Amitriptyline comes as a tablet to take by mouth. It is usually taken one to four times a day. Take amitriptyline at around the same time(s) every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take amitriptyline exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor. Your doctor will probably start you on a low dose of amitriptyline and gradually increase your dose. It may take a few weeks or longer before you feel the full benefit of amitriptyline. Continue to take amitriptyline even if you feel well. Do not stop taking amitriptyline without talking to your doctor. If you suddenly stop taking amitriptyline, you may experience withdrawal symptoms such as nausea, headache, and lack of energy. Your doctor will probably decrease your dose gradually.