RimabotulinumtoxinB vs. onabotulinumtoxinA for the treatment of forehead lines: an evaluator-blind, randomized, pilot study.

BACKGROUND: Optimum dose ratios of rimabotulinumtoxinB (BTX-B) and onabotulinumtoxinA (BTX-A) have not been determined for forehead wrinkles. OBJECTIVE: To compare the efficacy and safety of BTX-B and BTX-A for the treatment of forehead lines. METHODS: Twenty-two women (mean age, 40 years) with symmetrical moderate to severe forehead lines were randomized to receive single intramuscular injections of BTX-A and BTX-B on either side of the forehead, at a potency ratio of 1 : 70 or 1 : 100. Subjects were followed-up for 16 weeks. Four physicians evaluated patients' photographs according to the 4-point Facial Wrinkling Grade (FWG). Clinical Improvement Scale (CIS) was calculated by subtracting FWG score at each visit from that at baseline. Patient satisfaction scores and adverse events were also recorded. RESULTS: Both BTX-A and BTX-B were effective for the treatment of forehead lines. At both potency ratios, BTX-A had a longer duration of action than BTX-B, while BTX-B led to faster improvement than BTX-A. There was no significant difference in CIS between 700 U and 1000 U BTX-B treatments. Adverse effects were mild and transient. CONCLUSION: Both BTX-A and BTX-B were effective and well tolerated for the treatment of forehead wrinkles at potency ratios of 1 : 70 and 1 : 100.