Mechanism of Action

Amitriptyline affects serotonin and noradrenaline reuptake almost equally.

Uses

Approved

Amitriptyline is approved for the treatment of endogenous depression and involutional melancholia (depression of late life, which is no longer seen as a disease in its own right), and reactive depression and for depression secondary to alcoholism and schizophrenia. Adult typical dosages are 75 to 200mg daily, with half this initially for elderly or adolescents.

It may also be used to treat nocturnal enuresis (bed wetting). Children between the ages of 7 to 10 years having a dose of 10 to 20 mg, older children 25 to 50mg at night. It should be gradually withdrawn at the end of the course, which overall should be of no more than 3 months.

Unapproved/Off-Label/Investigational

Amitriptyline may be prescribed for other conditions such insomnia, migraine, rebound headache, chronic pain, postherpetic neuralgia (persistent pain following a shingles attack), fibromyalgia, vulvodynia, interstitial cystitis, irritable bowel syndrome and as a preventative (prophylaxis) for patients with frequent migraines. Typically lower dosages are required for pain modification of 10 to 50mg daily.

A randomized controlled trial published in June of 2005 found that amitriptyline was effective in functional dyspepsia refractory to famotidine and mosapride combination therapy.

Overdose

The symptoms and the treatment of an overdose are largely the same as for the other tricyclic antidepressants.