A split-face study comparing the onset of action, change in degree of wrinkles, patient satisfaction, duration of effect and adverse effects of OnabotulinumtoxinA (ONA; Botox, Allergan, and AbobotulinumtoxinA (ABO; Dysport, Valeant Pharmaceuticals) has revealed subtle differences between the two popular injectables. Ramtin Kassir, MD, et al, treated 85 patients aged 18-75 with moderate to severe wrinkles in either the glabellar or crow’s feet area, or both. Patients who had conditions that would interefere with the assessment of wrinkles were excluded. These included patients who had undergone treatment with ABO or ONA in the preceding nine months, had surgery around the eye area, facial scars, thick sebaceous skin, dermatochalasis, neuromuscular disorders such as myasthenia gravis or multiple sclerosis, use of aminoglycoside or curare-like agents or a history of facial nerve palsy.
ABO and ONA were injected on opposite sides of the face—ABO injection on the right side of the face and ONA on the left for group one; and ONA injection on the right side of the face and ABO on the left for group two. Patient assessments were performed at two weeks, one month, three months, four months and five months post-treatment.
All patients showed onset of improvement in the glabellar area within five days of treatment with 28% reporting improvement within one day with ABO and 17% with ONA. On the second day 59% of patients treated with ABO showed improvement vs. 37% with ONA. On the third day, 85% of ABO-treated areas showed improvement vs. 70% with ONA. On day five,100% of treated areas were improved, leading the authors to conclude, “Time to onset was significantly quicker with ABO than ONA, with a mean difference of 0.52 days (P < 0.0001).”
In addition, evaluator assessment showed that 83% of ABO-treated areas continued to show improvement at four months vs. 48% with ONA in the glabellar area, and 65% with ABO vs. 47% with ONA at four months in the crow’s feet area. The published study appeared in Dermatology and Therapy (August 2013).