The purpose of this study is to evaluate the safety and efficacy of two doses of topiramate (100 and 200 mg daily) versus placebo and propranolol in the prevention of migraine. The study will also assess dose response relationship of topiramate, estimate the relative efficacy of topiramate versus propranolol in prevention of migraine, and evaluate the effect of migraine prevention with topiramate versus placebo on Health Related Quality of Life.

This is a randomized, double-blind, placebo-controlled, parallel-group, multicenter study to evaluate the efficacy and safety of two doses of topiramate versus placebo and propranolol in the prevention of migraine headaches. The study consists of 4 phases: Baseline Phase (evaluation of eligibility criteria and tapering of any migraine prophylaxis medications patients are taking), Core Double-Blind Phase (patients are randomized to receive either 100 milligrams[mg]/day topiramate, 200mg/day topiramate, 160mg/day propranolol or placebo for a total of 26 weeks), Blinded Extension Phase (patients continue the same dose of medication until the sponsor terminates the study or a patient withdraws from the study), and Taper/Exit Phase (medication of patients exiting from the study is tapered over 7 weeks). The primary hypothesis is that one or two topiramate doses (100, 200 mg/day) will be superior to placebo in the prophylaxis of migraine based on the change in the monthly (28 days) migraine period rate from the prospective Baseline Phase to the Core Double-Blind Phase. Oral medication (100 milligrams[mg]/day topiramate, 200mg/day topiramate, 160mg/day propranolol, or placebo) during the 26-weeks Core Double-Blind Phase. Doses may be continued until the termination of the study or withdrawal by the patients during the Blinded Extension Phase.

Inclusion Criteria:

• Medical history consistent with migraine with or without aura according to the International Headache Society (IHS) for at least 1 year prior to the study
• Between 3 to 12 migraine periods and no greater than 15 headache days (migraine and non-migraine) per month during the Baseline Phase
• No clinically significant abnormalities on neurological exams, electrocardiogram (ECG) or clinical laboratory test results at baseline
• Female patients must be postmenopausal for at least 1 year, surgically incapable of childbearing, practicing abstinence, or practicing an acceptable method of contraception (requires negative pregnancy test)

Exclusion Criteria:

• Patients with headaches other than migraine
• Patients with episodic tension or sinus headaches
• Onset of migraine after age of 50 years
• Patients who have failed more than two adequate regimens for migraine prophylaxis
• Patients who overuse pain medications or certain other medications