Imipramine

Dosage Forms

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

Capsule, Oral, as pamoate:

Generic: 75 mg, 100 mg, 125 mg, 150 mg

Tablet, Oral, as hydrochloride:

Tofranil: 10 mg [DSC], 25 mg [DSC], 50 mg [DSC]

Generic: 10 mg, 25 mg, 50 mg

Pharmacology

Mechanism of Action

Traditionally believed to increase the synaptic concentration of serotonin and/or norepinephrine in the central nervous system by inhibition of their reuptake by the presynaptic neuronal membrane. However, additional receptor effects have been found including desensitization of adenyl cyclase, down regulation of beta-adrenergic receptors, and down regulation of serotonin receptors.

Pharmacokinetics/Pharmacodynamics

Absorption

Well absorbed; not effected by food (Sallee 1990)

Distribution

V_d: Children: 14.5 L/kg; Adults: ~10 to 20 L/kg (Sallee 1990)

Metabolism

Hepatic, primarily via CYP2D6 to desipramine (active) and other metabolites; significant first-pass effect (Sallee 1990)

Excretion

Urine (as metabolites; <5% unchanged) (Salle 1990)

Onset of Action

Depression: Individual responses vary, however 4 to 8 weeks of treatment is needed before determining if a patient is partially or nonresponsive (APA 2010).

Time to Peak

Serum: 2 to 6 hours (Sallee 1990)

Half-Life Elimination

8 to 21 hours (Salle 1990); Mean: Children: 11 hours; Adults: 16 to 17 hours; Desipramine (active metabolite): 22 to 28 hours

Protein Binding

60% to 96%; primarily to alpha1 acid glycoprotein and lipoproteins; to a lesser extent albumin (Sallee 1990)

Use in Specific Populations

Special Populations: Elderly

Decreased clearance of imipramine and an increased elimination half-life may occur in elderly patients (Sallee 1990)

Special Populations Note

Alcohol use disorder: Increased clearance of imipramine and a decreased elimination half-life may occur in patients with alcohol use disorder

Cigarette smoking: Lower steady-state levels of imipramine and increased metabolism may occur in smokers (Sallee 1990)

Use: Labeled Indications

Childhood enuresis (imipramine hydrochloride only): As temporary adjunctive therapy in reducing enuresis in children ≥6 years of age, after possible organic causes have been excluded by appropriate tests

Major depressive disorder (unipolar): Treatment of unipolar major depressive disorder (MDD)

Use: Off Label

Bulimia nervosabyes

Data from double-blind placebo-controlled trials support the use of imipramine in the treatment of bulimia nervosa; however, all studies were limited by reliance on self-reporting of eating behavior.

The American Psychiatric Association guidelines for the treatment of patients with eating disorders indicate that tricyclic antidepressants may be a second-line option in patients who are at low risk for suicide. According to World Federation of Societies of Biological Psychiatry guidelines for the pharmacological treatment of eating disorders, imipramine is effective and recommended in the management of bulimia nervosa.

Neuropathic painbyes

Data from two randomized, double-blind, placebo-controlled, crossover trials Kvninesdal 1984, Sindrup 1998 and two randomized, double-blind, placebo-controlled, crossover trials with an active-comparator (paroxetine or venlafaxine) Sindrup 1990a, Sindrup 2003 support the use of imipramine in the treatment of neuropathic pain.

Based on the American Academy of Neurology (AAN) guidelines for the treatment of painful diabetic neuropathy, imipramine is not recommended because there is insufficient evidence to support use in this condition. Based on the International Association for the Study of Pain evidence-based recommendations for the treatment of neuropathic pain, the use of nortriptyline or desipramine is preferred over imipramine due to tolerability issues with imipramine IASP [Dworkin 2007].

Panic disorderbyes

Data from randomized, double-blind, placebo-controlled studies support the use of imipramine in the management of panic disorder with or without agoraphobia to decrease severity and frequency of panic attacks and prevent relapse Barlow 2000, Cross-National Collaborative Panic Study Investigators 1992, Mavissakalian 1999.

Based on the American Psychiatric Association practice guidelines for the treatment of patients with panic disorder, imipramine is an effective therapeutic option in the management of patients with panic disorder. Selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), and benzodiazepines have roughly comparable efficacy in the treatment of panic disorder, however, SSRIs are likely to have the most favorable balance of efficacy and adverse effects for most patients

Contraindications

Hypersensitivity to imipramine (cross-reactivity with other dibenzodiazepines may occur) or any component of the formulation; acute recovery period after a myocardial infarction (MI); use of MAO inhibitors intended to treat psychiatric disorders (concurrently or within 14 days of discontinuing either imipramine or the MAO inhibitor); initiation in patients receiving linezolid or methylene blue IV.

Documentation of allergenic cross-reactivity for tricyclic antidepressants is limited. However, because of similarities in chemical structure and/or pharmacologic actions, the possibility of cross-sensitivity cannot be ruled out with certainty.

Dosage and Administration

Dosing: Adult

Major depressive disorder (unipolar): Oral: Initial: 25 to 50 mg/day given in divided doses or as a single bedtime dose; may increase by 25 to 50 mg/day at intervals ≥1 week based on response and tolerability up to usual dose of 100 to 300 mg/day (APA 2010; Lecrubier 1997).

Manufacturer's labeling: Note: Dosing in the prescribing information may not reflect current clinical practice.

Outpatients: Initial: 75 mg/day; may increase gradually based on response and tolerability up to 200 mg/day; usual maintenance dose: 50 to 150 mg/day. May be given in divided doses or as a single bedtime dose.

Inpatients: Initial: 100 mg/day; may increase gradually based on response and tolerability to 200 mg/day; if no response after 2 weeks, may further increase to 250 to 300 mg/day. May be given in divided doses or as a single bedtime dose.

Bulimia nervosa (off-label use): Oral: Initial: 50 mg at bedtime; increase gradually based on response and tolerability up to 300 mg at bedtime (Agras 1987; Mitchell 1990; Pope 1983).

Neuropathic pain (off-label use): Oral: Note: Not the preferred TCA (Bril 2011; Dworkin 2007). Initial: 50 mg once daily or in divided doses twice daily; increase gradually up to 150 mg daily (Kvinesdal 1984; Sindrup 2003) or to a dosage sufficient to achieve an imipramine plus desipramine plasma concentration of 113 to 170 ng/mL (SI: 400 to 600 nmol/L) (Sindrup 1989; Sindrup 1990).

Panic disorder (off-label use): Oral: Initial: 10 mg/day; increase gradually over 3 to 5 weeks to a target dose of 100 to 300 mg/day; mean doses in studies ranged from 155 to 239 mg/day (APA [Stein 2009]; Barlow 2000; Cross-National Collaborative Panic Study 1992; WFSBP [Bandelow 2012]).

