Objective. The aim of the study was to investigate the efficacy, safety, and clinical features of the use of botulinum toxin type A injections (Relatox, JSC NPO Mikrogen, Russian Federation) for the treatment of chronic migraine in the routine practice of a specialized headache center. Material and methods. The open-label, retrospective, non-comparative study included 150 patients with a mean age of 39.0±12.9 years. Forty percent of patients were non-responders to two or more classes of migraine prophylaxis medications. Relatox was administered at doses of 155—195 U according to the PREEMPT (75.3%, n=113) or «Follow the Pain» (24.7%, n=37) protocols every 12 weeks. Results. Before treatment, the average number of days with migraine in the study group was 24.4±5.7, whereas after 12 weeks the number of days with migraine became 14.3±9.5 (p<0.001). The proportion of patients with ≥30% reduction in days with migraine after 12 weeks of therapy was 61.3% (n=92), with ≥50% reduction — 48.0% (n=72), with ≥75% reduction — 20.7% (n=31). Adverse events were reported in 3.3% (n=5): chewing difficulties (n=2), mild ptosis (n=1), neck muscle weakness (n=1), and flu-like symptoms (n=1). Conclusion. A real-world clinical trial confirmed the efficacy and safety of Relatox for the treatment of chronic migraine. The cumulative effect of Relatox was noted: an increase in effectiveness while following the protocol of administration once every 12 weeks.
Azimova et al. (Tue,) studied this question.