Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ASENDIN vs AMOXAPINE
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Amoxapine, a dibenzoxazepine tricyclic antidepressant, primarily inhibits the reuptake of norepinephrine and serotonin. Its metabolite, 7-hydroxyamoxapine, exhibits dopamine D2 receptor antagonism, contributing to its antipsychotic effects.
Selective inhibitor of serotonin reuptake and, to a lesser extent, norepinephrine reuptake. Also exhibits weak dopamine D2 receptor antagonism and alpha1-adrenergic blockade.
Treatment of depression (neurotic and psychotic depression),Off-label: anxiety disorders, agitation in schizophrenia
Major depressive disorder,Anxiety,Panic disorder,Off-label: neuropathic pain, insomnia
50 mg orally three times daily, increased gradually to 100-200 mg/day in divided doses. Max 300 mg/day.
200-300 mg/day orally in divided doses, initially 50 mg three times daily; maximum 400 mg/day
Terminal elimination half-life is approximately 24-30 hours. Clinical context: Steady-state is reached within 5-7 days; the half-life supports once-daily dosing in most patients.
Parent drug: 8-12 hours; active metabolite (8-hydroxyamoxapine): approximately 30 hours; steady-state achieved in 3-5 days
Primarily hepatic via CYP450 enzymes, notably CYP2D6 and CYP3A4. Major metabolites: 7-hydroxyamoxapine (active) and 8-hydroxyamoxapine.
Primarily hepatic via CYP2D6 and CYP3A4; major metabolite is 8-hydroxyamoxapine, which is pharmacologically active.
Renal (approximately 50% as unchanged drug and metabolites), biliary/fecal (30-40%), with the remainder as other metabolites; <10% excreted unchanged in urine.
Primarily renal (approximately 60-70% as metabolites, <5% unchanged); minimal fecal elimination (<10%)
90-95% bound to plasma proteins, primarily albumin and alpha-1-acid glycoprotein.
Approximately 80-90%, primarily to albumin and alpha-1-acid glycoprotein
Apparent volume of distribution is 8-10 L/kg, indicating extensive tissue distribution and accumulation in peripheral compartments.
0.8-1.2 L/kg, indicating extensive tissue distribution
Oral bioavailability is approximately 70-80% due to first-pass metabolism. No parenteral formulation is available; only oral route.
Oral: approximately 60-70% due to first-pass metabolism
Cr Cl 30-60 m L/min: reduce dose by 25-50%. Cr Cl <30 m L/min: contraindicated.
GFR 10-50 m L/min: reduce dose by 50%; GFR <10 m L/min: avoid use or reduce dose by 75%
Child-Pugh class C: contraindicated. Child-Pugh class B: reduce dose by 50%.
Child-Pugh Class A: start at 25 mg twice daily; Class B: 25 mg once daily; Class C: avoid use
Not recommended for use in children due to lack of safety data.
Not recommended for use in children under 16 years
Initial dose 25 mg twice daily, increase slowly with close monitoring due to increased sensitivity and anticholinergic effects.
Initial dose 25 mg twice daily, increase slowly; maximum 300 mg/day
Increased risk of suicidal thinking and behavior in children, adolescents, and young adults with major depressive disorder and other psychiatric disorders.
Increased risk of suicidal thinking and behavior in children, adolescents, and young adults with major depressive disorder and other psychiatric disorders.
Suicidality risk,Neuroleptic malignant syndrome,Tardive dyskinesia,Seizure threshold lowering,Cardiotoxicity (QT prolongation, arrhythmias),Anticholinergic effects,Hypotension,Hepatic impairment
Suicidality risk in young adults,Serotonin syndrome when combined with other serotonergic drugs,Extrapyramidal symptoms due to weak D2 blockade,Seizure risk,Cardiotoxicity (prolonged QT interval) at high doses,Agranulocytosis (rare)
Hypersensitivity to amoxapine or any component,Concomitant use with MAOIs or within 14 days of MAOI discontinuation,Acute recovery phase after myocardial infarction,Known alcohol or barbiturate intoxication
Hypersensitivity to amoxapine or any dibenzoxazepine,Concomitant use with MAOIs (including linezolid and methylene blue),Recent myocardial infarction,Uncontrolled narrow-angle glaucoma,Urinary retention,QT prolongation or concurrent use of drugs that prolong QT
Avoid ethanol; may cause additive CNS depression. No specific food interactions; however, taking with food may reduce GI upset.
Avoid alcohol and beverages with high tyramine content (e.g., aged cheese, cured meats, fermented foods) only if patient is also on MAOIs; not a specific requirement for amoxapine alone. Grapefruit juice may inhibit metabolism; advise caution or avoid large amounts. For patients with hypertension or seizure disorders, avoid excessive caffeine.
ASENDIN (amoxapine) is classified as FDA Pregnancy Category C. First trimester: Limited human data; animal studies show fetal toxicity at high doses. Risk of congenital malformations cannot be excluded. Second and third trimesters: Neonates may exhibit transient withdrawal symptoms (jitteriness, respiratory depression) or serotonin syndrome if used near term. Avoid use unless benefit outweighs risk.
First trimester: Limited data; risk of neural tube defects? Second trimester: No specific associations. Third trimester: Risk of neonatal withdrawal (irritability, feeding difficulties). Overall: FDA Category C; avoid in first trimester if possible.
Amoxapine is excreted in human breast milk. M/P ratio is unknown. Due to limited safety data, breastfeeding is not recommended during therapy. If essential, monitor infant for sedation, poor feeding, and weight loss.
