Emir Ruşen1, Gaye Hafez2, Yeşim Tunç3

1Department of Neurology, Altınbaş University Medical Park Bahçelievler Hospital, Istanbul, Türkiye
2Department of Pharmacology, Faculty of Pharmacy, Altınbaş University, Istanbul, Türkiye
3Department of Statistics, Faculty of Medicine, Kütahya Health Sciences University, Kütahya, Türkiye

Keywords: Botulinum toxin, headache, migraine, Onabot-A, wear-off.


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.

Cite this article as: Ruşen E, Hafez G, Tunç Y. The wear-off phenomenon of repeated botulinum toxin injection for chronic migraine treatment: A retrospective study. Turk J Neurol 2024;30(1):47-55. doi: 10.55697/tnd.2024.18.

Data Sharing Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Ethics Committee Approval

The study protocol was approved by the Altınbaş University Clinical Research Ethics Committee (date: 08.12.2022, no: 162). The study was conducted in accordance with the principles of the Declaration of Helsinki.

Author Contributions

Did the literature research: G.H.; Wrote the manuscript: E.R., G.H.; Analysed the statistical calculations, all the authors contributed to writing, editing and reviewing the manuscript: Y.T.

Conflict of Interest

The authors declared no conflicts of interest with respect to the authorship and/or publication of this article.

Financial Disclosure

The authors received no financial support for the research and/or authorship of this article.


Thanks to the Altınbaş University Medical Park Bahçelievler Hospital, Neurology Clinics staff during the follow-up of the patients.