Platelet Antagonists in Migraine Prophylaxis A Clinical Trial Using Aspirin and Dipyridamole

SYNOPSIS The platelet hyperaggregability of the migraine population has lead us to postulate that platelet antagonists might be effective in migraine prophylaxis. A double‐blind cross‐over study of aspirin, 325 mg BID, combined with dipyridamole, 25 mg TID, compared to placebo and pretreatment conditions was undertaken. Platelet aggregation studies were done during the three month active medication and placebo periods. In patients with platelet hyperaggregability significant improvement occurred in headache frequency, intensity, and limitation of activity with no change in headache duration. Regardless of platelet aggregability, the 25 patients comprising the total sample significantly improved as compared to placebo. Sixty‐eight percent of the patients tested reported subjective improvement while taking the active medication. No side effects related to the medication were reported and no patients, including those who withdrew from the study for other reasons, reported worsening of headache while on the active medication. Although the significance of platelet hyperaggregability in migraine patients, and the pharmacological effect of aspirin and dipyridamole on this, is unclear, these medications may have potential as a method of migraine prophylaxis.