxacin-Containing Products (Systemic): May enhance the QTc-prolonging effect of QT-prolonging Class III Antiarrhythmics (Highest Risk). Avoid combination

Lidocaine (Topical): May enhance the arrhythmogenic effect of Antiarrhythmic Agents (Class III). Antiarrhythmic Agents (Class III) may increase the serum concentration of Lidocaine (Topical). This mechanism specifically applies to amiodarone and dronedarone. Monitor therapy

Lofexidine: May enhance the QTc-prolonging effect of Dronedarone. Management: Consider alternatives to this combination. Patients with other risk factors (eg, older age, female sex, bradycardia, hypokalemia, hypomagnesemia, heart disease, and higher drug concentrations) are likely at greater risk for these toxicities. Consider therapy modification

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

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: Dronedarone may increase the serum concentration of Lovastatin. Management: Limit lovastatin to a maximum of 20 mg/day (in adults). Increase monitoring for signs of lovastatin toxicity (e.g., myopathy, rhabdomyolysis). Consider therapy modification

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

Lurasidone: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Lurasidone. Management: Lurasidone US labeling recommends reducing lurasidone dose by half with a moderate CYP3A4 inhibitor. Some non-US labeling recommends initiating lurasidone at 20 mg/day and limiting dose to 40 mg/day; avoid concurrent use of grapefruit products. Consider therapy modification

Manidipine: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Manidipine. Monitor therapy

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

Methadone: QT-prolonging Class III Antiarrhythmics (Highest Risk) may enhance the QTc-prolonging effect of Methadone. 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

Midodrine: May enhance the bradycardic effect of Bradycardia-Causing Agents. Monitor therapy

Midostaurin: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Midostaurin. Management: Consider alternatives to this 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

Mirodenafil: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Mirodenafil. Monitor therapy

Moxifloxacin (Systemic): QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Moxifloxacin (Systemic). Avoid combination

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

Naldemedine: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Naldemedine. Monitor therapy

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

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

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

Netupitant: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Monitor therapy

Nilotinib: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Nilotinib. Avoid combination

NiMODipine: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of NiMODipine. Monitor therapy

Nintedanib: Combined Inhibitors of CYP3A4 and P-glycoprotein may increase the serum concentration of Nintedanib. Monitor therapy

OLANZapine: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of OLANZapine. Management: Consider alternatives to this combination. Patients with other risk factors (eg, older age, female sex, bradycardia, hypokalemia, hypomagnesemia, heart disease, and higher drug concentrations) are likely at greater risk for these toxicities. Consider therapy modification

Olaparib: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Olaparib. Management: Avoid use of moderate 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 150 mg twice daily. Consider therapy modification

Ondansetron: QT-prolonging Class III Antiarrhythmics (Highest Risk) may enhance the QTc-prolonging effect of Ondansetron. Management: Consider alternatives to this 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

Osimertinib: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Osimertinib. Management: Consider alternatives to this combination. Patients with other risk factors (eg, older age, female sex, bradycardia, hypokalemia, hypomagnesemia, heart disease, and higher drug concentrations) are likely at greater risk for these toxicities. Consider therapy modification

OxyCODONE: CYP3A4 Inhibitors (Moderate) may enhance the adverse/toxic effect of OxyCODONE. CYP3A4 Inhibitors (Moderate) may increase the serum concentration of OxyCODONE. Serum concentrations of the active metabolite Oxymorphone may also be increased. Monitor therapy

Palbociclib: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Monitor therapy

PAZOPanib: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of PAZOPanib. Avoid combination

Pentamidine (Systemic): QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Pentamidine (Systemic). Management: Consider alternatives to this 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

Perhexiline: CYP2D6 Inhibitors (Weak) may increase the serum concentration of Perhexiline. Monitor therapy

Pexidartinib: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Pexidartinib. Monitor therapy

P-glycoprotein/ABCB1 Substrates: 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.). Exceptions: Loperamide. Monitor therapy

Pilsicainide: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Pilsicainide. Management: Consider alternatives to this 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

