Drug Uses Amitriptyline is used for treating depression. It may also be used for other conditions as determined by your doctor. How to use Use Amitriptyline as directed by your doctor. Check the label on the medicine for exact dosing instructions. Amitriptyline comes with an additional patient information sheet called a Medication Guide. Read it carefully and reread it each time you get Amitriptyline refilled. Amitriptyline may be taken with food or on an empty stomach. Avoid eating or drinking grapefruit juice while taking Amitriptyline. Amitriptyline may take up to 30 days to control symptoms of depression. Continue to use Amitriptyline even if you feel well. Do not miss any doses. Drug Class and Mechanism Amitriptyline is a tricyclic antidepressant. How tricyclic antidepressants improve depression symptoms is not fully understood. They are thought to increase the activity of certain chemicals in the brain (norepinephrine, serotonin), which help improve mood. Missed Dose If you miss a dose of Amitriptyline and are using it regularly, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once. Storage Store Amitriptyline between 68 and 77 degrees F (20 and 25 degrees C). Brief storage at temperatures between 59 and 86 degrees F (15 and 30 degrees C) is permitted. Store away from heat, moisture, and light. Do not store in the bathroom. Keep Amitriptyline out of the reach of children and away from pets.