Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
AMITID vs ANAFRANIL
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Amitriptyline inhibits the reuptake of serotonin and norepinephrine, increasing their levels in the synaptic cleft. It also blocks histamine H1, alpha-adrenergic, and muscarinic receptors.
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.
Major depressive disorder,Neuropathic pain,Fibromyalgia,Migraine prophylaxis,Chronic tension-type headache,Irritable bowel syndrome,Enuresis
Obsessive-compulsive disorder (OCD),Off-label: depression, panic disorder, chronic pain, cataplexy associated with narcolepsy, premature ejaculation
75–150 mg orally once daily at bedtime; maximum 200 mg daily. For depression, initial dose 25–75 mg/day, titrate up to 150 mg/day. For neuropathic pain, start 10–25 mg at bedtime, increase to 25–100 mg/day.
Initial: 25 mg PO tid; increase gradually to 100-150 mg/day. Maximum: 250 mg/day. Maintenance: lowest effective dose.
Terminal elimination half-life is 7-10 hours; clinically, steady-state is reached within 2-3 days.
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.
Hepatic via CYP2D6, CYP2C19, CYP3A4; active metabolite nortriptyline.
Primarily hepatic via CYP1A2, CYP3A4, CYP2C19, and CYP2D6; active metabolite desmethylclomipramine formed via N-demethylation.
Renal: 60-80% as metabolites, <5% unchanged; Biliary/Fecal: 20-30% as metabolites.
Renal (primarily as conjugated metabolites, ~60-70% over 72 hours); fecal (biliary excretion of ~10-20%); <2% excreted unchanged in urine.
90-95% bound primarily to albumin and α1-acid glycoprotein.
97.6% bound primarily to alpha1-acid glycoprotein and albumin.
3-5 L/kg; indicates extensive tissue distribution.
Approximately 12-17 L/kg, indicating extensive tissue distribution.
Oral: 60-70%; Intravenous: 100%.
Oral bioavailability is approximately 45-55% due to first-pass metabolism. IV administration yields 100%.
GFR ≥30 m L/min: no adjustment. GFR 15–29 m L/min: reduce dose by 50%. GFR <15 m L/min: contraindicated or use with extreme caution, maximum 25 mg/day.
No specific guidelines. Use with caution in severe renal impairment (Cr Cl <30 m L/min); consider dose reduction based on tolerability.
Child-Pugh A: no adjustment. Child-Pugh B: reduce dose by 50%. Child-Pugh C: avoid use.
Child-Pugh A: no adjustment needed. Child-Pugh B: reduce dose by 50%. Child-Pugh C: contraindicated.
Not FDA-approved for use in children <12 years. For adolescent depression (off-label): start 25 mg/day, titrate up to 50–100 mg/day. Weight-based: 1–3 mg/kg/day, not to exceed 150 mg/day.
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).
Start at 10–25 mg orally at bedtime; increase by 10–25 mg every 3–7 days to effective dose, typically 50–75 mg/day. Maximum 100 mg/day due to increased risk of anticholinergic effects, sedation, and orthostatic hypotension.
Initial: 10 mg PO daily; increase slowly to 30-50 mg/day. Monitor for orthostatic hypotension, sedation, and anticholinergic effects.
Antidepressants increase the risk of suicidal thinking and behavior in children, adolescents, and young adults with major depressive disorder and other psychiatric disorders.
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.
Clinical worsening and suicide risk,Serotonin syndrome,Cardiovascular effects (QT prolongation, arrhythmia),Anticholinergic effects,Seizures,Angle-closure glaucoma,Urinary retention,Hepatic impairment,Hyponatremia
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.
Hypersensitivity to amitriptyline,Concomitant use with MAOIs (within 14 days),Acute recovery phase after myocardial infarction,Concurrent use of cisapride or other QT-prolonging drugs
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.
Avoid grapefruit and grapefruit juice as they may increase drug levels. Tyramine-rich foods (aged cheese, cured meats, fermented products) should be limited due to risk of hypertensive crisis. Maintain adequate fluid intake to prevent constipation.
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.
First trimester: Amitriptyline (likely the active ingredient in AMITID) is associated with a small increased risk of congenital malformations, particularly cardiovascular defects, based on observational studies. Absolute risk is low. Second and third trimesters: Chronic use may lead to neonatal adaptation syndrome (irritability, respiratory distress) and anticholinergic effects (e.g., constipation, urinary retention). Late third trimester exposure may increase risk of persistent pulmonary hypertension of the newborn (PPHN).
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.
Amitriptyline and its active metabolite nortriptyline are excreted into breast milk with a milk-to-plasma (M/P) ratio of approximately 0.5–1.5. Relative infant dose is low (estimated <2% of weight-adjusted maternal dose). No adverse effects reported in infants followed prospectively. The American Academy of Pediatrics considers amitriptyline compatible with breastfeeding. However, monitor infant for sedation, poor feeding, and growth.
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.
Pharmacokinetic changes in pregnancy (increased volume of distribution, hepatic metabolism, renal clearance) may reduce serum drug concentrations. Therapeutic drug monitoring (if available) can guide dose adjustments; clinical response may require dose increases by 30–50% in the second and third trimesters. Avoid abrupt withdrawal; taper if discontinuing.
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.
Amitriptyline is a tricyclic antidepressant with strong anticholinergic effects; monitor for QT prolongation, especially in elderly or those with cardiac disease. Start low (10-25 mg at bedtime) and titrate slowly. Avoid in recent MI, narrow-angle glaucoma, and urinary retention. Use with caution in seizure disorders.
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.
Take this medication at bedtime as it may cause drowsiness.,Avoid alcohol and other CNS depressants.,Do not stop abruptly; taper under medical supervision to avoid withdrawal symptoms.,May cause dry mouth, constipation, blurred vision; report severe side effects like fainting or irregular heartbeat.,Full therapeutic effect may take 2-4 weeks.
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.
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 AMITID vs ANAFRANIL, answered by our medical review team.
AMITID is a Tricyclic Antidepressant that works by Amitriptyline inhibits the reuptake of serotonin and norepinephrine, increasing their levels in the synaptic cleft. It also blocks histamine H1, alpha-adrenergic, and muscarinic receptors.. 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.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between AMITID and ANAFRANIL 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 AMITID is: 75–150 mg orally once daily at bedtime; maximum 200 mg daily. For depression, initial dose 25–75 mg/day, titrate up to 150 mg/day. For neuropathic pain, start 10–25 mg at bedtime, increase to 25–100 mg/day.. 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.. 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 AMITID and ANAFRANIL 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. AMITID is classified as Category C. First trimester: Amitriptyline (likely the active ingredient in AMITID) is associated with a small increased risk of congenital malformations, particularly cardiovascular defects, . 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. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.