Frozen versus fresh reconstituted botox for laryngeal dystonia.

OBJECTIVES: To compare the efficacy and side effects of frozen versus fresh reconstituted botulinum toxin type A (BTX-A) in the treatment of laryngeal dystonia.

STUDY DESIGN AND SETTING: Prospective open-label crossover study; 43 adult patients with adductor spasmodic dysphonia were randomly treated with fresh or refrozen reconstituted BTX-A at a private voice center. Treatment outcomes were assessed by duration of action and self-rated satisfaction (7 point Likert scale). Side effects of breathiness and dysphagia for liquids were assessed as well.

RESULTS: There was no statistically significant difference in the duration of action (mean, 16.2 +/- 8.5 vs 16.0 +/- 7.6 weeks) and self-rated satisfaction of the treatment (median, 6.0 vs 6.0 points). The side effects were similar for both BTX-A injection types. In addition, there were no instances of infection for refrozen injections.

CONCLUSIONS: BTX-A may be safely used after being reconstituted and frozen or refrozen without a significant loss of effectiveness or additional side effects. In our experience, the period of freezing was on 2 occasions for up to 8 weeks.

SIGNIFICANCE: Refrozen BTX-A may be a cost-effective use of an expensive drug.

EBM RATING: B-2b.