Comparison of Botox with a Chinese type A botulinum toxin.

OBJECTIVE: To confirm and compare the therapeutic efficacies and remote effects of a Chinese type A botulinum toxin (CBTX-A, Lanzhou Biological Products Institute, China) and Botox (Allergan Inc., USA) for focal dystonia and muscle spasm.

METHODS: Prospective open study was conducted over 4 years for focal dystonia and muscle spasm. We enrolled 785 patients: 192 were injected with Botox and 593 with CBTX-A. They were followed for 3 to 48 months. Meanwhile single fiber electromyography (SFEMG) was performed in a subset of 40 patients before, 2-3 weeks, 5-8 weeks and 4-5 months after injection of Botox or CBTX-A.

RESULTS: There were no significant differences in clinical effects from two preparations, including the latency of response, maximal benefit and duration of improvement. The dose of the Chinese preparation which produced effects similar to Botox was higher. A significant increase in jitter was demonstrated 2-3 weeks after injection in both groups and fiber density values increased at the same time or later and remained 4-5 months after injections.

CONCLUSION: Both preparation are safe and effective treatments for patients with focal dystonia and muscle spasm. They both have subclinical effects on neuromuscular transmission of remote uninjected muscles. The Chinese preparation is a little less powerful but much cheaper than Botox.