NEW YORK (Reuters Health) – Rizatriptan is effective for acute migraine in patients taking topiramate for migraine prophylaxis, and few experience adverse effects, according to a report in Headache online November 11. “These results are comparable with those from clinical trials in patients not using prophylaxis, suggesting that the use of topiramate does not affect the efficacy or tolerability of rizatriptan for acute migraine treatment,” the authors conclude. Dr. Tony W. Ho, with Merck Sharp & Dohme Corp. in North Wales, Pennsylvania, and colleagues explain that several trials have shown that the anticonvulsant topiramate reduces the frequency of migraines by up to 65% when taken prophylactically. However, there are limited data on the efficacy of triptans for acute attacks during prophylactic treatment. The team conducted a study involving 108 patients experiencing at least two migraine attacks a month despite taking a stable dose of topiramate. The participants treated three severe migraine attacks in crossover fashion -- twice with a 10-mg rizatriptan orally disintegrating tablet and once with a placebo tablet, in random order. Ultimately, 93 patients completed the study. The rate of pain relief at 2 hours was 55.0% with rizatriptan compared with 17.4% with placebo (p As for safety, 15.8% of patients reported adverse effects such as nausea, somnolence or dizziness with rizatriptan compared with 3.2% when taking the placebo tablet, Dr. Ho and colleagues found. “The study data appear to indicate that the response to rizatriptan among migraineurs taking topiramate is largely similar to that observed in the general migraine population,” they conclude. “Results of the current study demonstrate that treatment with rizatriptan is an effective option for managing migraine attacks in these patients.” Reference: Rizatriptan for Treatment of Acute Migraine in Patients Taking Topiramate for Migraine Prophylaxis Headache 2011.