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

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

Pimozide: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Pimozide. Management: Consider alternatives to this combination. Patients with other risk factors (eg, older age, female sex, bradycardia, hypokalemia, hypomagnesemia, heart disease, and higher drug concentrations) are likely at greater risk for these toxicities. Avoid combination

Piperaquine: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Piperaquine. Avoid combination

Posaconazole: May increase the serum concentration of QT-prolonging CYP3A4 Substrates. Such increases may lead to a greater risk for proarrhythmic effects and other similar toxicities. Avoid combination

Probucol: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Probucol. Avoid combination

Propafenone: May enhance the QTc-prolonging effect 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. Consider therapy modification

Prucalopride: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Prucalopride. Monitor therapy

QT-prolonging Agents (Indeterminate Risk - Avoid): May enhance the QTc-prolonging effect of QT-prolonging Agents (Highest 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 Agents (Indeterminate Risk - Caution): May enhance the QTc-prolonging effect of QT-prolonging Agents (Highest 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 IA Antiarrhythmics (Highest Risk): May enhance the QTc-prolonging effect of QT-prolonging Class III Antiarrhythmics (Highest Risk). Avoid combination

QT-prolonging Class III Antiarrhythmics (Highest Risk): May enhance the QTc-prolonging effect of other QT-prolonging Class III Antiarrhythmics (Highest Risk). Avoid combination

QT-prolonging Kinase Inhibitors (Highest Risk): May enhance the QTc-prolonging effect of Dronedarone. 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): May enhance the QTc-prolonging effect of Dronedarone. 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: ChlorproMAZINE. Consider therapy modification

QT-prolonging Moderate CYP3A4 Inhibitors (Moderate Risk): May enhance the QTc-prolonging effect of Dronedarone. QT-prolonging Moderate CYP3A4 Inhibitors (Moderate Risk) may increase the serum concentration of Dronedarone. 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: Erythromycin (Systemic); Nilotinib; Ribociclib. Consider therapy modification

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

QUEtiapine: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of QUEtiapine. Avoid combination

Ranolazine: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Ranolazine. Management: Limit the ranolazine adult dose to a maximum of 500 mg twice daily in patients concurrently receiving moderate CYP3A4 inhibitors (e.g., diltiazem, verapamil, erythromycin, etc.). Consider therapy modification

Red Yeast Rice: Dronedarone may increase the serum concentration of Red Yeast Rice. In particular, concentrations of the lovastatin-like components may be increased. Monitor therapy

Ribociclib: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Ribociclib. Avoid combination

RifAXIMin: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of RifAXIMin. Monitor therapy

RisperiDONE: QT-prolonging Agents (Highest Risk) may enhance the CNS depressant effect of RisperiDONE. QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of RisperiDONE. 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

Rivaroxaban: Inhibitors of CYP3A4 (Moderate) and P-glycoprotein may increase the serum concentration of Rivaroxaban. Management: No action is needed in patients with normal renal function. US labeling recommends avoidance in patients with estimated creatinine clearance 15 to 80 mL/min unless prospective benefits outweigh the risks. Other non-US labels may differ. Consider therapy modification

Rosuvastatin: Dronedarone may increase the serum concentration of Rosuvastatin. Monitor therapy

Rupatadine: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Rupatadine. Monitor therapy

Ruxolitinib: May enhance the bradycardic effect of Bradycardia-Causing Agents. Management: Ruxolitinib Canadian product labeling recommends avoiding use with bradycardia-causing agents to the extent possible. Monitor therapy

Ruxolitinib: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Ruxolitinib. Monitor therapy

Salmeterol: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Salmeterol. Monitor therapy

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

SAXagliptin: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of SAXagliptin. Monitor therapy

Sildenafil: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Sildenafil. Monitor therapy

Silodosin: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Silodosin. Monitor therapy

Silodosin: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Silodosin. Monitor therapy

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

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

Simvastatin: Dronedarone may increase the serum concentration of Simvastatin. Management: Limit simvastatin to a max of 10 mg/day (in adults). Increase monitoring for signs of simvastatin toxicity (e.g., myositis, rhabdomyolysis). Consider therapy modification

Siponimod: Bradycardia-Causing Agents may enhance the bradycardic effect of Siponimod. Management: Avoid coadministration of siponimod with drugs that may cause bradycardia. Consider therapy modification

