Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ANAFRANIL vs AMITRIL
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Clomipramine is a tricyclic antidepressant (TCA) that inhibits the reuptake of serotonin and norepinephrine, with a higher potency for serotonin reuptake inhibition. It also has anticholinergic, antihistaminergic, and alpha-adrenergic blocking properties.
Amitriptyline inhibits the reuptake of serotonin and norepinephrine, thereby increasing their synaptic concentrations. It also blocks histamine H1, alpha-1 adrenergic, and muscarinic receptors.
Obsessive-compulsive disorder (OCD),Off-label: depression, panic disorder, chronic pain, cataplexy associated with narcolepsy, premature ejaculation
Major depressive disorder,Neuropathic pain,Fibromyalgia,Migraine prophylaxis,Chronic tension-type headache,Insomnia (off-label),Irritable bowel syndrome (off-label)
Initial: 25 mg PO tid; increase gradually to 100-150 mg/day. Maximum: 250 mg/day. Maintenance: lowest effective dose.
Adults: Initial 25 mg PO once daily at bedtime, increase by 25 mg every 3-7 days as tolerated to typical maintenance 75-150 mg/day PO divided doses or single dose at bedtime. Maximum 300 mg/day.
Terminal elimination half-life of clomipramine is approximately 21-26 hours; its active metabolite, desmethylclomipramine, has a half-life of approximately 36-42 hours. Steady-state is achieved within 7-14 days.
Terminal elimination half-life: 15–25 hours (mean 20 h); may extend to >40 h in elderly or hepatic impairment.
Primarily hepatic via CYP1A2, CYP3A4, CYP2C19, and CYP2D6; active metabolite desmethylclomipramine formed via N-demethylation.
Hepatic, primarily via CYP2D6 and CYP3A4, with contributions from CYP1A2 and CYP2C19. Amitriptyline is metabolized to nortriptyline (active) and other metabolites.
Renal (primarily as conjugated metabolites, ~60-70% over 72 hours); fecal (biliary excretion of ~10-20%); <2% excreted unchanged in urine.
Renal: ~70% as metabolites, <5% unchanged; fecal: ~30% via bile.
97.6% bound primarily to alpha1-acid glycoprotein and albumin.
90–95% bound to albumin and alpha-1-acid glycoprotein.
Approximately 12-17 L/kg, indicating extensive tissue distribution.
Vd: 15–30 L/kg; extensive tissue distribution, including CNS.
Oral bioavailability is approximately 45-55% due to first-pass metabolism. IV administration yields 100%.
Oral: 30–60% due to first-pass metabolism.
No specific guidelines. Use with caution in severe renal impairment (Cr Cl <30 m L/min); consider dose reduction based on tolerability.
GFR 30-59 m L/min: Reduce dose by 50%. GFR 15-29 m L/min: Reduce dose by 75%. GFR <15 m L/min: Contraindicated. Hemodialysis: Not dialyzable; avoid use.
Child-Pugh A: no adjustment needed. Child-Pugh B: reduce dose by 50%. Child-Pugh C: contraindicated.
Child-Pugh A: No adjustment. Child-Pugh B: Reduce dose by 50%. Child-Pugh C: Use contraindicated or reduce dose by 75% with extreme caution.
Not recommended for children <10 years. For adolescents: initial 25 mg PO daily, increase slowly to 3 mg/kg/day or 100 mg/day maximum (whichever is lower).
Children ≥12 years: Initial 25-50 mg/day PO, increase gradually to 100 mg/day in divided doses. Children 6-11 years: 1-3 mg/kg/day PO in divided doses, not to exceed 100 mg/day. Not recommended under 6 years.
Initial: 10 mg PO daily; increase slowly to 30-50 mg/day. Monitor for orthostatic hypotension, sedation, and anticholinergic effects.
Initial 10-25 mg PO at bedtime, with gradual titration. Maintenance often 50-100 mg/day. Monitor for orthostatic hypotension, falls, and anticholinergic effects.