Discontinuation of therapy:When discontinuing antidepressant treatment that has lasted for >3 weeks, gradually taper the dose (eg, over 2 to 4 weeks) to minimize withdrawal symptoms and detect reemerging symptoms (APA 2010; WFSBP [Bauer 2015]). Reasons for a slower titration (eg, over 4 weeks) include use of a drug with a half-life <24 hours (eg, paroxetine, venlafaxine), prior history of antidepressant withdrawal symptoms, or high doses of antidepressants (APA 2010; Hirsch 2019). If intolerable withdrawal symptoms occur, resume the previously prescribed dose and/or decrease dose at a more gradual rate (Shelton 2001). Select patients (eg, those with a history of discontinuation syndrome) on long-term treatment (>6 months) may benefit from tapering over >3 months (WFSBP [Bauer 2015]). Evidence supporting ideal taper rates is limited (Shelton 2001; WFSBP [Bauer 2015]).

Switching antidepressants: Evidence for ideal antidepressant switching strategies is limited; strategies include cross-titration (gradually discontinuing the first antidepressant while at the same time gradually increasing the new antidepressant) and direct switch (abruptly discontinuing the first antidepressant and then starting the new antidepressant at an equivalent dose or lower dose and increasing it gradually). Cross-titration (eg, over 1 to 4 weeks depending upon sensitivity to discontinuation symptoms and adverse effects) is standard for most switches, but is contraindicated when switching to or from an MAO inhibitor. A direct switch may be an appropriate approach when switching to another agent in the same or similar class (eg, when switching between two SSRIs), when the antidepressant to be discontinued has been used for <1 week, or when the discontinuation is for adverse effects. When choosing the switch strategy, consider the risk of discontinuation symptoms, potential for drug interactions, other antidepressant properties (eg, half-life, adverse effects, and pharmacodynamics), and the degree of symptom control desired (Hirsch 2018; Ogle 2013; WFSBP [Bauer 2015]).

Switching to or from an MAOI:

Allow 14 days to elapse between discontinuing an MAOI and initiation of imipramine.

Allow 14 days to elapse between discontinuing imipramine and initiation of an MAOI.

Dosing: Geriatric

Major depressive disorder (MDD; unipolar): Initial: 10 to 25 mg at bedtime (Va/DoD 2016); refer to adult dosing.

Manufacturer's labeling: Dosing in the prescribing information may not reflect current clinical practice. Initial: 30 to 40 mg at bedtime; refer to adult manufacturer's dosing; usual dose: 100 mg/day.

Discontinuation of therapy: Refer to adult dosing.

Switching antidepressants: Refer to adult dosing.

Dosing: Pediatric

Note: Dosing presented is based on hydrochloride salt.

Attention-deficit/hyperactivity disorder: Limited data available: Children ≥6 years and Adolescents: Oral: Initial: 1 mg/kg/day in 1 to 3 divided doses; titrate as needed; maximum daily dose: 4 mg/kg/day or 200 mg/day; for doses >2 mg/kg/day, monitor serum concentrations (target: ≤200 ng/mL) (Himpel 2005; Pliszka 2007). Note: Manufacturer's labeling warns against use of doses >2.5 mg/kg/day in pediatric patients; ECG changes (of unknown significance) have been reported in pediatric patients who received twice this amount.

Depression: Limited data available: Oral: Note: Controlled clinical trials have not shown tricyclic antidepressants to be superior to placebo for the treatment of depression in children and adolescents; not recommended as first line medication; may be beneficial for patient with comorbid conditions (ADHD, enuresis) (AACAP [Birmaher 2007]; Dopheide 2006; Wagner 2005).

Children ≥8 years: 1.5 mg/kg/day in 2 to 3 divided doses; titrate as needed in increments of 1 mg/kg every 3 to 4 days; maximum daily doses of 5 mg/kg/day has been used by some centers; monitor carefully especially with doses ≥3.5 mg/kg/day; manufacturer's labeling warns against use of doses >2.5 mg/kg/day in pediatric patients; ECG changes (of unknown significance) have been reported in pediatric patients who received twice this amount (Dopheide 2006; Kliegman 2007)

Adolescents: Initial: 25 to 50 mg/day; increase gradually; maximum daily dose: 100 mg/day in single or divided doses

Enuresis: Children ≥6 years and Adolescents: Oral: Initial: 10 to 25 mg at bedtime (Kliegman 2007), if inadequate response still seen after 1 week of therapy, increase by 25 mg/day; maximum daily dose: The lesser of: 2.5 mg/kg/day or 50 mg/day if 6 to <12 years old; and 75 mg/day if ≥12 years old; for early night bedwetters, drug has been shown to be more effective if given earlier and in divided amounts (eg, 25 mg in midafternoon and repeated at bedtime). Although pharmacotherapy typically not used prior to 6 years of age, use in >4 years of age may be considered in some patients (Nelson 1996). Note: Due to the risk of serious side effects (eg, arrhythmias, heart block, seizures), imipramine is considered third-line treatment for enuresis (Deshpande 2012).

Discontinuation of therapy: Consider planning antidepressant discontinuation for lower-stress times, recognizing non-illness-related factors could cause stress or anxiety and be misattributed to antidepressant discontinuation (Hathaway 2018). Upon discontinuation of antidepressant therapy, gradually taper the dose to minimize the incidence of discontinuation syndromes (withdrawal) and allow for the detection of reemerging disease state symptoms (eg, relapse). Evidence supporting ideal taper rates after illness remission is limited. APA and NICE guidelines suggest tapering therapy over at least several weeks with consideration to the half-life of the antidepressant; antidepressants with a shorter half-life may need to be tapered more conservatively. After long-term (years) antidepressant treatment, WFSBP guidelines recommend tapering over 4 to 6 months, with close monitoring during and for 6 months after discontinuation. If intolerable discontinuation symptoms occur following a dose reduction, consider resuming the previously prescribed dose and/or decrease dose at a more gradual rate (APA 2010; Bauer 2002; Fenske 2009; Haddad 2001; NCCMH 2010; Schatzberg 2006; Shelton 2001; Warner 2006).

MAO inhibitor recommendations:

Switching to or from an MAO inhibitor intended to treat psychiatric disorders:

Allow 14 days to elapse between discontinuing an MAO inhibitor intended to treat psychiatric disorders and initiation of imipramine.

Allow 14 days to elapse between discontinuing imipramine and initiation of an MAO inhibitor intended to treat psychiatric disorders.

Storage

Capsules, tablets: Store between 20°C to 25°C (68°F to 77°F).

