Amitriptyline (Elavil)

Category:

• Miscellaneous

Description:

• Tricyclic antidepressant, anxiolytic, antineurolgic

Indications:

• Depression

• Chronic pain (chronic tension headache, migraine, diabetic neuropathy, cancer pain, postherpetic neuralgia)

Contraindications:

• Acute recovery phase of myocardial infarction

• Concurrent use of monoamine oxidase inhibitors

Precautions:

• Pregnancy category D; excreted into breast milk; effect on nursing infant unknown

• Suicidal patients, convulsive disorders, prostatic hypertrophy, psychiatric disease, sever depression, increased intra-ocular pressure, narrow-angle glaucoma, urinary retention, hepatic/renal disease, hyperthyroidism, elderly, abrupt discontinuation

Adverse Reactions (Side Effects):

• CNS: anxiety, confusion, dizziness, drowsiness, exra-pyridimal symptoms, insomnia, memory impairment, nervousness, nightmares, panic, stimulation, tremors, weakness

• CV: dysrhythmias, hypertension, orthostatic hypotension, palpitations, syncope, tachycardia

• EENT: blurred vision, mydriasis, nasal congestion, ophthalmoplegia, tinnitis

• GI: constipation, cramps, diarrhea, dry mouth, epigastric distress, hepatitis, increased appetite, jaundice, nausea, paralytic ileus, stomatitis, vomiting, weight gain

• HEME: agranulocytosis, eosinophilia, leukopenia, thrombocytopenia

• GU: urinary retention

• SKIN: photosensitivity, pruritis, rash, sweating, urticaria  

Dosage:

Administered orally (tablet) and intramuscularly (NEVER intravenously!)

• Adult dose: 

  • PO 50-100mg at bedtime, 

  • may increase to 200mg daily, not to exceed 300mg daily (chronic pain doses usually at lower end of range)

  • IM (do not administer IV) 20-30mg four times daily, or 80-120mg at bedtime

• Adolescent/geriatric: 

  • PO 30mg daily in divided doses

  • may be increase to 150mg daily

• Child dose:   

  • chronic pain management: 

    • PO 0.1 mg/kg/day in 3 divided doses initially

    • advance as tolerated over 2-3 weeks to 0.5-2 mg/kg at bedtime

  • depression: 

    • PO 1 mg/kg/day in 3 divided doses initially

    • increases to 1.5 mg/kg/day

Drug interactions: 

Numerous, most significantly:

• MAOI’s: (Monamine oxidase inhibitors)

  • excessive sympathetic response

  • mania

  • hyperpyrexia

• Epinephrine, norepinephrine: 

  • enhanced pressor response

• Guanethidine, guanadrel: 

  • inhibited antihypertensive response

• Ethanol: 

  • additive impairment of motor skills