Chronic migraine is a debilitating condition in which people experience headaches on more than 15 days per month.
In a 36-week randomised trial involving 282 patients, researchers compared the efficacy of daily topiramate, a first-line treatment for chronic migraine, with onabotulinumtoxinA (botox) injections in the head and neck muscles given every 12 weeks.
They found that significantly more patients had a ≥50% reduction in headache frequency at week 32 compared with baseline in the botox group than in the topiramate group (40.0% vs 12.0%). Patients in the botox group also experienced fewer treatment-related adverse events (17.7% vs 69.0%), and were less likely to withdraw because of adverse events (3.6% vs 50.7%).
The researchers, who presented the findings at the Congress of the International Headache Society in Vancouver (7–10 September 2017), said the results indicated botox had greater tolerability than topiramate, which could make it a more effective choice for chronic migraine
 Rothrock J, Manack Adams A, Jo E et al. A multicenter, prospective, randomized, open-label study to compare the efficacy, safety, and tolerability of onabotulinumtoxinA and topiramate for headache prophylaxis in adults with chronic migraine: the FORWARD study. Presented at: 18th Congress of the International Headache Society; 7–10 September 2017; Vancouver, Canada.