Drug Interactions

Abiraterone Acetate: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Management: Avoid concurrent use of abiraterone with CYP2D6 substrates that have a narrow therapeutic index whenever possible. When concurrent use is not avoidable, monitor patients closely for signs/symptoms of toxicity. Consider therapy modification

Acetylcholinesterase Inhibitors: May diminish the therapeutic effect of Anticholinergic Agents. Anticholinergic Agents may diminish the therapeutic effect of Acetylcholinesterase Inhibitors. Monitor therapy

Aclidinium: May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Ajmaline: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Alcohol (Ethyl): CNS Depressants may enhance the CNS depressant effect of Alcohol (Ethyl). Monitor therapy

Alfuzosin: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Alizapride: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Almotriptan: May enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Monitor therapy

Alosetron: May enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Monitor therapy

Alpha-/Beta-Agonists: Tricyclic Antidepressants may enhance the vasopressor effect of Alpha-/Beta-Agonists. Management: Avoid, if possible, the use of alpha-/beta-agonists in patients receiving tricyclic antidepressants. If combined, monitor for evidence of increased pressor effects and consider reductions in initial dosages of the alpha-/beta-agonist. Consider therapy modification

Alpha1-Agonists: Tricyclic Antidepressants may enhance the therapeutic effect of Alpha1-Agonists. Tricyclic Antidepressants may diminish the therapeutic effect of Alpha1-Agonists. Monitor therapy

Alpha2-Agonists: Tricyclic Antidepressants may diminish the antihypertensive effect of Alpha2-Agonists. Management: Consider avoiding this combination. If used, monitor for decreased effects of the alpha2-agonist. Exercise great caution if discontinuing an alpha2-agonist in a patient receiving a TCA. Exceptions: Apraclonidine; Brimonidine (Ophthalmic); Lofexidine. Consider therapy modification

Alpha2-Agonists (Ophthalmic): Tricyclic Antidepressants may diminish the therapeutic effect of Alpha2-Agonists (Ophthalmic). Monitor therapy

Altretamine: May enhance the orthostatic hypotensive effect of Tricyclic Antidepressants. Monitor therapy

Amantadine: May enhance the anticholinergic effect of Anticholinergic Agents. Monitor therapy

Amifampridine: Agents With Seizure Threshold Lowering Potential may enhance the neuroexcitatory and/or seizure-potentiating effect of Amifampridine. Monitor therapy

Amifostine: Blood Pressure Lowering Agents may enhance the hypotensive effect of Amifostine. Management: When amifostine is used at chemotherapy doses, blood pressure lowering medications should be withheld for 24 hours prior to amifostine administration. If blood pressure lowering therapy cannot be withheld, amifostine should not be administered. Consider therapy modification

Amphetamines: Tricyclic Antidepressants may enhance the adverse/toxic effect of Amphetamines. Tricyclic Antidepressants may potentiate the cardiovascular effects of Amphetamines. Amphetamines may enhance the serotonergic effect of Tricyclic Antidepressants. This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) and increased cardiovascular effects when these agents are combined. Monitor therapy

Anticholinergic Agents: May enhance the adverse/toxic effect of other Anticholinergic Agents. Monitor therapy

Antiemetics (5HT3 Antagonists): May enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Exceptions: Alosetron; Ondansetron; Ramosetron. Monitor therapy

Antipsychotic Agents: Serotonergic Agents (High Risk) may enhance the adverse/toxic effect of Antipsychotic Agents. Specifically, serotonergic agents may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotic Agents may enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Monitor therapy

Antipsychotic Agents (Second Generation [Atypical]): Blood Pressure Lowering Agents may enhance the hypotensive effect of Antipsychotic Agents (Second Generation [Atypical]). Monitor therapy

Aspirin: Tricyclic Antidepressants (Tertiary Amine) may enhance the antiplatelet effect of Aspirin. Monitor therapy

Asunaprevir: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Consider therapy modification

Azelastine (Nasal): CNS Depressants may enhance the CNS depressant effect of Azelastine (Nasal). Avoid combination

Barbiturates: May increase the metabolism of Tricyclic Antidepressants. Consider therapy modification

Benperidol: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Beta2-Agonists: Tricyclic Antidepressants may enhance the adverse/toxic effect of Beta2-Agonists. Monitor therapy

Blonanserin: CNS Depressants may enhance the CNS depressant effect of Blonanserin. Consider therapy modification

Blood Pressure Lowering Agents: May enhance the hypotensive effect of Hypotension-Associated Agents. Monitor therapy

Botulinum Toxin-Containing Products: May enhance the anticholinergic effect of Anticholinergic Agents. Monitor therapy

Brexanolone: CNS Depressants may enhance the CNS depressant effect of Brexanolone. Monitor therapy

Brimonidine (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Brimonidine (Topical): May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Bromopride: May enhance the adverse/toxic effect of Tricyclic Antidepressants. Avoid combination

Bromperidol: Blood Pressure Lowering Agents may enhance the hypotensive effect of Bromperidol. Bromperidol may diminish the hypotensive effect of Blood Pressure Lowering Agents. Avoid combination

Bromperidol: May enhance the CNS depressant effect of CNS Depressants. Avoid combination

Buprenorphine: CNS Depressants may enhance the CNS depressant effect of Buprenorphine. Management: Consider reduced doses of other CNS depressants, and avoiding such drugs in patients at high risk of buprenorphine overuse/self-injection. Initiate buprenorphine at lower doses in patients already receiving CNS depressants. Consider therapy modification

BusPIRone: May enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Monitor therapy

Cannabidiol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Cannabis: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

CarBAMazepine: May decrease the serum concentration of Tricyclic Antidepressants. Monitor therapy

Chloral Betaine: May enhance the adverse/toxic effect of Anticholinergic Agents. Monitor therapy

Chlormethiazole: May enhance the CNS depressant effect of CNS Depressants. Management: Monitor closely for evidence of excessive CNS depression. The chlormethiazole labeling states that an appropriately reduced dose should be used if such a combination must be used. Consider therapy modification

Chlorphenesin Carbamate: May enhance the adverse/toxic effect of CNS Depressants. Monitor therapy

Cimetidine: May decrease the metabolism of Tricyclic Antidepressants. Monitor therapy

Cimetropium: Anticholinergic Agents may enhance the anticholinergic effect of Cimetropium. Avoid combination

Cinacalcet: May increase the serum concentration of Tricyclic Antidepressants. Management: Seek alternatives when possible. If these combinations are used, monitor closely for increased effects/toxicity and/or elevated serum concentrations (when testing is available) of the tricyclic antidepressant. Consider therapy modification

Citalopram: Tricyclic Antidepressants may enhance the serotonergic effect of Citalopram. Tricyclic Antidepressants may increase the serum concentration of Citalopram. Citalopram may increase the serum concentration of Tricyclic Antidepressants. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) and increased TCA and citalopram concentrations/effects. Monitor therapy

CloBAZam: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

CNS Depressants: May enhance the adverse/toxic effect of other CNS Depressants. Monitor therapy

Cobicistat: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Cocaine (Topical): May enhance the adverse/toxic effect of Tricyclic Antidepressants. Monitor therapy

Cyclobenzaprine: May enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Monitor therapy

CYP2C19 Inducers (Moderate): May decrease the serum concentration of CYP2C19 Substrates (High risk with Inducers). Monitor therapy

