Adjusting oral oxybutynin medication for hyperhidrosis to reflect seasonal temperature variations.

Most studies of oral oxybutynin (OOx) for the treatment of hyperhidrosis (HH) have assumed a stable treatment protocol, without taking into account adverse effects (AE) or seasonal variations in temperature. The objective is to evaluate adjusting the dose of OOx according to the time of year. Prospective study of patients who began OOx for HH between 2007 and 2017, and maintained treatment for at least 1 year, with a progressively increasing dose was performed. All patients were recommended to vary the dose of medication according to the time of year. Baseline epidemiological data, the response to treatment and AE were analyzed. About 122 patients were included (average age of 33.8 years). Up to 60.7% varied the dose. Significantly better results were obtained in the group that varied the dose. Twenty patients suspended the treatment in winter. Among them the adjusted OR was 3.04 (95% CI 1.24-7.45) for an excellent response. The frequency of AE was 74.6% with no differences among groups. Most patients are able to control their HH without requiring the same dose of OOx throughout the year. Given that the possible AE of OOx are dose-dependent, it seems reasonable to vary it according to the time of year.