The wear-off phenomenon of repeated botulinum toxin injection for chronic migraine treatment: A retrospective study

Abstract

Objectives: This study aimed to evaluate the efficacy, predictors of response, clinical considerations, and analysis of patient-reported wear-off events during injection periods of onabotulinumtoxinA (Onabot-A). Patients and methods: This retrospective study was conducted with 30 adult chronic migraine patients (26 females, 4 males; mean age: 37.9±9.3 years; range, 24 to 72 years) followed between January 2017 and December 2022. All patients received Onabot-A injections at different frequencies throughout their treatment and responded to Onabot-A. The duration between cycles was 3 months in 26 patients, and this period varied in four patients. The Visual Analog Scale scores were measured before and after the injection, all patients responded to Onabot-A. Results: Nine patients stated that they experienced wear-off at least once during their treatment cycles. In some patients, the duration of action lasted less than 12 weeks, resulting in a wear-off phenomenon. Although sex and age were not significant variables in terms of the presence or absence of wear-off phenomenon, the number of Onabot-A injections (Onabot-A treatment cycles) among patients was found to be a statistically significant variable in terms of the presence of wear-off (p<0.011). Conclusion: Repeated treatments using Onabot-A appear to be safe and well-tolerated, but the effectiveness of the drug appears to be affected by wear-off phases that may occur during long-term treatment with Onabot-A.