Tricyclic Antidepressants (TCAs)

Psychiatric

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Examples

amitriptylinenortriptylineimipramineclomipramine

Prefix / Suffix: -triptyline, -ipramine

Physiology

Older antidepressants that affect multiple neurotransmitter systems and receptors, leading to broader side effects.

Mechanism of Action

Block reuptake of serotonin and norepinephrine; also block muscarinic, histamine, and alpha-adrenergic receptors.

Indications

Major depression (when SSRIs/SNRIs ineffective)
Neuropathic pain
Migraine prophylaxis
OCD (clomipramine)

Side Effects / Adverse Effects

Anticholinergic effects (dry mouth, constipation, urinary retention, blurred vision)
Orthostatic hypotension
Sedation
Cardiotoxicity — QT prolongation, arrhythmias (lethal in overdose)
Weight gain

Contraindications

Recent MI
Cardiac arrhythmias
Concurrent MAOI use
Narrow-angle glaucoma

Nursing Considerations

Highly lethal in overdose — limit prescription quantities
Monitor ECG, especially in elderly and cardiac patients
Rise slowly — orthostatic hypotension common
Manage anticholinergic effects (sugar-free gum, fluids, fiber)
Give at bedtime (sedation)
Takes 2–4 weeks for full effect

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Disclaimer: PharmPal Nurse is for education only and is not medical advice. Do not use it to diagnose, treat, prescribe, or make patient-care decisions; always verify with current drug references, your instructor, facility policy, and a licensed provider. In emergencies, call local emergency services.