Flunarizine vs. pizotifen in migraine prophylaxis: a review of comparative studies

Six double-blind studies have been published in which the efficacy of flunarizine and pizotifen were compared. In none of the studies were differences of statistical significance revealed for attack frequency. Secondary analysis of the three studies in which the same protocol was employed, using parametric tests on transformed data gave similar results. Pooling of the data in an attempt to enhance the power by enlarging the number of patients, actually decreased the power due to an increase in standard deviation.