Trade Names: Elavil and others
Drug Class: Tricyclic antidepressant
Preparations: 10-, 25-, 50-, 75-, 100-, 150-mg tablets
Dose: Initially, for fibromyalgia 10 mg is taken 2 hours before bedtime. The dose can be increased, if tolerated. The usual maintenance dose for fibromyalgia is 10–75 mg taken 2 hours before bedtime. The maximum daily dose for depression is 300 mg/day.
Indications: Depression, fibromyalgia, insomnia, an adjunct for pain control (chronic or neuropathic), prophylaxis for migraines
Mechanism of Action: Inhibits uptake of norepinephrine and serotonin in adrenergic and serotonergic neurons
Contraindications: Hypersensitivity. Avoid in recovery period of myocardial infarction or if arrhythmias exist. Avoid for at least 14 days after patient has received a MAOI. Avoid in patients with narrow-angle glaucoma.
Precautions: Antidepressants may increase suicidality, particularly in children and adolescents. Escalate dose slowly; it may cause drowsiness and affect the ability to drive or operate machinery; it aggravates symptoms of prostatism and keratoconjunctivitis sicca. It may precipitate acute glaucoma and may lower seizure threshold. Long-term high doses should not be abruptly discontinued; use with caution in patients with a history of hyperthyroidism, renal or hepatic impairment, or cardiac conduction disturbances. Avoid in elderly if possible (increased sedation, orthostasis, falls).
Pregnancy Risk: C
Adverse Effects
Common: Sedation and anticholinergic effects (dry eyes and mouth, blurred vision, constipation, difficulty with urination) are common; tolerance often occurs with continued use.
Less common: Postural hypotension, restlessness, tremor, parkinsonian syndrome, insomnia, rash
Rarely: Agranulocytosis, hepatic dysfunction, alopecia, arrhythmias, breast enlargement
Drug Interactions
Alcohol and CNS depressants: Effect of tricyclics is potentiated.
Cimetidine, methylphenidate, many SSRIs, ritonavir, indinavir, diltiazem, verapamil and cytochrome P450 2D6 inhibitors such as buproprion: Inhibit metabolism of tricyclics; dose reduction may be required
MAOIs: Increased risk of hypertensive crises; deaths have been reported
Sympathomimetics: Tricyclics potentiate effect
Clonidine: Amitriptyline inhibits hypotensive effects
Warfarin: Prothrombin time may be prolonged
Drugs that prolong QT interval: Increased risk of arrhythmia
Patient Instructions: Avoid alcohol use; may cause drowsiness
Clinical Pharmacology: Well absorbed, hepatic metabolism with renal excretion of metabolites; onset of antidepressant effects slow (2–4 weeks)
Adapted from: RheumaKnowledgy