Topical Oxybutynin for Treatment of Hyperidrosis: Local or Systemic Effect?

Background: Anticholinergics, both orally and topically, have been shown to enhance quality of life and reduce sweat in patients with hyperhidrosis, potentially obviating the need for surgical interventions. However, it remains unclear whether topical application specifically exerts local or systemic effects in patients with axillary hyperhidrosis. This study's primary aim is to assess topical oxybutynin's impact on axillary hyperhidrosis. Study Design: Twenty patients (initially planned sample size) diagnosed with axillary hyperhidrosis will be randomized into three groups. Group A will receive 2.5 mg of oral oxybutynin once daily at night for the first seven days, 2.5 mg twice daily from the 8th to the 21st day, and 5 mg twice daily from the 22nd to the 35th day. Group B will be administered a topical placebo as an oxybutynin spray, applying two sprays to each axilla twice daily for 35 days. Group C will receive a 10% oxybutynin topical spray, also used with two sprays to each axilla twice daily over 35 days (investigational product). The primary efficacy outcome will be the evaluation of the effectiveness of topical oxybutynin spray in treating hyperhidrosis, assessed by the number of patients showing an improvement in the severity of their condition by day 35, as measured by the Hyperhidrosis Disease Severity Scale (HDSS). Safety will be assessed by adverse and severe adverse events during the treatment Summary: The TODAY trial will generate high-quality evidence on the effects of topical oxybutynin, assessing whether its impact is local or systemic in patients with axillary hyperhidrosis.