To determine the comparative efficacy of tap water iontophoresis to iontophoresis with the
anticholinergic glycopyrrolate, we undertook a single-blinded right-left comparison study in 20 patients with palmoplantar
hyperhidrosis. Most patients had their palms treated and one patient had the soles treated. We compared the duration of symptom relief following iontophoresis with
glycopyrrolate unilaterally to iontophoresis with
glycopyrrolate bilaterally. Patients filled in daily efficacy assessment cards. Each palm was rated as 'dry', 'slightly wet', 'moderately wet' or 'very wet'. Following treatment with unilateral tap water iontophoresis, unilateral
glycopyrrolate and bilateral
glycopyrrolate, patients reported hand dryness for a median of 3, 5 and 11 days, respectively. As the data was paired, treatment differences were analysed using a sign-rank test. Bilateral
glycopyrrolate was superior to both unilateral
glycopyrrolate and tap water in most patients. Unilateral
glycopyrrolate was superior to tap water in most patients. All differences between groups were found to be statistically significant. We postulate that the increased efficacy of bilateral
glycopyrrolate when compared with unilateral
glycopyrrolate relates to its systemic absorption. We conclude that
glycopyrrolate iontophoresis is more effective than tap water iontophoresis in the treatment of palmoplantar
hyperhidrosis and that
glycopyrrolate iontophoresis has both local and systemic effects on perspiration.