Aspirin Resistance in Women With Migraine

To test the hypothesis that the rate of aspirin resistance is greater in women with episodic and chronic migraine than in women without migraine, a three-group, randomized, double-blind, placebo-controlled, crossover design will be used to test the effects of aspirin 81 mg on platelet reactivity. Subjects will be randomized to treatment order (A) aspirin 81 mg for 10-14 consecutive days followed by placebo for 10-14 consecutive days or (B) placebo for 10-14 consecutive days followed by aspirin 81 mg for 10-14 consecutive days. Other than treatment order, subjects will be treated equally. Study procedures will be performed at the University of Washington, and the duration of the study per subject will be approximately 28 days. Endpoints include: a) Aspirin Reaction Units (ARU) using a point-of-care assay (VerifyNow Aspirin™; Accumetrics, San Diego, CA); b) serum thromboxane B2; and c) percent platelet inhibition on aspirin. Assessment of adherence to study regimen will be assessed by serum salicylate, medication diaries, and pill counts. Data will also be collected on migraine frequency, burden, disability, and medications used to treat headache. Subjects will maintain a migraine diary for the duration of the study (28 days). The target sample will include women with episodic migraine (n=40; n=20 MA, n=20 MO), women with chronic migraine (n=40) and non-migraine controls (n=40). The specific aims of the study are as follows: * Compare the rate of aspirin resistance between women with and without migraine following 10-14 consecutive days of aspirin 81 mg treatment * Compare the rate of aspirin resistance between women who have episodic migraine and chronic migraine following 10-14 consecutive days of aspirin 81 mg treatment * Compare the rate of aspirin resistance between women who have migraine with aura (MA) and migraine without aura (MO) following 10-14 consecutive days of aspirin 81 mg or placebo treatment * Compare the rate of aspirin resistance between women who have migraine with high monthly migraine frequency and low monthly migraine frequency following 10-14 consecutive days of aspirin 81 mg treatment