Hi. It depends on type of headache for which it was prescribed. Usually sibelium or flunarazine is used in prophylaxis of migranous headache, not that effective in other forms of headache. Tryptomer or amitriptyline is used for psycho somatic causes of headache and used as a adjuvant in other forms of headache.. So to answer your question, discontinuation depends on type of headache and nature of episodes and severity. Usually if asymptomatic for more than 6 months they can be discontinued by taking half the dose over a week and then on alternate days for another week then stop.. However this is a general guideline, it has to be adapted according to many factors... I would strongly advise to meet your doctor and follow his prescription....