Towards a dose optimisation of botulinum toxin therapy for axillary hyperhidrosis: comparison of different Botox(®) doses.

Botulinum toxin is considered the treatment of choice for axillary hyperhidrosis. Its dosing, however, varies widely. We wanted to study differences in efficacy and adverse effects when Botox(®) 100 MU (B100) or Botox(®) 50 MU (B50) per axilla is applied. In a prospective double blind intraindividual side to side comparison design, we studied 51 patients (38 females, 13 males, age 32.8 ± 13.0 years) with symmetric axillary hyperhidrosis receiving B100 bilaterally the baseline period (BP), B100 unilaterally and B50 contralaterally at direct comparison (DC) and B50 bilaterally during the extension period (EP). 90 % of the patients reported the overall therapeutic effect as 'excellent', 10 % as 'good' during throughout the study. The duration of the therapeutic effect until it began to decline was 3.2 ± 1.3 months at BP, 3.2 ± 1.1 months at DC and 3.3 ± 1.4 months at EP. At DC none of the patients reported side to side differences of the therapeutic effect with respect to onset latency, intensity and duration. Injection site pain was identical on both sides. The clinical examination at the time of the re-injections did not reveal any side differences of the therapeutic effect. Throughout the study none of the patients reported adverse effects. Data suggest that the therapeutic effect of Botox(®) saturates at B50. Higher Botox(®) doses seem not to be necessary thus reducing costs for the treatment substantially.