Have had migraine for over 40 years. Have been on 20 mg per day amitryptaline for about a month and it certainly helps with the headaches. I can cope with the constant drowsiness and the thirst, but the constipation is such a serious problem, I am beginning to think I will have to stop taking it. I have LOADS of fibre, fruit, dates and water (and, at the moment, Senokot) - all to no avail! Can anyone help, PLEASE?