Amitriptyline

Amitriptyline, sold under the brand name Elavil among others, is a tricyclic antidepressant primarily used to treat major depressive disorder and a variety of pain syndromes from neuropathic pain to fibromyalgia to migraine and tension headaches. Due to the frequency and prominence of side effects, amitriptyline is generally considered a second-line therapy for these indications.The most common side effects are dry mouth, drowsiness, dizziness, constipation, and weight gain. [Source: Wikipedia ]