Evaluation of the concomitant use of oral preventive treatments and OnabotulinumtoxinA in chronic migraine: the PREVENBOX study.

BACKGROUND: OnabotulinumtoxinA is an effective preventive treatment for chronic migraine. In chronic migraine, besides a reduction in headache frequency, a decreased reliance on oral prophylactics is also indicative of treatment effectiveness. This study aimed to quantify the change in the use of oral prophylactics after treatment with onabotulinumtoxinA in patients with chronic migraine. METHODS: This was a retrospective, multicentric, cross-sectional study. Patients with chronic migraine (ICHD-3b) that had been treated with onabotulinumtoxinA were enrolled consecutively. We collected parameters related to each patient's pre-treatment situation, as well as their current one, focusing on frequency and intensity of migraine, number of oral prophylactics and the respective cycle of onabotulinumtoxinA. Univariate and logistic regression analyses were performed. RESULTS: We included 542 patients. 90.0% were taking oral preventive treatments. During treatment with onabotulinumtoxinA, 47.8% withdrew at least one prophylactic and 41.6% stopped using oral prophylactics altogether. Factors associated with a reduction or cessations of oral prophylactics were: having>50% improvement in frequency and intensity, remission to episodic migraine, the use of topiramate as an initial treatment, an increased number of infiltrations and a shorter chronification period (p five cycles of onabotulinumtoxinA, >50% improvement in pain intensity and topiramate as an initial treatment were predictors of a reduction in oral prophylactics (AUC of 70.3%; p<0.001). CONCLUSIONS: Our study demonstrates the efficacy and safety of onabotulinumtoxinA. This treatment reduces the use of oral prophylactics. Withdrawal of oral prophylactics is most likely to occur after five cycles of treatment.