Pooled Analysis of the Safety of Botulinum Toxin Type A in the Treatment of Poststroke Spasticity

Abstract

Turkel CC, Bowen B, Liu J, Brin MF. Pooled analysis of the safety of botulinum toxin type A in the treatment of poststroke spasticity. Objective To examine the safety of botulinum toxin type A (BTX-A). Design Analysis of pooled data of 9 double-blind, placebo-controlled studies of patients with spasticity after stroke. Setting University hospitals and specialty rehabilitation centers in the United States. Participants A total of 482 patients with upper-limb spasticity and 310 with lower-limb spasticity (overall mean age, 58y; 60% men). Intervention Treatment with BTX-A (n=534; 1–3 treatments; mean dose, 231U) or placebo (n=258). Main Outcome Measure Adverse events. Results Most patients (69%) received only 1 treatment with BTX-A. Patients were followed for a mean of 17.8 weeks (range, 0.1–44.7wk) after each treatment. A total of 352 (65.9%) patients in the BTX-A group and 163 (63.2%) in the placebo group reported at least 1 adverse event ( P=.475). The most frequent adverse events reported by patients (>5% but <10% in either group) were respiratory infection, seizures, incoordination, and injection site pain, none of which occurred at a significantly higher rate in the BTX-A group (all P>.05). The majority of adverse events were rated as mild or moderate in severity. Only nausea was reported at a significantly higher rate in the BTX-A group (12/534 [2.2%]) than the placebo group (0/258) ( P=.011); in contrast, injection site pain, chest pain, and allergic reaction were reported significantly more frequently in the placebo group. Conclusions BTX-A has an acceptable safety profile for treatment of patients with focal spasticity following stroke, a population in which adverse events and comorbidities are common.