trimipramine

Adjunctive therapy

Brands: Surmontil

Last reviewed 2025-12-30

Reviewed by PsychMed Editorial Team.

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Quick answers

What is trimipramine?
Trimipramine (brand Surmontil; generics) is a tricyclic antidepressant (TCA) indicated for the relief of symptoms of depression. It is often characterized by a sedating, anxiety-reducing profile compared with more “activating” TCAs (label/clinical).
What is Surmontil?
Surmontil is a brand name for trimipramine.
What is Surmontil (trimipramine) used for?
Label indications include: Depression.
What drug class is Surmontil (trimipramine)?
Tertiary-amine tricyclic antidepressant (TCA) with a sedating/anxiolytic clinical profile; mixed monoamine effects plus strong H1/α1/muscarinic antagonism.
What strengths does Surmontil (trimipramine) come in?
Oral capsules (label): 25 mg, 50 mg, 100 mg.

Snapshot

Class: Adjunctive therapy
Common US brands: Surmontil
Therapeutic drug monitoring recommended; reference range 150–300 ng/mL.
Last reviewed: 2025-12-30

Label indications

Depression.

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Clinical Highlights

Trimipramine (brand Surmontil; generics) is a tricyclic antidepressant (TCA) indicated for the relief of symptoms of depression. It is often characterized by a sedating, anxiety-reducing profile compared with more “activating” TCAs (label/clinical). Like other TCAs, trimipramine has a narrow therapeutic index and is dangerous in overdose. Care plans often include safe-storage counseling and attention to the amount dispensed (clinical).

Because sedation and Orthostatic hypotension are common and can be amplified by polypharmacy, trimipramine is typically used selectively and titrated cautiously in older adults or those with falls risk (label/clinical).
Therapeutic drug monitoring (TDM) is used for TCAs to support adequate exposure while avoiding toxicity. The AGNP guideline therapeutic reference range for trimipramine is 150–300 ng/mL (Hiemke 2018).
The compare view, trimipramine evidence feed, and trimipramine print page support shared decision-making when balancing sedation goals against anticholinergic and cardiac risk.

Dosing & Formulations

Oral capsules (label): 25 mg, 50 mg, 100 mg. Label dosing is individualized. Outpatient titration often starts at lower total daily doses (commonly 75 mg/day) and increases toward 150 mg/day as tolerated; higher-dose regimens are more often reserved for closely monitored settings (label).

Older adults and medically frail patients typically start lower (e.g., 50 mg/day or less) with slower titration due to orthostasis and confusion risk (label/clinical).
For TCAs, clinicians often obtain an ECG in higher-risk patients and consider TDM after steady state or after major interaction changes (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). Sedation, daytime grogginess, and impaired balance are common limiting effects; falls risk is higher in older adults and with other sedatives (label/clinical).

Anticholinergic side effects (constipation, urinary retention, blurry vision, cognitive slowing) can be prominent and often drive discontinuation in older adults (label/clinical).
Cardiac conduction effects (QRS/QT changes) and arrhythmias are key safety issues for the TCA class; ECG monitoring is often used when risk is elevated (clinical).
Mood switching can occur in bipolar-spectrum illness; monitoring for Mania/Hypomania is commonly coordinated when treating depressive episodes (clinical).

Drug Interactions

MAOIs are contraindicated; washout periods are used to reduce risk of Serotonin syndrome and hypertensive reactions (label). Strong CYP2D6 inhibitors (fluoxetine, paroxetine, bupropion, quinidine) can raise TCA exposure; dose adjustments and/or TDM are common strategies (clinical).

Additive sedation and respiratory risk can occur with alcohol, benzodiazepines, opioids, and sedating antipsychotics (clinical).
Other anticholinergic drugs (some antipsychotics, antihistamines) can compound constipation, urinary retention, and delirium risk (clinical).

Practice Notes

Trimipramine is generally positioned after SSRI/SNRI trials in major depressive disorder guidelines because TCAs have higher overdose risk and require more safety monitoring (APA/CANMAT/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.

If sedation is the desired effect (e.g., insomnia comorbidity), clinicians often compare alternatives with clearer evidence and lower anticholinergic burden before escalating TCA doses (clinical).
When discontinuing after longer courses, gradual tapering is commonly used to reduce cholinergic rebound and to distinguish withdrawal from relapse (clinical).

References

Trimipramine maleate capsules prescribing information — DailyMed (2025)
Consensus Guidelines for Therapeutic Drug Monitoring in Neuropsychopharmacology: Update 2017 — Pharmacopsychiatry (2018)
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)