CYP2C19 Inducers (Strong): May increase the metabolism of CYP2C19 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

CYP2D6 Inhibitors (Moderate): May decrease the metabolism of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

CYP2D6 Inhibitors (Strong): May decrease the metabolism of CYP2D6 Substrates (High risk with Inhibitors). Consider therapy modification

Dabrafenib: May decrease the serum concentration of CYP2C19 Substrates (High risk with Inducers). Management: Seek alternatives to the CYP2C19 substrate when possible. If concomitant therapy cannot be avoided, monitor clinical effects of the substrate closely (particularly therapeutic effects). Consider therapy modification

Dacomitinib: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Management: Avoid concurrent use of dacomitinib with CYP2D6 subtrates that have a narrow therapeutic index. Consider therapy modification

Dapoxetine: May enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Do not use serotonergic agents (high risk) with dapoxetine or within 7 days of serotonergic agent discontinuation. Do not use dapoxetine within 14 days of monoamine oxidase inhibitor use. Dapoxetine labeling lists this combination as contraindicated. Avoid combination

Darunavir: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Desmopressin: Tricyclic Antidepressants may enhance the adverse/toxic effect of Desmopressin. Monitor therapy

Dexmethylphenidate-Methylphenidate: May enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Monitor therapy

Dextromethorphan: May enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Monitor therapy

Diazoxide: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Dimethindene (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Doxylamine: May enhance the CNS depressant effect of CNS Depressants. Management: The manufacturer of Diclegis (doxylamine/pyridoxine), intended for use in pregnancy, specifically states that use with other CNS depressants is not recommended. Monitor therapy

Dronabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Dronedarone: 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. Avoid combination

Droperidol: May enhance the CNS depressant effect of CNS Depressants. Management: Consider dose reductions of droperidol or of other CNS agents (eg, opioids, barbiturates) with concomitant use. Exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Consider therapy modification

DULoxetine: May enhance the serotonergic effect of Tricyclic Antidepressants. This could result in serotonin syndrome. DULoxetine may increase the serum concentration of Tricyclic Antidepressants. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) and increased TCA concentrations and effects if these agents are combined. Monitor therapy

DULoxetine: Blood Pressure Lowering Agents may enhance the hypotensive effect of DULoxetine. Monitor therapy

Eletriptan: May enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Monitor therapy

Eluxadoline: Anticholinergic Agents may enhance the constipating effect of Eluxadoline. Avoid combination

Enzalutamide: May decrease the serum concentration of CYP2C19 Substrates (High risk with Inducers). Conversely, concentrations of active metabolites may be increased for those drugs activated by CYP2C19. Management: Concurrent use of enzalutamide with CYP2C19 substrates that have a narrow therapeutic index should be avoided. Use of enzalutamide and any other CYP2C19 substrate should be performed with caution and close monitoring. Consider therapy modification

Ergot Derivatives: May enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Exceptions: Nicergoline. Monitor therapy

Escitalopram: Tricyclic Antidepressants may enhance the serotonergic effect of Escitalopram. Escitalopram may increase the serum concentration of Tricyclic Antidepressants. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) and increased TCA concentrations/effects if these agents are combined. Monitor therapy

Esketamine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Fexinidazole [INT]: Tricyclic Antidepressants may enhance the QTc-prolonging effect of Fexinidazole [INT]. Avoid combination

Flunitrazepam: CNS Depressants may enhance the CNS depressant effect of Flunitrazepam. Consider therapy modification

FLUoxetine: May enhance the serotonergic effect of Tricyclic Antidepressants. FLUoxetine may increase the serum concentration of Tricyclic Antidepressants. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) and increased TCA concentrations/effects if these agents are combined. Consider therapy modification

FluvoxaMINE: May enhance the serotonergic effect of Tricyclic Antidepressants. FluvoxaMINE may increase the serum concentration of Tricyclic Antidepressants. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) and increased TCA concentrations/effects if these agents are combined. Monitor therapy

Gastrointestinal Agents (Prokinetic): Anticholinergic Agents may diminish the therapeutic effect of Gastrointestinal Agents (Prokinetic). Monitor therapy

Glucagon: Anticholinergic Agents may enhance the adverse/toxic effect of Glucagon. Specifically, the risk of gastrointestinal adverse effects may be increased. Monitor therapy

Glycopyrrolate (Oral Inhalation): Anticholinergic Agents may enhance the anticholinergic effect of Glycopyrrolate (Oral Inhalation). Avoid combination

Glycopyrronium (Topical): May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Guanethidine: Tricyclic Antidepressants may diminish the therapeutic effect of Guanethidine. Monitor therapy

Herbs (Hypotensive Properties): May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

HYDROcodone: CNS Depressants may enhance the CNS depressant effect of HYDROcodone. Management: Avoid concomitant use of hydrocodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

HydrOXYzine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Hypotension-Associated Agents: Blood Pressure Lowering Agents may enhance the hypotensive effect of Hypotension-Associated Agents. Monitor therapy

Imatinib: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Iobenguane Radiopharmaceutical Products: Tricyclic Antidepressants may diminish the therapeutic effect of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer these drugs until at least 7 days after each iobenguane dose. Avoid combination

Iohexol: Agents With Seizure Threshold Lowering Potential may enhance the adverse/toxic effect of Iohexol. Specifically, the risk for seizures may be increased. Management: Discontinue agents that may lower the seizure threshold 48 hours prior to intrathecal use of iohexol. Wait at least 24 hours after the procedure to resume such agents. In nonelective procedures, consider use of prophylactic anticonvulsants. Consider therapy modification

Iomeprol: Agents With Seizure Threshold Lowering Potential may enhance the adverse/toxic effect of Iomeprol. Specifically, the risk for seizures may be increased. Management: Discontinue agents that may lower the seizure threshold 48 hours prior to intrathecal use of iomeprol. Wait at least 24 hours after the procedure to resume such agents. In nonelective procedures, consider use of prophylactic anticonvulsants. Consider therapy modification

Iopamidol: Agents With Seizure Threshold Lowering Potential may enhance the adverse/toxic effect of Iopamidol. Specifically, the risk for seizures may be increased. Management: Discontinue agents that may lower the seizure threshold 48 hours prior to intrathecal use of iopamidol. Wait at least 24 hours after the procedure to resume such agents. In nonelective procedures, consider use of prophylactic anticonvulsants. Consider therapy modification

Ipratropium (Oral Inhalation): May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Itopride: Anticholinergic Agents may diminish the therapeutic effect of Itopride. Monitor therapy

Kava Kava: May enhance the adverse/toxic effect of CNS Depressants. Monitor therapy

Lasmiditan: May enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Monitor therapy

Lemborexant: May enhance the CNS depressant effect of CNS Depressants. Management: Dosage adjustments of lemborexant and of concomitant CNS depressants may be necessary when administered together because of potentially additive CNS depressant effects. Close monitoring for CNS depressant effects is necessary. Consider therapy modification

