Case report/review of repurposing oxybutynin (an antimuscarinic) to treat excessive sweating in Parkinson's disease, showing symptomatic benefit but no evidence of disease modification.

Useful as a practical, low-risk symptomatic option for autonomic hyperhidrosis in PD, but of limited value for Parkinson's therapeutic discovery since it lacks mechanistic, biomarker, or neuroprotective relevance.

Not all medications arrive from a disciplined path of translational drug development; sometimes, the route of discovery involves serendipity. A drug developed for controlling urinary urgency, oxybutynin, is reviewed here as a highly effective treatment for excessive sweating (hyperhidrosis). Its use in Parkinson disease is described in a case report.