Botulinum toxin type A treatment of upper facial rhytids done safely, effectively in single session

Botulinum toxin type A (Botox Cosmetic, Allergan) can be used safely and effectively in a range of doses to simultaneously treat a spectrum of upper facial rhytids in adult women, but a higher dose provides more marked and more durable efficacy without compromising safety, according to the results of a dose-comparison study presented by Alastair Carruthers, M.D., and Jean Carruthers, M.D.

Women in the trial received a total of 16 injections each, including five for glabellar lines, five for forehead lines, and six for crow's feet (three injections/eye). There were 60 women who were randomized equally into three dosage groups: 2 U/injection, 4 U/injection, or 6 U/injection for total doses of 32 U, 64 U, or 96 U, respectively. Efficacy was assessed beginning at week 2 and then every four weeks thereafter, and data were reported for follow-up extending to 32 weeks.

In the primary efficacy analysis of Subject's Global Assessment of Improvement, 95 to 100 percent of patients in all groups were judged to be responders at week 2. However, by week 12 there were significant dose-related differences in the responder rates, and responses were sustained past 24 weeks only among women treated with the 6 U dose.

In addition, women receiving the highest dose benefited with a greater degree of improvement based on assessment of the proportions in each group exhibiting a >=75 or >=50 percent improvement.

The higher dose was also favored in the secondary efficacy analyses that included a trained observers' assessment of overall change in appearance, and the trained observers' and subjects' assessment of rhytids on the 4-point Facial Wrinkle Scale at maximum muscle contraction and repose.

Analyses of adverse event data collected at each visit showed no dose-related differences in either the incidence or type of adverse events reported.

"The safety and efficacy of botulinum toxin type A injection for the treatment of hyperfunctional facial lines have been demonstrated in numerous clinical trials, but many studies involve the treatment of a single facial area. The current study indicates simultaneous treatment of glabellar rhytids, crow's feet and horizontal forehead lines can be undertaken safely. However, the response is increasingly positive as the dose increases in the range of 2 to 6 U per injection site," Dr. Alastair Carruthers says.