Levodopa-Containing Products: Blood Pressure Lowering Agents may enhance the hypotensive effect of Levodopa-Containing Products. Monitor therapy

Levosulpiride: Anticholinergic Agents may diminish the therapeutic effect of Levosulpiride. Avoid combination

Linezolid: May enhance the serotonergic effect of Tricyclic Antidepressants. This could result in serotonin syndrome. Avoid combination

Lofexidine: Tricyclic Antidepressants may diminish the therapeutic effect of Lofexidine. Management: Consider avoiding this drug combination when possible. If concurrent administration is required, monitor blood pressure carefully at the beginning of the combined therapy and when either drug is stopped. Adjust the dosage accordingly. Consider therapy modification

Lorcaserin: May enhance the serotonergic effect of Tricyclic Antidepressants. This could result in serotonin syndrome. Lorcaserin may increase the serum concentration of Tricyclic Antidepressants. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) and increased TCA concentrations and effects if these agents are combined. Monitor therapy

Lormetazepam: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Lumacaftor and Ivacaftor: May decrease the serum concentration of CYP2C19 Substrates (High risk with Inducers). Monitor therapy

Lumefantrine: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Magnesium Sulfate: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Melatonin: May enhance the adverse/toxic effect of Imipramine. Monitor therapy

Metaxalone: May enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Monitor therapy

Methotrimeprazine: CNS Depressants may enhance the CNS depressant effect of Methotrimeprazine. Methotrimeprazine may enhance the CNS depressant effect of CNS Depressants. Management: Reduce adult dose of CNS depressant agents by 50% with initiation of concomitant methotrimeprazine therapy. Further CNS depressant dosage adjustments should be initiated only after clinically effective methotrimeprazine dose is established. Consider therapy modification

Methylene Blue: Tricyclic Antidepressants may enhance the serotonergic effect of Methylene Blue. This could result in serotonin syndrome. Avoid combination

Metoclopramide: May enhance the adverse/toxic effect of Tricyclic Antidepressants. Management: Seek alternatives to this combination when possible. Monitor patients receiving metoclopramide with tricyclic antidepressants for signs of extrapyramidal symptoms, neuroleptic malignant syndrome, and serotonin syndrome. Consider therapy modification

MetyroSINE: CNS Depressants may enhance the sedative effect of MetyroSINE. Monitor therapy

MetyroSINE: May enhance the adverse/toxic effect of Tricyclic Antidepressants. Monitor therapy

Mianserin: May enhance the anticholinergic effect of Anticholinergic Agents. Monitor therapy

Minocycline (Systemic): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Mirabegron: Anticholinergic Agents may enhance the adverse/toxic effect of Mirabegron. Monitor therapy

Molsidomine: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Monoamine Oxidase Inhibitors (Antidepressant): May enhance the serotonergic effect of Tricyclic Antidepressants. This could result in serotonin syndrome. Avoid combination

Nabilone: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Naftopidil: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Nefazodone: Tricyclic Antidepressants may enhance the serotonergic effect of Nefazodone. This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Monitor therapy

Nicergoline: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Nicorandil: Tricyclic Antidepressants may enhance the hypotensive effect of Nicorandil. Monitor therapy

Nicorandil: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Nitroglycerin: Anticholinergic Agents may decrease the absorption of Nitroglycerin. Specifically, anticholinergic agents may decrease the dissolution of sublingual nitroglycerin tablets, possibly impairing or slowing nitroglycerin absorption. Monitor therapy

Nitroprusside: Blood Pressure Lowering Agents may enhance the hypotensive effect of Nitroprusside. Monitor therapy

Nonsteroidal Anti-Inflammatory Agents (COX-2 Selective): Tricyclic Antidepressants (Tertiary Amine) may enhance the antiplatelet effect of Nonsteroidal Anti-Inflammatory Agents (COX-2 Selective). Monitor therapy

Nonsteroidal Anti-Inflammatory Agents (Nonselective): Tricyclic Antidepressants (Tertiary Amine) may enhance the antiplatelet effect of Nonsteroidal Anti-Inflammatory Agents (Nonselective). Monitor therapy

Obinutuzumab: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Management: Consider temporarily withholding blood pressure lowering medications beginning 12 hours prior to obinutuzumab infusion and continuing until 1 hour after the end of the infusion. Consider therapy modification

Ondansetron: May enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Monitor therapy

Opioid Agonists: CNS Depressants may enhance the CNS depressant effect of Opioid Agonists. Management: Avoid concomitant use of opioid agonists and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

Orphenadrine: CNS Depressants may enhance the CNS depressant effect of Orphenadrine. Avoid combination

Oxatomide: May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Oxitriptan: Serotonergic Agents (High Risk) may enhance the serotonergic effect of Oxitriptan. This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Monitor therapy

Oxomemazine: May enhance the CNS depressant effect of CNS Depressants. Avoid combination

OxyCODONE: CNS Depressants may enhance the CNS depressant effect of OxyCODONE. Management: Avoid concomitant use of oxycodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

Panobinostat: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Paraldehyde: CNS Depressants may enhance the CNS depressant effect of Paraldehyde. Avoid combination

PARoxetine: May enhance the serotonergic effect of Tricyclic Antidepressants. PARoxetine may increase the serum concentration of Tricyclic Antidepressants. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) and increased TCA concentrations/effects if these agents are combined. Consider therapy modification

Peginterferon Alfa-2b: May decrease the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Peginterferon Alfa-2b may increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Pentoxifylline: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Perampanel: May enhance the CNS depressant effect of CNS Depressants. Management: Patients taking perampanel with any other drug that has CNS depressant activities should avoid complex and high-risk activities, particularly those such as driving that require alertness and coordination, until they have experience using the combination. Consider therapy modification

Perhexiline: CYP2D6 Substrates (High risk with Inhibitors) may increase the serum concentration of Perhexiline. Perhexiline may increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Pholcodine: Blood Pressure Lowering Agents may enhance the hypotensive effect of Pholcodine. Monitor therapy

Phosphodiesterase 5 Inhibitors: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Piribedil: CNS Depressants may enhance the CNS depressant effect of Piribedil. Monitor therapy

Pitolisant: Tricyclic Antidepressants may diminish the therapeutic effect of Pitolisant. Avoid combination

Potassium Chloride: Anticholinergic Agents may enhance the ulcerogenic effect of Potassium Chloride. Management: Patients on drugs with substantial anticholinergic effects should avoid using any solid oral dosage form of potassium chloride. Avoid combination

Potassium Citrate: Anticholinergic Agents may enhance the ulcerogenic effect of Potassium Citrate. Avoid combination

Pramipexole: CNS Depressants may enhance the sedative effect of Pramipexole. Monitor therapy

Pramlintide: May enhance the anticholinergic effect of Anticholinergic Agents. These effects are specific to the GI tract. Consider therapy modification

