Fifteen-year experience in treating blepharospasm with Botox or Dysport: same toxin, two drugs.

OBJECTIVES: To compare the clinical characteristics and the long-term outcome of a large series of patients with blepharospasm (BS) treated with the two most used brands of BoNT-A over the last 15 years.

METHODS: We have reviewed the clinical charts of 128 patients with BS who received botulinum neurotoxin (BoNT) in 1341 treatments (Botox in 1009, Dysport in 332) over the last 15 years.

RESULTS: Mean dose per session was 34U +/- 15 for Botox and 152U +/- 54 for Dysport. Mean latency of clinical effect was 4.5 +/- 4.6 days for Botox and 5.0 +/- 5.7 days for Dysport (P > 0.05). Mean duration of clinical improvement was higher for Dysport than Botox: 80.1 +/- 36.3 and 66.2 +/- 39.8 days, respectively (P < 0.01). In a six-point scale (0: no efficacy, 6: remission of BS), the mean efficacy of both treatments was 3.60 +/- 1.3; 3.51 +/- 1.4 (Botox) and 3.85 +/- 1.2 (Dysport), P < 0.01. The doses of Botox (beta = 0.40) and Dysport (beta = 0.16) were significantly increased over time. Side effects occurred in 325 out of 1341 treatments (24.2%): 21.8% of the patients who had received Botox, and in 31.6% of those who had received Dysport (P < 0.01).

CONCLUSIONS: Both brands are effective and safe in treating blepharospasm; efficacy is long lasting. The differences in outcome and side effects suggest that, albeit the active drug is the same, Botox and Dysport should be considered as two different drugs.