Excreted in breast milk; M/P ratio not established. Use caution due to potential for infant sedation and anticholinergic effects; monitor for drowsiness and poor feeding.
No specific dose adjustments are established. Due to increased plasma volume and hepatic metabolism in pregnancy, therapeutic drug monitoring is recommended to ensure efficacy and avoid toxicity. Initiate at low doses and titrate based on clinical response and serum concentrations if available.
No established dose adjustments; increased clearance in pregnancy may require dose increase to maintain efficacy; monitor therapeutic response and serum levels if available.
Asendin (amoxapine) is a dibenzoxazepine antidepressant with a 7-hydroxy metabolite that confers dopamine blockade, giving it a unique antipsychotic profile. Monitor for extrapyramidal symptoms and tardive dyskinesia, especially in elderly patients. Due to significant anticholinergic effects, use cautiously in patients with benign prostatic hyperplasia, narrow-angle glaucoma, or cognitive impairment. Avoid coadministration with MAOIs; allow at least 14 days between therapies. May cause a false-positive urine amphetamine screen due to structural similarity.
Amoxapine is a dibenzoxazepine antidepressant with both tricyclic-like reuptake inhibition and dopamine receptor blocking properties. Monitor for extrapyramidal symptoms (EPS) and tardive dyskinesia, especially in elderly. Due to dopamine blockade, it may cause hyperprolactinemia. For patients with seizures, use cautiously; dose-dependent seizure risk is higher than with other TCAs. Onset of antidepressant effect may be 2-4 weeks. Use lower initial doses in elderly and hepatic impairment. Avoid in recent myocardial infarction.
Take exactly as prescribed; do not stop abruptly or adjust dose without consulting your doctor.,Avoid alcohol and other CNS depressants as they can increase drowsiness and dizziness.,May cause dry mouth; use sugar-free gum or candy to alleviate.,Report any unusual movements, especially of the face or tongue, or severe muscle stiffness.,May increase sensitivity to sunlight; use sunscreen and protective clothing.,Inform all healthcare providers you are taking this medication.
Take exactly as prescribed; do not increase or stop abruptly without consulting your doctor.,May cause drowsiness or dizziness; avoid driving or operating heavy machinery until you know how the medication affects you.,Avoid alcohol and other CNS depressants.,Report any muscle stiffness, tremor, restlessness, or unusual movements of the face or tongue.,Notify your doctor if you experience rapid or irregular heartbeat, difficulty urinating, or blurred vision.,May cause dry mouth; use sugarless candy or gum and maintain good oral hygiene.,Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.,Do not take any other medications, including over-the-counter products, without approval from your healthcare provider.
No interactions on record
"Combined use of Oxprenolol, a non-selective beta-blocker with intrinsic sympathomimetic activity, and Amoxapine, a tricyclic antidepressant, may lead to additive cardiovascular adverse effects. Amoxapine can inhibit the metabolism of beta-blockers via competition for CYP450 enzymes, increasing oxprenolol plasma concentrations. This interaction heightens the risk of bradycardia, hypotension, and may precipitate heart block or arrhythmias, particularly in patients with pre-existing cardiac disease."
"The combination of amoxapine, a tricyclic antidepressant with strong anticholinergic properties, and clidinium, a quaternary ammonium anticholinergic used for gastrointestinal spasms, results in additive anticholinergic effects. This can lead to excessive peripheral and central anticholinergic adverse effects such as dry mouth, blurred vision, constipation, urinary retention, tachycardia, cognitive impairment, and exacerbation of glaucoma or paralytic ileus. In severe cases, anticholinergic toxicity may manifest as hyperthermia, delirium, or seizures, particularly in elderly patients or those with pre-existing conditions."
"Telavancin, a lipoglycopeptide antibiotic, prolongs the QT interval by inhibiting the delayed rectifier potassium current (IKr) in cardiac myocytes. Amoxapine, a tricyclic antidepressant, also blocks cardiac sodium and potassium channels, leading to dose-dependent QTc prolongation. Concomitant use increases the risk of torsade de pointes, ventricular arrhythmias, and sudden cardiac death, particularly in patients with electrolyte imbalances, bradycardia, or preexisting QT prolongation."
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about ASENDIN vs AMOXAPINE, answered by our medical review team.
ASENDIN is a Tricyclic Antidepressant that works by Amoxapine, a dibenzoxazepine tricyclic antidepressant, primarily inhibits the reuptake of norepinephrine and serotonin. Its metabolite, 7-hydroxyamoxapine, exhibits dopamine D2 receptor antagonism, contributing to its antipsychotic effects.. AMOXAPINE is a Tricyclic Antidepressant that works by Selective inhibitor of serotonin reuptake and, to a lesser extent, norepinephrine reuptake. Also exhibits weak dopamine D2 receptor antagonism and alpha1-adrenergic blockade.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ASENDIN and AMOXAPINE 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 ASENDIN is: 50 mg orally three times daily, increased gradually to 100-200 mg/day in divided doses. Max 300 mg/day.. The standard adult dose of AMOXAPINE is: 200-300 mg/day orally in divided doses, initially 50 mg three times daily; maximum 400 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 ASENDIN and AMOXAPINE 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. ASENDIN is classified as Category C. ASENDIN (amoxapine) is classified as FDA Pregnancy Category C. First trimester: Limited human data; animal studies show fetal toxicity at high doses. Risk of congenital malformatio. AMOXAPINE is classified as Category C. First trimester: Limited data; risk of neural tube defects? Second trimester: No specific associations. Third trimester: Risk of neonatal withdrawal (irritability, feeding difficul. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.