Prostacyclin Analogues: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

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

Quinagolide: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

QuiNIDine: Tricyclic Antidepressants may enhance the QTc-prolonging effect of QuiNIDine. QuiNIDine may increase the serum concentration of Tricyclic Antidepressants. Management: Drugs listed as exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Consider therapy modification

QuiNINE: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Ramosetron: Anticholinergic Agents may enhance the constipating effect of Ramosetron. Monitor therapy

Ramosetron: May enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Monitor therapy

Rasagiline: May enhance the serotonergic effect of Tricyclic Antidepressants. This could result in serotonin syndrome. Avoid combination

Revefenacin: Anticholinergic Agents may enhance the anticholinergic effect of Revefenacin. Avoid combination

ROPINIRole: CNS Depressants may enhance the sedative effect of ROPINIRole. Monitor therapy

Rotigotine: CNS Depressants may enhance the sedative effect of Rotigotine. Monitor therapy

Rufinamide: May enhance the adverse/toxic effect of CNS Depressants. Specifically, sleepiness and dizziness may be enhanced. Monitor therapy

Safinamide: May enhance the serotonergic effect of Tricyclic Antidepressants. This could result in serotonin syndrome. Avoid combination

Secretin: Anticholinergic Agents may diminish the therapeutic effect of Secretin. Management: Avoid concomitant use of anticholinergic agents and secretin. Discontinue anticholinergic agents at least 5 half-lives prior to administration of secretin. Consider therapy modification

Selegiline: May enhance the serotonergic effect of Imipramine. This could result in serotonin syndrome. Avoid combination

Serotonergic Agents (High Risk, Miscellaneous): Tricyclic Antidepressants may enhance the serotonergic effect of Serotonergic Agents (High Risk, Miscellaneous). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Monitor therapy

Serotonergic Non-Opioid CNS Depressants: Tricyclic Antidepressants may enhance the CNS depressant effect of Serotonergic Non-Opioid CNS Depressants. Tricyclic Antidepressants may enhance the serotonergic effect of Serotonergic Non-Opioid CNS Depressants. This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) and CNS depression when these agents are combined. Monitor therapy

Serotonergic Opioids (High Risk): Tricyclic Antidepressants may enhance the CNS depressant effect of Serotonergic Opioids (High Risk). Serotonergic Opioids (High Risk) may enhance the serotonergic effect of Tricyclic Antidepressants. This could result in serotonin syndrome. Management: Consider alternatives to this drug combination. If combined, monitor for signs and symptoms of serotonin syndrome/serotonin toxicity and CNS depression. Consider therapy modification

Serotonin 5-HT1D Receptor Agonists (Triptans): May enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Exceptions: Almotriptan; Eletriptan. Monitor therapy

Serotonin/Norepinephrine Reuptake Inhibitors: May enhance the serotonergic effect of Tricyclic Antidepressants. This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes when these agents are combined. Exceptions: DULoxetine. Monitor therapy

Sertraline: May enhance the serotonergic effect of Tricyclic Antidepressants. Sertraline may increase the serum concentration of Tricyclic Antidepressants. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) and increased TCA concentrations/effects if these agents are combined. Monitor therapy

Sodium Oxybate: May enhance the CNS depressant effect of CNS Depressants. Management: Consider alternatives to combined use. When combined use is needed, consider minimizing doses of one or more drugs. Use of sodium oxybate with alcohol or sedative hypnotics is contraindicated. Consider therapy modification

Sodium Phosphates: Tricyclic Antidepressants may enhance the adverse/toxic effect of Sodium Phosphates. Specifically, the risk of seizure and/or loss of consciousness may be increased in patients with significant sodium phosphate induced fluid/electrolyte abnormalities. Monitor therapy

St John's Wort: May enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. St John's Wort may decrease the serum concentration of Serotonergic Agents (High Risk). Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Monitor therapy

Sulfonylureas: Cyclic Antidepressants may enhance the hypoglycemic effect of Sulfonylureas. Monitor therapy

Suvorexant: CNS Depressants may enhance the CNS depressant effect of Suvorexant. Management: Dose reduction of suvorexant and/or any other CNS depressant may be necessary. Use of suvorexant with alcohol is not recommended, and the use of suvorexant with any other drug to treat insomnia is not recommended. Consider therapy modification

Syrian Rue: May enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Monitor therapy

Tapentadol: May enhance the CNS depressant effect of CNS Depressants. Management: Avoid concomitant use of tapentadol and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

Terbinafine (Systemic): May increase the serum concentration of Imipramine. Management: Monitor for increased effects/toxicity of imipramine during concomitant administration with terbinafine. Reduced dosages of imipramine may be needed. Consider therapy modification

Tetrahydrocannabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Tetrahydrocannabinol and Cannabidiol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Thalidomide: CNS Depressants may enhance the CNS depressant effect of Thalidomide. Avoid combination

Thiazide and Thiazide-Like Diuretics: Anticholinergic Agents may increase the serum concentration of Thiazide and Thiazide-Like Diuretics. Monitor therapy

Thyroid Products: May enhance the arrhythmogenic effect of Tricyclic Antidepressants. Thyroid Products may enhance the stimulatory effect of Tricyclic Antidepressants. Monitor therapy

Tiotropium: Anticholinergic Agents may enhance the anticholinergic effect of Tiotropium. Avoid combination

Tobacco (Smoked): May decrease the serum concentration of Imipramine. Monitor therapy

Topiramate: Anticholinergic Agents may enhance the adverse/toxic effect of Topiramate. Monitor therapy

Tricyclic Antidepressants: May enhance the anticholinergic effect of other Tricyclic Antidepressants. Tricyclic Antidepressants may enhance the CNS depressant effect of other Tricyclic Antidepressants. Tricyclic Antidepressants may enhance the serotonergic effect of other Tricyclic Antidepressants. This could result in serotonin syndrome. Management: Monitor closely for increased TCA adverse effects, including serotonin syndrome/serotonin toxicity, CNS depression, and anticholinergic effects. Monitor therapy

Trimeprazine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Umeclidinium: May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Valproate Products: May increase the serum concentration of Tricyclic Antidepressants. Monitor therapy

Vilazodone: Tricyclic Antidepressants may enhance the serotonergic effect of Vilazodone. This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) if these agents are combined. Monitor therapy

Vitamin K Antagonists (eg, warfarin): Tricyclic Antidepressants may enhance the anticoagulant effect of Vitamin K Antagonists. Monitor therapy

Vortioxetine: Tricyclic Antidepressants may enhance the serotonergic effect of Vortioxetine. This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) if these agents are combined. Monitor therapy

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

Zolpidem: CNS Depressants may enhance the CNS depressant effect of Zolpidem. Management: Reduce the Intermezzo brand sublingual zolpidem adult dose to 1.75 mg for men who are also receiving other CNS depressants. No such dose change is recommended for women. Avoid use with other CNS depressants at bedtime; avoid use with alcohol. Consider therapy modification

Adverse Reactions

Reported for tricyclic antidepressants in general. Frequency not defined.

