Objective.-To assess the efficacy and tolerability of topiramate for prophylaxis of migraine and cluster headache via a retrospective chart analysis. Background.-Topiramate has multiple mechanisms of action that could potentially contribute to migraine prophylaxis. We conducted a retrospective chart review to assess the efficacy of topiramate as add-on therapy in patients with transformed migraine or cluster headache, and as first-line therapy in patients with episodic migraine. Methods.-Patients diagnosed with transformed migraine, episodic migraine, or cluster headache, who received topiramate either as add-on therapy or monotherapy were selected via retrospective chart review. Patients had begun topiramate therapy at 25 mg/day for the first week and increased their dosage by 25 mg/week to a maximum of 200 mg/day. Topiramate was used as add-on therapy for patients with transformed migraine and cluster headache, and as a first-line monotherapy in patients with episodic migraine who had no previous prophylactic therapy. The outcome parameters examined included a mean 28-day migraine frequency, migraine severity, number of headache days/month, number of abortive medication tablets/month, patient global evaluation, and the MIDAS scale. Results.-One hundred seventy-eight patients (transformed migraine: n = 96; episodic migraine: n = 70; and cluster headache: n = 12) were included in the retrospective analysis. The mean dose of topiramate for all patients was 87.5 mg/day. For patients with transformed migraine, mean migraine frequency decreased from 6.3/28 days to 3.7 (P = 0.005). Mean severity decreased from 7.1 to 3.8 on a 10-point scale, with 10 representing the most severe pain (P = 0.003). The mean number of headache days/month decreased from 22.1 to 9.6 (P = 0.001), and the mean number of abortive medication tablets decreased from 28.7/month to 10.6 (P = 0.001). Patient global evaluation indicated substantial or moderate improvement in 53% of patients with transformed migraine who used topiramate as add-on therapy. Mean MIDAS scale values decreased from 90.2 to 24.9 (P<0.0001). The 70 episodic migraine patients who were administered topiramate as first-line therapy exhibited a decrease in mean migraine frequency (5.8/28 days to 1.9, P = 0.001), while mean migraine severity decreased from 8.1 to 2.0 (P = 0.003). Sixty-one percent of patients reported marked improvement. Nine of the 12 cluster headache patients exhibited substantial or moderate improvement in symptoms, whereas three had no improvement. The most common adverse effects were paresthesias (12%), cognitive effects (11%), and dizziness (6%). Eight patients discontinued topiramate due to adverse effects; cognitive effects were the most common reason. No patient discontinued topiramate treatment due to lack of efficacy. Twelve percent of patients lost more than 5 lbs during treatment (a range of 5-120 lbs). Conclusion.-For both patients with transformed migraine (add-on therapy) and patients with episodic migraine (first-line monotherapy), topiramate yielded significant reductions in migraine frequency, migraine severity, number of headache days/month, and use of abortive medications. Topiramate also appears to be well tolerated and useful in the adjunctive treatment of cluster headache. Prospective double-blind, placebo-controlled trials will be required to confirm our results.
