I started taking 50mg Amitriptyline for fibromyalgia, and having suffered insomia for years I thought it was great. I managed to cut it down after a few weeks to 25mg. Unfortunately after 4-6 weeks it didnt seem to have any effect so I increased to 50mg again. Now I find even this higher dose is not working. I am reluctant to increase again. Has anyone else had this problem with amitriptyline?.