Abstract
BACKGROUND AND OBJECTIVE: OnabotulinumtoxinA (BoNTA) is a relatively safe and effective treatment for chronic migraine. The local mode of action of BoNTA favors the combination of oral treatments with systemic action. However, little is known about the possible interactions with other preventive treatments. The objective of the study was to describe the use of oral preventive treatments in patients with chronic migraine treated with BoNTA in routine clinical care and discuss the tolerability and efficacy according to the presence or absence of concomitant oral treatments. METHODS: In this multicenter, observational, retrospective, cohort study, we collected data from patients with chronic migraine receiving prophylactic treatment with BoNTA. Patients were eligible if aged ≥18 years, diagnosed with chronic migraine according to the International Classification of Headache Disorders, Third Edition criteria, and treated with BoNTA according to the PREEMPT paradigm. We documented the proportion of patients with at least one concomitant treatment prescribed specifically for migraine (CT+M) and their side effects during four BoNTA treatment cycles. Additionally, we collected monthly headache days and monthly acute medication days from the patients' headache diaries. Patients with CT+M were compared to those without concomitant treatment (CT-) using a nonparametric approach. RESULTS: Our cohort included 181 patients taking BoNTA, of whom 77 (42.5%) received a CT+M. The most frequently prescribed concomitant treatments were antidepressants and antihypertensive drugs. Side effects in the CT+M group occurred in 14 patients (18.2%). Only in three of them (3.9%), the side effects had a significant interference with the patient's functioning (all in topiramate 200-mg/day users). Both CT+M and CT- groups had a significant reduction in monthly headache days of respectively - 6 (95% confidence interval - 9, - 3; p < 0.001; w = 0.200) during cycle 4 compared with baseline versus - 9 (95% confidence interval - 13, -6; p < 0.001; w = 0.469). However, the reduction in monthly headache days was significantly smaller in patients with CT+M after the fourth treatment cycle compared with patients with CT- (p = 0.004). CONCLUSIONS: Prescription of oral concomitant preventive treatment is common in patients with chronic migraine receiving BoNTA. We did not identify any unexpected safety or tolerability issues in patients receiving BoNTA and a CT+M. However, patients with a CT+M experienced a smaller reduction in monthly headache days when compared with those with CT-, which might be associated with a higher resistance to treatment in that subgroup of patients.