Sirolimus: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Sirolimus. Management: Monitor for increased serum concentrations of sirolimus if combined with a moderate CYP3A4 inhibitor. Lower initial sirolimus doses or sirolimus dose reductions will likely be required. Consider therapy modification

Sodium Stibogluconate: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Sodium Stibogluconate. Management: Consider alternatives to this 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

Sonidegib: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Sonidegib. Management: Avoid concomitant use of sonidegib and moderate CYP3A4 inhibitors when possible. When concomitant use cannot be avoided, limit CYP3A4 inhibitor use to less than 14 days and monitor for sonidegib toxicity (particularly musculoskeletal adverse reactions). Consider therapy modification

Sparfloxacin: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Sparfloxacin. Avoid combination

St John's Wort: May decrease the serum concentration of Dronedarone. Avoid combination

Stiripentol: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Management: Use of stiripentol with CYP3A4 substrates that are considered to have a narrow therapeutic index should be avoided due to the increased risk for adverse effects and toxicity. Any CYP3A4 substrate used with stiripentol requires closer monitoring. Consider therapy modification

Suvorexant: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Suvorexant. Management: The recommended dose of suvorexant is 5 mg daily in patients receiving a moderate CYP3A4 inhibitor. The dose can be increased to 10 mg daily (maximum dose) if necessary for efficacy. Consider therapy modification

Tacrolimus (Systemic): May enhance the QTc-prolonging effect of Dronedarone. Dronedarone may increase the serum concentration of Tacrolimus (Systemic). Management: Monitor for increased serum tacrolimus concentrations, tacrolimus toxicity, and QTc interval prolongation if combined with dronedarone. Tacrolimus dose adjustments may be needed. Consider therapy modification

Talazoparib: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Talazoparib. Management: These listed exceptions are discussed in detail in separate interaction monographs. Monitor therapy

Tamsulosin: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Tamsulosin. Monitor therapy

Tazemetostat: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Tazemetostat. Management: Avoid coadministration of tazemetostat and moderate CYP3A4 inhibitors. If coadministration cannot be avoided, dose reductions are required. See full monograph for dosing recommendations. Consider therapy modification

Tegaserod: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Tegaserod. Monitor therapy

Terlipressin: May enhance the bradycardic effect of Bradycardia-Causing Agents. Monitor therapy

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

Tezacaftor and Ivacaftor: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Tezacaftor and Ivacaftor. Management: When combined with moderate CYP3A4 inhibitors, tezacaftor/ivacaftor should be given in the morning, every other day. Ivacaftor alone should be given in the morning, every other day on alternate days. Consider therapy modification

Thioridazine: May enhance the QTc-prolonging effect of Dronedarone. Avoid combination

Ticagrelor: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Ticagrelor. Monitor therapy

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

Tofacitinib: May enhance the bradycardic effect of Bradycardia-Causing Agents. Monitor therapy

Tofacitinib: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Tofacitinib. Monitor therapy

Tolvaptan: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Tolvaptan. Management: Jynarque dose requires adjustment when used with a moderate CYP3A4 inhibitor. See labeling or full interaction monograph for specific recommendations. Use of Samsca with moderate CYP3A4 ihibitors should generally be avoided. Consider therapy modification

Topotecan: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Topotecan. Avoid combination

Trabectedin: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Trabectedin. Monitor therapy

Triazolam: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Triazolam. Management: Consider triazolam dose reduction in patients receiving concomitant moderate CYP3A4 inhibitors. Consider therapy modification

Tricyclic Antidepressants: May enhance the arrhythmogenic effect of Dronedarone. Management: Drugs listed as exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Exceptions: Doxepin (Systemic); Doxepin (Topical). Avoid combination

Ubrogepant: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Ubrogepant. Management: Use an initial ubrogepant dose of 50 mg and avoid a second dose for 24 hours when used with moderate CYP3A4 inhibitors. Consider therapy modification

Udenafil: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Udenafil. Monitor therapy

Ulipristal: CYP3A4 Inhibitors (Moderate) 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 combination should be monitored for ulipristal toxicity. Avoid combination

