Amitriptyline may cause some people to be agitated, irritable, or display other abnormal behaviors. It may also cause some people to have suicidal thoughts and tendencies or to become more depressed. If you or your caregiver notice any of these adverse effects, tell your doctor right away. Amitriptyline is a tricyclic antidepressant used to treat depression and, off-label, conditions like insomnia, anxiety, migraines, and chronic pain. Amitriptyline Tablets Amitriptyline is a medication that treats depression. It works by increasing the amount of serotonin and norepinephrine in your brain. These hormones help regulate your mood. Brand names for this medication include Elavil® and Vanatrip®. Find out how amitriptyline treats pain and prevents migraine and how to take it. NHS medicines information on amitriptyline – what it's used for, side effects, dosage and who can take it. Amitriptyline is indicated for the treatment of major depressive disorder, neuropathic pain, and for the prevention of migraine and chronic tension headache. It can be used for the treatment of nocturnal enuresis in children older than 6 after other treatments have failed. [11] Learn about the side effects of amitriptyline, from common to rare, for consumers and healthcare professionals. Find patient medical information for Amitriptyline (Amitid, Elavil, Endep) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings.