A comparative study of oral acetylsalicyclic acid and metoprolol for the prophylactic treatment of migraine. A randomized, controlled, double-blind, parallel group phase III study

This study was a multinational, multicentre, double-blind, active controlle d phase III trial designed to investigate efficacy and safety of 300 mg ace tylsalicyclic acid (ASA) (n = 135) vs. 200 mg metoprolol (n = 135) in the p rophylaxis of migraine. In total 270 (51 male and 219 female) patients, age d 18-65 years, suffering between two and six migraine attacks per month wer e recruited. The main objective was to show equivalence with respect to eff icacy, defined as a 50% reduction in the rate of migraine attacks. A run-in phase was carried out with placebo for 4 weeks, followed by a 16-week drug phase. In both treatment groups the median frequency of migraine attacks i mproved during the study period, from three to two in the ASA group and fro m three to one in the metoprolol group; 45.2% of all metoprolol patients we re responders compared with 29.6% with ASA. Medication-related adverse even ts were less frequent in the ASA group (37) than in the metoprolol group (7 3). The findings from this trial show that metoprolol is superior to ASA fo r migraine prophylaxis but has more side-effects. Acetylsalicylic acid is b etter tolerated than metoprolol. Using a strict responder criterion ASA sho wed a responder rate comparable with the placebo rate in the literature.