The first placebo-controlled trial of a special butterbur root extract for the prevention of migraine: Reanalysis of efficacy criteria

This is an independent reanalysis of a randomised, placebo-controlled parallel-group study on the efficacy and tolerability of a special butterbur root extract (Petadolex(R)) for the prophylaxis of migraine. The original protocol and analysis had a number of major shortcomings. In order to follow regulatory requirements, an independent reanalysis of the original data was performed. Following a 4-week baseline phase, 33 patients were randomised to treatment with two capsules 25 mg butterbur twice a day and 27 to placebo. The mean attack frequency per month decreased from 3.4 at baseline to 1.8 after 3 months (p = 0.0024) in the verum group and from 2.9 to 2.6 in the placebo group (n.s.). The responder rate (improvement of migraine frequency greater than or equal to50%) was 45% in the verum group and 15% in the placebo group. Butterbur was well tolerated. This small trial indicates that butterbur may be effective in the prophylaxis of migraine. Copyright (C) 2004 S. Karger AG, Basel.