Amitriptyline, sold under the brand name Elavil among others, is a tricyclic antidepressant primarily used to treat major depressive disorder, a variety of pain syndromes such as neuropathic pain, fibromyalgia, migraine and tension headaches.[10] Due to the frequency and prominence of side effects, amitriptyline is generally considered a second-line therapy for these indications.[11][12][13][14]

The most common side effects are dry mouth, drowsiness, dizziness, constipation, and weight gain. Of note is sexual dysfunction, observed primarily in males. Glaucoma, liver toxicity and abnormal heart rhythms are rare but serious side effects. Blood levels of amitriptyline vary significantly from one person to another,[15] and amitriptyline interacts with many other medications potentially aggravating its side effects.