Vemurafenib: QT-prolonging Agents (Highest Risk) may enhance the QTc-prolonging effect of Vemurafenib. Management: Consider alternatives to this combination. Patients with other risk factors (eg, older age, female sex, bradycardia, hypokalemia, hypomagnesemia, heart disease, and higher drug concentrations) are likely at greater risk for these toxicities. Consider therapy modification

Venetoclax: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Venetoclax. Management: Reduce the venetoclax dose by at least 50% in patients requiring these combinations. Consider therapy modification

Venetoclax: P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Venetoclax. Management: Consider a venetoclax dose reduction by at least 50% in patients requiring concomitant treatment with P-glycoprotein (P-gp) inhibitors. Consider therapy modification

Vilazodone: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Vilazodone. Monitor therapy

VinCRIStine (Liposomal): P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of VinCRIStine (Liposomal). Avoid combination

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

Vitamin K Antagonists (eg, warfarin): Dronedarone may increase the serum concentration of Vitamin K Antagonists. Monitor therapy

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

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

Zuclopenthixol: CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Zuclopenthixol. Monitor therapy

Adverse Reactions

>10%:

Cardiovascular: Prolonged Q-T interval on ECG (Bazett; 28% [placebo: 19%]; defined as >450 msec in males or >470 msec in female)

Renal: Increased serum creatinine (51%; increased >10%; occurred 5 days after initiation)

1% to 10%:

Cardiovascular: Bradycardia (3%)

Dermatologic: Allergic dermatitis (≤5%), dermatitis (≤5%), eczema (≤5%), pruritus (≤5%), skin rash (≤5%; described as generalized, macular, maculopapular, erythematous)

Gastrointestinal: Diarrhea (9%), nausea (5%), abdominal pain (4%), dyspepsia (2%), vomiting (2%)

Neuromuscular & skeletal: Weakness (7%)

<1%, postmarketing, and/or case reports: Acute hepatic failure (requiring transplant), anaphylaxis, angioedema, atrial flutter (with 1:1 atrioventricular conduction), cardiac failure (new or worsened), dysgeusia, hepatic injury, hyperbilirubinemia, hypersensitivity angiitis, increased blood urea nitrogen, increased liver enzymes, interstitial pulmonary disease, pneumonitis, pulmonary fibrosis, skin photosensitivity, vasculitis

Warnings/Precautions

Concerns related to adverse effects:

• Heart failure (HF): New-onset or worsening HF symptoms have been observed. If patient develops new or worsening HF symptoms (eg, weight gain, dependent edema, or increasing shortness of breath) requiring hospitalization while on therapy, discontinue dronedarone.
• Hepatic effects: Severe liver injury, including acute liver failure leading to liver transplant, has been reported. If liver injury is suspected, discontinue therapy and evaluate liver enzymes/bilirubin. Appropriate treatment should be started and therapy should not be reinitiated if liver injury is confirmed. Advise patients to report any signs or symptoms of hepatic injury (anorexia, malaise, fatigue, jaundice, dark urine, itching, right upper quadrant pain, nausea, vomiting, abdominal pain, and/or fever). Consider periodic monitoring of serum liver enzymes and bilirubin, especially during the first 6 months of therapy.
• QT_c interval prolongation: Dronedarone induces a moderate prolongation of the QT interval (average ~10 msec); much greater effects have been observed. Use in patients with QT_c (Bazett) interval ≥500 msec is contraindicated; discontinue use of dronedarone if this occurs during therapy.
• Renal effects: Dronedarone may produce a slight increase in serum creatinine (~0.1 mg/dL) within 7 days of initiation due to inhibition of tubular secretion; glomerular filtration rate is not affected. Effect is reversible upon discontinuation. Marked increase in serum creatinine, prerenal azotemia and acute renal failure have been reported; usually in the setting of heart failure or hypovolemia. The effects appear to be reversible upon drug discontinuation and with appropriate medical treatment; monitor renal function periodically. Discontinue use in the setting of heart failure as this is a contraindication.
• Respiratory effects: Interstitial lung disease (including pulmonary fibrosis and pneumonitis) has been reported. Evaluate patients with onset of dyspnea or nonproductive cough for pulmonary toxicity. Discontinue therapy with confirmed pulmonary toxicity. Use is contraindicated in patients with previous pulmonary toxicity with amiodarone.