Cardiovascular: Cardiac arrhythmia, cardiac failure, cerebrovascular accident, ECG changes, heart block, hypertension, myocardial infarction, orthostatic hypotension, palpitations, tachycardia

Central nervous system: Agitation, anxiety, ataxia, confusion, delusions, disorientation, dizziness, drowsiness, EEG pattern changes, extrapyramidal reaction, falling, fatigue, hallucination, headache, hypomania, insomnia, nightmares, numbness, paresthesia, peripheral neuropathy, psychosis, restlessness, seizure, taste disorder, tingling sensation

Dermatologic: Alopecia, diaphoresis, pruritus, skin photosensitivity, skin rash, urticaria

Endocrine & metabolic: Decreased libido, decreased serum glucose, galactorrhea, gynecomastia, increased libido, increased serum glucose, SIADH, weight gain, weight loss

Gastrointestinal: Abdominal cramps, anorexia, constipation, diarrhea, epigastric distress, intestinal obstruction, melanoglossia, nausea, stomatitis, sublingual adenitis, vomiting, xerostomia

Genitourinary: Breast hypertrophy, impotence, testicular swelling, urinary hesitancy, urinary retention, urinary tract dilation

Hematologic & oncologic: Agranulocytosis, eosinophilia, petechia, purpura, thrombocytopenia

Hepatic: Cholestatic jaundice, increased serum transaminases

Hypersensitivity: Hypersensitivity (eg, drug fever, edema)

Neuromuscular & skeletal: Tremor, weakness

Ophthalmic: Accommodation disturbance, angle-closure glaucoma, blurred vision, mydriasis

Otic: Tinnitus

Warnings/Precautions

Major psychiatric warnings:

• Suicidal thinking/behavior: [US Boxed Warning]: Antidepressants increase the risk of suicidal thinking and behavior in children, adolescents, and young adults (18 to 24 years of age) with major depressive disorder (MDD) and other psychiatric disorders; consider risk prior to prescribing. Short-term studies did not show an increased risk in patients >24 years of age and showed a decreased risk in patients ≥65 years. Closely monitor patients for clinical worsening, suicidality, or unusual changes in behavior, particularly during the initial 1 to 2 months of therapy or during periods of dosage adjustments (increases or decreases); the patient's family or caregiver should be instructed to closely observe the patient and communicate condition with healthcare provider. A medication guide concerning the use of antidepressants should be dispensed with each prescription. Imipramine is FDA approved for the treatment of nocturnal enuresis in children ≥6 years of age.
• The possibility of a suicide attempt is inherent in major depression and may persist until remission occurs. Worsening depression and severe abrupt suicidality that are not part of the presenting symptoms may require discontinuation or modification of drug therapy. Use caution in high-risk patients during initiation of therapy.
• Prescriptions should be written for the smallest quantity consistent with good patient care. The patient's family or caregiver should be alerted to monitor patients for the emergence of suicidality and associated behaviors such as anxiety, agitation, panic attacks, insomnia, irritability, hostility, impulsivity, akathisia, hypomania, and mania; patients should be instructed to notify their healthcare provider if any of these symptoms or worsening depression or psychosis occur.

Concerns related to adverse effects:

• Anticholinergic effects: May cause anticholinergic effects (constipation, xerostomia, blurred vision, urinary retention); use with caution in patients with decreased gastrointestinal motility, increased intraocular pressure, angle-closure glaucoma, paralytic ileus, urinary retention, BPH, xerostomia, or visual problems. The degree of anticholinergic blockade produced by this agent is high relative to other antidepressants.
• CNS depression: May cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks that require mental alertness (eg, operating machinery or driving). The degree of sedation is high relative to other antidepressants.
• Fractures: Bone fractures have been associated with antidepressant treatment. Consider the possibility of a fragility fracture if an antidepressant-treated patient presents with unexplained bone pain, point tenderness, swelling, or bruising (Rabenda 2013; Rizzoli 2012).
• Hematologic effects: TCAs may rarely cause bone marrow suppression; monitor for any signs of infection and obtain CBC if symptoms (eg, fever, sore throat) are evident. Discontinue imipramine if there is evidence of pathological neutrophil depression.
• Orthostatic hypotension: May cause orthostatic hypotension (risk is very high relative to other antidepressants); use with caution in patients at risk of this effect or in those who would not tolerate transient hypotensive episodes (cerebrovascular disease, cardiovascular disease, hypovolemia, or concurrent medication use which may predispose to hypotension/bradycardia).
• Photosensitization: Has been associated with photosensitization; avoid excessive exposure to sunlight.
• Serotonin syndrome: Potentially life-threatening serotonin syndrome (SS) has occurred with serotonergic agents (eg, SSRIs, SNRIs), particularly when used in combination with other serotonergic agents (eg, triptans, TCAs, fentanyl, lithium, tramadol, buspirone, St John's wort, tryptophan) or agents that impair metabolism of serotonin (eg, MAO inhibitors intended to treat psychiatric disorders, other MAO inhibitors [ie, linezolid and intravenous methylene blue]). Monitor patients closely for signs of SS such as mental status changes (eg, agitation, hallucinations, delirium, coma); autonomic instability (eg, tachycardia, labile blood pressure, diaphoresis); neuromuscular changes (eg, tremor, rigidity, myoclonus); GI symptoms (eg, nausea, vomiting, diarrhea); and/or seizures. Discontinue treatment (and any concomitant serotonergic agent) immediately if signs/symptoms arise.

Disease-related concerns:

• Alcohol use disorder: Pharmacokinetics of imipramine may be altered in patients with chronic alcohol use disorder; increased clearance and a decreased elimination half-life have been reported (Sallee 1990).
• Cardiovascular disease: Use with caution in patients with a history of cardiovascular disease (including previous MI, stroke, tachycardia, or conduction abnormalities); the risk of conduction abnormalities with this agent is high relative to other antidepressants. In a scientific statement from the American Heart Association, imipramine has been determined to be an agent that may exacerbate underlying myocardial dysfunction (magnitude: moderate) (AHA [Page 2016]). Baseline and periodic assessment of EKG is recommended with use of higher dosages, and should also be considered in elderly patients and/or patients with preexisting cardiovascular disease.
• Diabetes: Use with caution in patients with diabetes mellitus; may alter glucose regulation.
• Hepatic impairment: Use with caution in patients with hepatic impairment.
• Mania/hypomania: May worsen psychosis in some patients or precipitate a shift to mania or hypomania in patients with bipolar disorder. Monotherapy in patients with bipolar disorder should be avoided. Patients presenting with depressive symptoms should be screened for bipolar disorder. Imipramine is not FDA approved for the treatment of bipolar depression.
• Ocular effects: May cause mild pupillary dilation which in susceptible individuals can lead to an episode of narrow-angle glaucoma. Consider evaluating patients who have not had an iridectomy for narrow-angle glaucoma risk factors.
• Renal impairment: Use with caution in patients with renal impairment.
• Seizure disorder: Use with caution in patients at risk of seizures, including those with a history of seizures, head trauma, brain damage, alcoholism, or concurrent therapy with medications which may lower seizure threshold.

