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 (PPH); 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 sequencing administration of oral oxybutynin chloride after BTX-A injections vs oral oxybutynin chloride in monotherapy in patients with PPH. Secondary aim is to evaluate if the sequencing approach can allow the control of hyperhidrosis with lower dose of oral oxybutynin. Patients enrolled 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 Life Quality Index (DLQI) score; safety was assessed through collection of the adverse events reported by patients both at baseline, at 24 and 52 weeks. Patients receiving sequencing treatment showed significant greater improvement than patients receiving oxybutynin chloride alone at T24 (HDSS P = .0076 and DLQI P = .0139) and T52 (HDSS P = .0387 and DLQI P = .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 = .001), than patients receiving monotherapy (P = .04). A sequencing therapeutic approach to palmar hyperhidrosis increases 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.