💊 PHARM STUDY GUIDE: AMITRIPTYLINE (Elavil) Class: Tricyclic Antidepressant (TCA)

🧠 MOA (80/20): Blocks neuronal reuptake of serotonin & norepinephrine; also anticholinergic, antihistamine, and sodium-channel effects → efficacy + side-effect burden. NCBI

📋 Indications (what you’ll actually see):

• Major depressive disorder
• Off-label, low dose: neuropathic pain, migraine prevention, insomnia (sedating).

⚠️ Red-Flag Side Effects (Prioritize 🚨):

1. Cardiac toxicity – QT prolongation, conduction block, ventricular arrhythmias; overdose can be fatal. Monitor ECG/electrolytes in risk pts.
2. Serotonin syndrome (with MAOIs/serotonergics): fever, agitation, hyperreflexia, diarrhea, tremor, clonus. Stop drug; supportive care; consider cyproheptadine.
3. Anticholinergic crisis – delirium, urinary retention, ileus, hyperthermia (elderly esp.).
4. Orthostatic hypotension & falls (α1-blockade).
5. Suicidality boxed warning in children, adolescents, young adults—highest risk at start & dose changes.

🩺 Nursing Interventions & Monitoring:

• Baseline & periodic BP/HR, ECG if cardiac risk, electrolyte check (K/Mg) if QT risk.
• Screen for suicidal ideation early and with any dose change.
• Watch for anticholinergic effects (bowel regimen, fluids), falls, urinary retention.
• Assess for drug interactions (see below) and serotonin syndrome.

🚫 Contraindications & Dangerous Combos:

• MAOIs: contraindicated; 14-day washout (risk of hyperpyrexia/convulsions/SS).
• Strong CYP2D6 inhibitors (e.g., fluoxetine, paroxetine) ↑ TCA levels → toxicity; avoid or adjust/monitor closely.
• Additive QT-prolonging meds (amiodarone, macrolides, antipsychotics) → arrhythmia risk.
• Potentiation with other anticholinergics/CNS depressants (falls, delirium).

🎯 Top 5 High-Yield Takeaways:

1. Powerful but not first-line due to side effects/toxicity—reserve for refractory depression or low-dose pain/migraine.
2. Cardiac safety first: screen QT risks, consider baseline ECG.
3. Night dosing, slow titration, and taper to discontinue.
4. Avoid MAOIs; beware CYP2D6 inhibitors (e.g., fluoxetine).
5. Monitor suicidality, anticholinergic burden, falls, and serotonin syndrome.

🧩 80/20 Summary: Think TCA = reuptake block + anticholinergic + cardiac risk. Safe use = low & slow, night dose, ECG when needed, interaction check, taper, monitor mood & SS.