Suicidality and Antidepressant Drugs: Antidepressants increased the risk of suicidal thinking and behavior in children, adolescents, and young adults in short-term studies. Closely monitor for clinical worsening, suicidality, or unusual changes in behavior.
Amitriptyline is not approved for use in pediatric patients. Clinical worsening and suicide risk: Monitor for clinical worsening, suicidality, or unusual changes in behavior during initial therapy. Serotonin syndrome: Serotonin syndrome has been reported with SSRIs and SNRIs.
May increase risk of suicidal thoughts/behaviors; serotonin syndrome when used with other serotonergic drugs; lowering of seizure threshold; orthostatic hypotension; anticholinergic effects (e.g., urinary retention, blurred vision); cardiac conduction abnormalities; QT prolongation; neuroleptic malignant syndrome; angle-closure glaucoma; hyperpyrexia; withdrawal symptoms upon abrupt discontinuation; use with caution in patients with cardiovascular disease, hepatic impairment, renal impairment, history of seizures, and elderly patients.
Suicidality in children, adolescents, and young adults; serotonin syndrome; activation of mania/hypomania; seizures; angle-closure glaucoma; urinary retention; cardiovascular effects (QT prolongation, arrhythmias); impaired cognitive/motor performance.
Hypersensitivity to clomipramine or other tricyclics; concurrent use or within 14 days of MAO inhibitors; recent myocardial infarction; history of seizure disorder; narrow-angle glaucoma; urinary retention; concurrent use with linezolid or methylene blue.
Hypersensitivity to amitriptyline or any component; concomitant use with MAOIs or within 14 days of MAOI use; recent myocardial infarction; during acute recovery phase after MI; concomitant use with cisapride.
Avoid grapefruit and grapefruit juice as they may increase clomipramine levels. Take with food to reduce gastric upset. Avoid excessive caffeine; it may increase side effects like anxiety or tremors. Limit alcohol due to additive CNS depression.
Avoid grapefruit and grapefruit juice as they may increase serum levels of amitriptyline. Limit tyramine-rich foods (aged cheeses, cured meats, fermented products) if taking MAOIs concurrently (contraindicated). Alcohol consumption may enhance sedative effects and is not recommended. High-fat meals may delay absorption but do not significantly alter overall exposure.
First trimester: Limited data; possible increased risk of congenital heart defects (RR ~1.3). Second/third trimester: Risk of neonatal withdrawal syndrome (jitteriness, feeding difficulties, respiratory distress) and persistent pulmonary hypertension of the newborn (PPHN) with late exposure.
First trimester: Possible increased risk of cardiovascular malformations (OR ~1.2-1.5). Second/third trimester: Risk of neonatal withdrawal syndrome (irritability, feeding difficulties) and direct toxic effects (tachycardia, urinary retention). Late third trimester: Possible persistent pulmonary hypertension of the newborn (PPHN) with SSRI-like effects, though data limited for tricyclics.
Anafranil (clomipramine) is excreted into breast milk. M/P ratio approximately 0.5-1.0. Relative infant dose estimated 1-2% of maternal weight-adjusted dose. Monitor infant for drowsiness, feeding difficulties, and weight loss. Generally compatible with caution.
M/P ratio approximately 1.0-1.5. Excreted in breast milk in low amounts. Infant serum levels are usually subtherapeutic but cases of drowsiness, irritability reported. Use with caution; monitor infant for sedation and feeding difficulties. American Academy of Pediatrics considers compatible with breastfeeding if infant is healthy and full-term.
Due to increased plasma volume and enhanced hepatic metabolism in pregnancy, serum levels may decrease by up to 50%. Consider dose adjustment based on clinical response and trough levels; typical increase by 25-50% may be needed in later pregnancy. Postpartum, reduce dose to prepregnancy levels over 1-2 weeks.
