Combined treatment of palmar hyperhidrosis with botulinum toxin type A and oxybutynin chloride: results of a clinical, multicenter, prospective study.

Oxybutynin chloride and Botulinum Toxin type A (BTX-A) have demonstrated to be effective treatments for primary palmar hyperhidrosis, however both of them are not completely free from local and/or generalized side effects. Primary aim of this study is to compare efficacy and safety of a therapeutic approach based on in sequence administration of oral oxybutynin chloride following BTX-A injections versus oral oxybutynin chloride in monotherapy in patients with primary palmar hyperhidrosis. Secondary aim of the study is to evaluate if the sequencing approach can allow the control of hyperhidrosis with lower dose of oral oxybutynin, thus reducing the related side effects. Patients with primary focal palmar hyperhidrosis receiving sequencing treatment with BTX-A injections followed by oral oxybutynin chloride administration and patients in monotherapy with oral oxybutynin chloride were compared for short and long term efficacy and safety of treatments. Effectiveness was evaluated through the Hyperhidrosis Disease Severity Scale (HDSS), and the Dermatology Quality of Life Index (DLQI) score; safety was assessed through collection of the adverse events (AEs) reported by patients both at baseline, at 24 weeks and 52 weeks after starting the treatments in both groups. Patients receiving sequencing treatment showed significant greater improvement than patients receiving oxybutynin chloride alone at T24 (HDSS p=0.0076 and DLQI p=0.0139) and T52 (HDSS p=0.0387 and DLQI p=0.0087). The dose of oxybutynin chloride useful to control hyperhidrosis was lower, and retention rate to the treatment was higher in patients receiving sequencing treatment (p=0.001), than patients receiving monotherapy with oxybutynin chloride alone (p=0.04). A sequencing therapeutic approach to palmar hyperhidrosis provides good clinical results, increasing both efficacy and safety compared with the use of oral oxybutynin chloride alone, and allows clinicians to keep lower dosage of oxybutynin chloride reducing generalized side effects and increasing the retention rate to the treatment. This article is protected by copyright. All rights reserved.