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:

• Children: A dose of 2.5 mg/kg/day of imipramine hydrochloride should not be exceeded in childhood. ECG changes of unknown significance have been reported in pediatric patients with doses twice this amount.
• Elderly: Lower doses may be required in geriatric patients due to pharmacokinetic changes.
• Smokers: Imipramine levels may be lower in patients who smoke (Sallee 1990).

Dosage form specific issues:

• Tartrazine: Some formulations may contain tartrazine (FD&C Yellow No. 5) which may cause allergic-type reactions (including bronchial asthma) in susceptible individuals, particularly those who also have aspirin sensitivity.

Other warnings/precautions:

• Discontinuation syndrome: Abrupt discontinuation or interruption of antidepressant therapy has been associated with a discontinuation syndrome. Symptoms arising may vary with antidepressant however commonly include nausea, vomiting, diarrhea, headaches, light-headedness, dizziness, diminished appetite, sweating, chills, tremors, paresthesias, fatigue, somnolence, and sleep disturbances (eg, vivid dreams, insomnia). Less common symptoms include electric shock-like sensations, cardiac arrhythmias (more common with tricyclic antidepressants), myalgias, parkinsonism, arthralgias, and balance difficulties. Psychological symptoms may also emerge such as agitation, anxiety, akathisia, panic attacks, irritability, aggressiveness, worsening of mood, dysphoria, mood lability, hyperactivity, mania/hypomania, depersonalization, decreased concentration, slowed thinking, confusion, and memory or concentration difficulties. Greater risks for developing a discontinuation syndrome have been associated with antidepressants with shorter half-lives, longer durations of treatment, and abrupt discontinuation. For antidepressants of short or intermediate half-lives, symptoms may emerge within 2 to 5 days after treatment discontinuation and last 7 to 14 days (APA 2010; Fava 2006; Haddod 2001; Shelton 2001; Warner 2006).
• Electroconvulsive therapy: May increase the risks associated with electroconvulsive therapy; consider discontinuing, when possible, prior to ECT treatment.
• Surgery: Recommended by the manufacturer to discontinue prior to elective surgery; risks exist for drug interactions with anesthesia and for cardiac arrhythmias. However, definitive drug interactions have not been widely reported in the literature and continuation of tricyclic antidepressants is generally recommended as long as precautions are taken to reduce the significance of any adverse events that may occur. Norepinephrine should be considered the vasopressor of choice for TCA-related hypotension (Pass 2004). Therapy should not be abruptly discontinued in patients receiving high doses for prolonged periods.

Monitoring Parameters

CBC, ECG (baseline and with dose increases) in older adults, with high doses, and/or in patients with preexisting cardiovascular disease; monitor blood pressure and pulse rate prior to and during initial therapy; serum sodium in at-risk populations (as clinically indicated); evaluate mental status, suicide ideation (especially at the beginning of therapy or when doses are increased or decreased); anxiety, social functioning, panic attacks; signs/symptoms of serotonin syndrome; blood glucose; weight and BMI (APA 2010; De Picker 2014; Perrin 2008; Pliszka 2007; Vetter 2008)

Pregnancy

Pregnancy Considerations

Congenital abnormalities have been reported in humans; however, a causal relationship has not been established. Tricyclic antidepressants may be associated with irritability, jitteriness, and convulsions (rare) in the neonate (Yonkers 2009). Due to pregnancy-induced physiologic changes, women who are pregnant may require dose adjustments late in pregnancy to achieve euthymia (Altshuler 1996).

The ACOG recommends that therapy for depression during pregnancy be individualized; treatment should incorporate the clinical expertise of the mental health clinician, obstetrician, primary health care provider, and pediatrician (ACOG 2008). According to the American Psychiatric Association (APA), the risks of medication treatment should be weighed against other treatment options and untreated depression. For women who discontinue antidepressant medications during pregnancy and who may be at high risk for postpartum depression, the medications can be restarted following delivery (APA 2010). Treatment algorithms have been developed by the ACOG and the APA for the management of depression in women prior to conception and during pregnancy (Yonkers 2009).

Pregnant women exposed to antidepressants during pregnancy are encouraged to enroll in the National Pregnancy Registry for Antidepressants (NPRAD). Women 18 to 45 years of age or their health care providers may contact the registry by calling 844-405-6185. Enrollment should be done as early in pregnancy as possible.

Patient Education

What is this drug used for?

• It is used to treat low mood (depression).
• It is used to help prevent bedwetting in children.
• It may be given to you for other reasons. Talk with the doctor.

Frequently reported side effects of this drug

• Dry mouth
• Lack of appetite
• Nausea
• Vomiting
• Diarrhea
• Taste changes
• Abdominal cramps
• Fatigue
• Weight loss
• Sweating a lot
• Flushing
• Fatigue

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

• Vision changes
• Eye pain
• Eye irritation
• Eyelid swelling
• Eye redness
• Depression like thoughts of suicide, anxiety, emotional instability, or confusion.
• High blood sugar like confusion, fatigue, increased thirst, increased hunger, passing a lot of urine, flushing, fast breathing, or breath that smells like fruit.
• Low blood sugar like dizziness, headache, fatigue, feeling weak, shaking, fast heartbeat, confusion, increased hunger, or sweating.
• Severe cerebrovascular disease like change in strength on one side is greater than the other, difficulty speaking or thinking, change in balance, or vision changes.
• Severe headache
• Severe dizziness
• Passing out
• Confusion
• Sensing things that seem real but are not
• Shortness of breath
• Excessive weight gain
• Swelling of arms or legs
• Unable to pass urine
• Severe loss of strength and energy
• Trouble sleeping
• Burning or numbness feeling
• Nightmares
• Severe constipation
• Sexual dysfunction
• Decreased sex drive
• Chills
• Sore throat
• Yellow skin
• Bruising
• Bleeding
• Chest pain
• Fast heartbeat
• Abnormal heartbeat
• Noise or ringing in the ears
• Abnormal movements
• Twitching
• Change in balance
• Trouble swallowing
• Trouble speaking
• Seizures
• Irritability
• Mood changes
• Panic attacks
• Severe abdominal pain
• Mouth irritation
• Mouth sores
• Enlarged breasts
• Nipple discharge
• Testicle swelling
• Hair loss
• Serotonin syndrome like dizziness, severe headache, agitation, sensing things that seem real but are not, fast heartbeat, abnormal heartbeat, flushing, tremors, sweating a lot, change in balance, severe nausea, or severe diarrhea.
• 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.