[Pharmacologic properties and results of a clinical study of oxybutynin hydrochloride lotion (APOHIDE® Lotion 20%) as a novel treatment for primary palmar hyperhidrosis].

APOHIDE_® Lotion 20% is a topical agent for treating primary palmar hyperhidrosis that contains the active ingredient oxybutynin hydrochloride. Oxybutynin hydrochloride has anticholinergic effects and inhibits sweating by binding to the M₃ receptor, a subtype of the muscarinic acetylcholine receptor, in eccrine sweat glands. The clinical response to oxybutynin hydrochloride treatment also involves N-desethyloxybutynin, an active metabolite of oxybutynin. A clinical study in Japanese patients with primary palmar hyperhidrosis showed superiority of APOHIDE_® Lotion 20% over placebo, i.e., there were significantly more responders (i.e., patients with a reduction in sweat volume ≥50% from baseline) in the APOHIDE_® Lotion 20% group (APOHIDE_® Lotion 20% group: 52.8%, placebo group: 24.3%; treatment difference: 28.5%; P < 0.001, Fisher's exact test). This and other clinical studies reported some adverse events (AEs) associated with the drug's anticholinergic effects and some application site AEs, but most of the AEs were mild. Clinical response did not decrease with long-term (52-week) treatment, and only a few patients (2 of 125) discontinued treatment because of AEs. Taken together, study results indicate that APOHIDE_® Lotion 20% may be an effective and safe new treatment option for patients with primary palmar hyperhidrosis.