Disease-related concerns:

• Cardiac devices (eg, implanted defibrillators): One trial conducted during ischemia in a closed-chest animal (porcine) model demonstrated that dronedarone does not affect defibrillation threshold of implantable cardioverter defibrillators (ICD) compared to amiodarone (Chevalier 2012). However, prospective human studies are necessary to confirm these results in humans. Assess defibrillation threshold when initiating dronedarone and during therapy.
• Electrolyte imbalance: Correct electrolyte disturbances, especially hypokalemia or hypomagnesemia, prior to use and throughout therapy.
• Heart failure (HF): [US Boxed Warning]: The risk of death is doubled when used in patients with symptomatic HF with recent decompensation requiring hospitalization or NYHA Class IV symptoms; use is contraindicated in these patients. Canadian labeling contraindicates use of dronedarone in patients with a history of or current heart failure, regardless of NYHA class.
• Hepatic impairment: Use with caution in patients with mild to moderate hepatic impairment; use is contraindicated in severe hepatic impairment. Use is also contraindicated in patients with previous liver toxicity with amiodarone.
• Permanent atrial fibrillation (AF): [US Boxed Warning]: Use in patients with permanent atrial fibrillation doubles the risk of death, stroke (especially within the first 2 weeks of therapy), and hospitalization for heart failure. Use is contraindicated in patients with permanent AF who will not or cannot be converted to normal sinus rhythm. Monitor ECG at least every 3 months. Cardiovert patients who are in AF (if clinically indicated) or discontinue dronedarone.

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.

Special populations:

• Elderly: In the treatment of atrial fibrillation, avoid antiarrhythmics as first-line treatment. In older adults, data suggests rate control may provide more benefits than risks compared to rhythm control for most patients.
• Women of childbearing potential: Should use effective contraceptive methods during treatment.

Other warnings/precautions:

• Appropriate use: Initiate only in patients in sinus rhythm who are receiving appropriate antithrombotic therapy.

Monitoring Parameters

ECG (at least every 3 months), blood pressure, heart rate, and rhythm throughout therapy; assess patient for signs of new or worsening heart failure (eg, lethargy, breathlessness, edema of the hands or feet, weight gain) as well as liver injury (eg, jaundice, dark urine, anorexia, nausea, itching, fatigue, right upper quadrant pain, fever); monitor serum electrolytes (especially potassium and magnesium), periodically monitor serum liver enzymes and bilirubin (especially during the first 6 months of therapy)

Patients with implantable cardiac devices: Monitor pacing or defibrillation thresholds with initiation of dronedarone and during treatment.

Canadian labeling: Additional monitoring recommendations: ECG at least every 6 months during therapy; serum creatinine 1 week after initiating therapy followed by periodic renal function tests; periodic pulmonary function assessment

Pregnancy

Pregnancy Risk Factor

X

Pregnancy Considerations

Studies in animals have shown evidence of fetal abnormalities and use is contraindicated in women who are or may become pregnant.

Women of reproductive potential should use effective contraception during treatment.

Patient Education

What is this drug used for?

• It is used to treat certain types of abnormal heartbeats.

Frequently reported side effects of this drug

• Diarrhea
• Nausea
• Vomiting
• Loss of strength and energy
• Abdominal pain

Other side effects of this drug: Talk with your doctor right away if you have any of these signs of:

• Kidney problems like unable to pass urine, blood in the urine, change in amount of urine passed, or weight gain
• Heart problems like cough or shortness of breath that is new or worse, swelling of the ankles or legs, abnormal heartbeat, weight gain of more than five pounds in 24 hours, dizziness, or passing out
• Liver problems like dark urine, fatigue, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or yellow skin
• Severe pulmonary disorder like lung or breathing problems like difficulty breathing, shortness of breath, or a cough that is new or worse
• Dizziness
• Slow heartbeat
• Abnormal heartbeat
• Signs of a significant reaction like 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. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.