New topical treatment shows promise in primary palmar hyperhidrosis

Key takeaways:

• Topical 20% oxybutynin hydrochloride responder rates were significantly higher than placebo’s (52%.8% vs. 24.3%).
• The drug showed a favorable safety profile.

Topical 20% oxybutynin hydrochloride proved superior to placebo and demonstrated a favorable safety profile in the treatment of primary palmar hyperhidrosis, according to a phase 3 study.

Primary palmar hyperhidrosis (PPHH) is a condition characterized as excessive sweating on the palms that is not induced by temperature but by mental stress, emotional stimuli and physiological stimuli, according to Tomoko Fujimoto, MD, PhD, of the Ikebukuro Nishiguchi Fukurou Dermatology Clinic in Tokyo, and colleagues.

“Patients with PPHH have an impaired quality of life because the condition causes difficulties in handling paper documents, holding onto objects with the hands or touching other people (eg, shaking hands) in work and school life,” the researchers wrote.

Treatment options for PPHH come with many disadvantages including lack of insurance coverage, skin irritation, pain and other adverse effects. Topical 20% oxybutynin hydrochloride lotion (20% OL) is emerging as a possible treatment.

In this randomized, controlled phase 3 trial, Fujimoto and colleagues evaluated the efficacy of 20% OL in reducing sweat volume for the treatment of PPHH.

The study included patients aged 12 years and older from 21 clinics in Japan between Oct. 19, 2020, to Feb. 13, 2021. Patients were randomly assigned to receive 20% OL (n = 144; mean age, 34.1 years; 56.3% male) or placebo (n = 140; mean age, 35.7 years; 62.1% male) on both palms once daily for 4 weeks. The primary endpoint was defined as a sweat volume reduction of at least 50% from baseline, which was measured by ventilated capsule method. Secondary endpoints included sweat volume absolute and percentage changes from baseline, Hyperhidrosis Disease Severity Scale (HDSS) scores and Dermatology Life Quality Index (DLQI) scores.

Results showed that at the end of 4 weeks, the responder rate for sweat volume was 52.8% in patients treated with 20% OL compared with 24.3% in patients treated with placebo (treatment difference, 28.5%; 95% CI, 17.7%-39.3%; P < .001).

As early as week 2, responder rates of 1-point improvement or greater in HDSS scores were also higher in the 20% OL arm at 42.4% compared with 25.7% in placebo (treatment difference, 16.6%; 95% CI, 4.9-27.9; P = .0039). This difference extended to week 4, with 67.4% of the treatment group vs. 42.9% of the placebo group experiencing an HDSS improvement of 1 point or greater (treatment difference, 24.5%; 95% CI, 12.8-35.5; P < .001).

The DLQI was not significantly different between groups, but the authors theorized this may be due to the lack of prolonged treatment.

The study did not report any serious adverse events. Most adverse events in the treatment group were mild (21.5%), with 1.4% considered moderate.

“When administered for 4 weeks, 20% OL is effective for the treatment of PPHH and has a favorable safety profile,” Fujimoto wrote. “Therefore, it may represent a promising treatment option.”