amoxapine

Adjunctive therapy

Brands: Asendin

Last reviewed 2025-12-30

Reviewed by PsychMed Editorial Team.

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Quick answers

What is amoxapine?
Amoxapine (brand Asendin; generics) is an older antidepressant indicated for depression, including depression accompanied by anxiety or agitation (label). It is structurally distinct from TCAs but shares many TCA-like safety considerations.
What is Asendin?
Asendin is a brand name for amoxapine.
What is Asendin (amoxapine) used for?
Label indications include: Depression, including depression with anxiety or agitation (label).
What drug class is Asendin (amoxapine)?
Dibenzoxazepine antidepressant with norepinephrine/serotonin reuptake inhibition and clinically meaningful dopamine receptor blockade (EPS/TD risk).
What strengths does Asendin (amoxapine) come in?
Oral tablets (label): 25 mg, 50 mg, 100 mg, 150 mg.

Snapshot

Class: Adjunctive therapy
Common US brands: Asendin
Therapeutic drug monitoring not routinely recommended.
Last reviewed: 2025-12-30

Label indications

Depression, including depression with anxiety or agitation (label).

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Clinical Highlights

Amoxapine (brand Asendin; generics) is an older antidepressant indicated for depression, including depression accompanied by anxiety or agitation (label). It is structurally distinct from TCAs but shares many TCA-like safety considerations. A key differentiator is clinically meaningful dopamine receptor blocking activity. This can produce EPS and is associated with a warning about Tardive dyskinesia—a side-effect profile that is unusual for antidepressants and overlaps with antipsychotic monitoring concerns (label).

Because of anticholinergic effects, orthostasis, seizure risk at higher doses, and the potential for movement disorders, amoxapine is generally used selectively rather than as a first-line depression option (clinical).
The label reports a parent half-life of ~8 hours, with a major active metabolite (8-hydroxy-amoxapine) having a longer half-life of ~30 hours, which can extend both benefits and adverse effects (label).
The compare view, amoxapine evidence feed, and amoxapine print page help weigh anticholinergic burden and movement-disorder risk when an antidepressant choice intersects with psychosis or prior antipsychotic exposure.

Dosing & Formulations

Oral tablets (label): 25 mg, 50 mg, 100 mg, 150 mg. Label dosing is individualized. Common initiation is 50 mg two or three times daily, with gradual increases based on response and tolerability (label).

Label allows single-bedtime dosing when the total daily dose does not exceed 300 mg; higher total daily doses are divided (label).
Because of seizure and movement-disorder risk, clinicians often avoid rapid escalation and reassess benefit before pushing into higher-dose ranges (clinical).

Monitoring & Risks

Boxed warning: antidepressants increase risk of suicidal thoughts and behaviors in children, adolescents, and young adults; close monitoring early in treatment is typical (label). Movement disorders: dopamine-blocking activity can produce EPS and is associated with a warning about Tardive dyskinesia; monitoring resembles antipsychotic movement screening in higher-risk patients (label/clinical).

Anticholinergic and sedating effects (constipation, urinary retention, grogginess) can be clinically significant, especially in older adults and with polypharmacy (label/clinical).
Seizure threshold reduction can occur, especially at higher doses or with other pro-convulsant medications (label/class).
Cardiac conduction effects and arrhythmias are class risks for tricyclic-like agents; ECG planning is often used when baseline risk is elevated (clinical).

Drug Interactions

MAOIs are contraindicated; washout periods are used to reduce risk of serotonin syndrome and severe reactions (label). Additive CNS depression can occur with alcohol, benzodiazepines, opioids, and other sedatives; functional safety is a common review topic (label/clinical).

CYP2D6 inhibition (e.g., fluoxetine, paroxetine, quinidine) can raise exposure of tricyclic-like agents; medication reconciliation is commonly used to anticipate toxicity risk (clinical).
Other anticholinergic medications can compound constipation, urinary retention, and delirium risk (clinical).

Practice Notes

Amoxapine is generally positioned after SSRIs/SNRIs in depression guidelines because safer alternatives exist for most patients (APA/CANMAT/clinical). If abnormal movements, rigidity, restlessness, or akathisia emerge, clinicians commonly reassess the medication choice and consider switching to a non–dopamine-blocking antidepressant (label/clinical).

When depressive symptoms occur in bipolar disorder, antidepressants are commonly paired with a mood stabilizer and monitored for Mania/Hypomania; see the bipolar disorder hub for longitudinal care pathways.
When discontinuing after longer courses, gradual tapering is commonly used to reduce withdrawal symptoms and to distinguish withdrawal from relapse (clinical).

References

Amoxapine tablets prescribing information — DailyMed (2024)
APA Clinical Practice Guideline for the Treatment of Depression — American Psychiatric Association (2023)Guidelinedepressionclinical
CANMAT 2024 Clinical Guidelines for Major Depressive Disorder — Canadian Journal of Psychiatry (2024)
Consensus Guidelines for Therapeutic Drug Monitoring in Neuropsychopharmacology: Update 2017 — Pharmacopsychiatry (2018)