Is Prophylactic Oxybutynin Safe and Effective in Reducing the Severity of Palmar Hyperhidrosis in Adults?

OBJECTIVE: The objective of this selective EBM review is to determine “Is prophylactic oxybutynin safe and effective in reducing the severity of palmar hyperhidrosis in adults?” STUDY DESIGN: This review is based on two randomized controlled trials (RCTs) and one non-randomized crossover study published in 2008, 2011, and 2012. The studies compared the safety and efficacy of oxybutynin in reducing the severity of palmar hyperhidrosis. DATA SOURCES: All articles used were published in English, in peer-reviewed journals, and found using PubMed, Ebscohost, and Cochrane Review databases. OUTCOMES MEASURED: For all studies, the safety and effectiveness of oxybutynin on palmer hyperhidrosis was evaluated using post-treatment clinical questionnaires. For one study, symptom improvement was quantitatively measured using Transepidermal Water Loss (TEWL) measurements pre- and post-treatment. RESULTS: Van Houte et al. (2008) found no statistical significance (p \u3e 0.05) in effectiveness of sweat inhibition with oxybutynin at doses of 7.5 mg and 15 mg per day. Conversely, the Wolosker et al. studies (2011, 2012) saw statistically significant improvement (\u3e80% of participants) in palmar hyperhidrosis symptoms (sudoresis) with the administration of oxybutynin at doses of 10 mg per day. None of the studies reported worsening symptoms with treatment. Noted side effects primarily included dry mouth, in which moderate to severe cases were reported in 34.8%-48.1% of participants. Despite the prevalence of dry mouth, it was not found to be an impeding factor in the use of oxybutynin for palmar hyperhidrosis. CONCLUSIONS: Results of two of the three studies demonstrate that 10 mg of daily oxybutynin is safe and effective in the prophylactic management of palmar hyperhidrosis in those diagnosed with generalized hyperhidrosis (GH). Further comparative studies are warranted to investigate whether the long-term use of oxybutynin results in continued symptom improvement or tachyphylaxis