Due to increased plasma volume and hepatic metabolism in pregnancy, lower serum concentrations may occur. Monitor clinical response; dose adjustments may be needed but no standard guidelines. Use lowest effective dose. Taper if discontinuing to avoid withdrawal.
Anafranil (clomipramine) is a tricyclic antidepressant (TCA) primarily used for obsessive-compulsive disorder (OCD). Monitor for QT prolongation, especially in patients with cardiac risk factors or on other QT-prolonging drugs. Due to anticholinergic effects, use cautiously in elderly, those with BPH, or narrow-angle glaucoma. Start low and titrate slowly to minimize side effects. Therapeutic response may take 2-4 weeks. Do not discontinue abruptly due to withdrawal symptoms.
For neuropathic pain, start at 10-25 mg at bedtime; titrate slowly to reduce sedative effects. Monitor QTc interval at baseline and with dose increases, especially in patients with cardiac risk factors. Anticholinergic effects (dry mouth, constipation) are common; consider prophylactic stool softeners. Avoid abrupt discontinuation; taper over 2-4 weeks to prevent withdrawal symptoms.
Take exactly as prescribed; do not adjust dose without consulting your doctor.,It may take several weeks to feel the full benefit; do not stop suddenly.,Avoid alcohol and other CNS depressants.,Report any suicidal thoughts, worsening depression, or mood changes immediately.,May cause drowsiness, dizziness, or blurred vision; avoid driving until you know how it affects you.,Dry mouth, constipation, and urinary retention are common; increase fluid intake and dietary fiber.,Use sun protection; this medication can increase sensitivity to sunlight.,Do not take with MAO inhibitors (e.g., linezolid, methylene blue) or within 14 days of stopping them.
Take exactly as prescribed, usually once daily at bedtime due to drowsiness.,Do not stop suddenly; taper under doctor's guidance to avoid nausea, headache, or insomnia.,Avoid alcohol and other CNS depressants (e.g., sedatives, opioids) as they increase sedation risk.,Report any signs of serotonin syndrome (e.g., agitation, hallucinations, rapid heart rate) or cardiac symptoms (e.g., palpitations, fainting).,May cause dry mouth, constipation, blurred vision; use sugar-free gum, hydrate, and consider fiber supplements.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about ANAFRANIL vs AMITRIL, answered by our medical review team.
ANAFRANIL is a Tricyclic Antidepressant that works by Clomipramine is a tricyclic antidepressant (TCA) that inhibits the reuptake of serotonin and norepinephrine, with a higher potency for serotonin reuptake inhibition. It also has anticholinergic, antihistaminergic, and alpha-adrenergic blocking properties.. AMITRIL is a Tricyclic Antidepressant that works by Amitriptyline inhibits the reuptake of serotonin and norepinephrine, thereby increasing their synaptic concentrations. It also blocks histamine H1, alpha-1 adrenergic, and muscarinic receptors.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ANAFRANIL and AMITRIL depend on the specific clinical indication. These are both Tricyclic Antidepressant agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of ANAFRANIL is: Initial: 25 mg PO tid; increase gradually to 100-150 mg/day. Maximum: 250 mg/day. Maintenance: lowest effective dose.. The standard adult dose of AMITRIL is: Adults: Initial 25 mg PO once daily at bedtime, increase by 25 mg every 3-7 days as tolerated to typical maintenance 75-150 mg/day PO divided doses or single dose at bedtime. Maximum 300 mg/day.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between ANAFRANIL and AMITRIL in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. ANAFRANIL is classified as Category C. First trimester: Limited data; possible increased risk of congenital heart defects (RR ~1.3). Second/third trimester: Risk of neonatal withdrawal syndrome (jitteriness, feeding dif. AMITRIL is classified as Category C. First trimester: Possible increased risk of cardiovascular malformations (OR ~1.2-1.5). Second/third trimester: Risk of neonatal withdrawal syndrome (irritability, feeding difficul. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.