Pharmacy & Therapeutics- August 2008 - (Page 480) CONTINUING EDUCATION CREDIT The Pharmacological Management Of Migraine, Part 2 Preventative Therapy George DeMaagd, PharmD, BCPS Educational Objectives After reviewing this article, readers should be able to: I Define preventative (prophylactic) pharmacotherapy and specify when it may be necessary in the treatment of migraine. I List the various preventative pharmacotherapies and their role in migraine management. I Describe the role of the various migraine pharmacotherapies for special populations, including children, pregnant women, and the elderly. I Describe the general pharmacological treatment pathway for the management of migraine. if they are experiencing two or more migraines per week, if their attacks last more than 48 hours, or if they have ineffective responses or contraindications to abortive therapy.1–5 Although numerous medications are used in the management of migraine (Table 1), the commonly used agents that have been studied and that have reported efficacy include the beta blockers, the tricyclic antidepressants, and some anticonvulsants.1 Beta-Adrenergic Blockers Beta blockers were first recognized in the 1960s as effective in migraine prophylaxis; by the 1970s, their use was well established, and they continue to be a treatment of choice.1,6–10 Their mechanism of action is not completely understood, although it may involve modulation of the adrenergic nervous system and an influence on cranial blood vessels.11–13 Beta blockers have been reported to be effective in approximately 70% of patients, with most data available for the nonselective agents propranolol (e.g., Inderal, Wyeth), timolol maleate (e.g., Blocadren, Merck), and nadolol (Corgard, King).14–27 Studies with propranolol reported efficacy with doses of 80 to 240 mg, with both regular-release and controlled-release formulations.6–10,14–19 Nadolol had similar efficacy, compared with propranolol, in doses of 20 to 120 mg when administered twice daily.20,21 Studies with other beta blockers, including some nonselective agents (e.g., timolol and bisoprolol)22,27 and the beta-1 selective agents (e.g., metoprolol [Toprol, AstraZeneca] and atenolol [Tenormin, AstraZeneca]) have also been reported to be effective. Beta-1 selective agents may be an appropriate option in patients with severe respiratory disease,23–26 but agents with intrinsic sympathomimetic activity should be avoided because of a lack of reported efficacy.11,13 Comparison trials with beta blockers and other preventative therapies, including valproic acid (Depakene, Abbott) and topiramate (Topamax, Ortho-McNeil), reported similar efficacy, with some data suggesting improved tolerability.28–33 Although beta blockers are usually well tolerated, reported side effects may include sedation, dizziness, vivid dreams, depression, fatigue, orthostatic hypotension, and impotence. Absolute contraindications include asthma, heart block, severe peripheral vascular disease, and Raynaud’s phenomenon.11 Important interactions involve other cardiovascular drugs that influence heart rate or blood pressure, including numer- This is part 2 of a two-part series. Introduction Migraine, its pathophysiology, and abortive (acute) pharmacotherapy were described in Part 1 of this two-part series in the July issue of P&T. Part 2 discusses the role of preventative (prophylactic) pharmacotherapy and the role of migraine treatments in special populations. It also provides an overview and guideline summary for general treatment pathways for the pharmacotherapy of migraine. Prophylactic Therapy Preventative migraine therapy refers to the daily administration of drug therapy for various periods, usually three to 12 months. The goals are to reduce the frequency and severity of attacks, to improve and reduce disability, and to minimize or eliminate the need for abortive drug therapy. Patients may be candidates for preventative therapy Dr. DeMaagd is Professor and Associate Dean of Academic Administration at Union University School of Pharmacy in Jackson, Tennessee. Accepted for continuing education credit April 10, 2008. 480 P&T® • August 2008 • Vol. 33 No. 8
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