Tolerance of oral oxybutynin in the treatment of hyperhidrosis.

Oral oxybutynin (OOx) is an effective and safe treatment for the treatment of hyperhidrosis (HH). However, in some patients a loss of efficacy during prolonged treatment has been observed. Analysis of these cases could enable us to identify patients susceptible to OOx tolerance. An alternative treatment might then be considered. To assess tolerance to OOx in the treatment of HH. Secondarily, to assess epidemiological data and the duration of efficacy, together with the probable causes of any loss in this respect. Retrospective study of patients who started treatment with OOx for HH during the period 2007 to 2017 and who either abandoned this treatment due to loss of efficacy or needed higher daily doses to maintain the initial efficacy. Epidemiological data were collected, the duration of the efficacy of OOx was recorded and the possible causes of loss of efficacy were considered. The development of tolerance was suspected in 18 patients (8.5%) of the 211 who had previously responded to OOx. Thirteen patients abandoned OOx due to its lack of efficacy and five had to increase the dose in order to maintain efficacy. In seven patients, tolerance to the drug appeared in the first year of treatment, while in the remaining 11, the tolerance appeared later. Most patients achieved and maintained good control of HH with long-term OOx. However, in some cases the efficacy of the drug decreases. The study analysis did not produce findings enabling us to predict a loss of treatment efficacy.

Long-term efficacy of photodynamic therapy with methyl aminolevulinate in treating Bowen's disease in clinical practice: A retrospective cohort study (2006-2017).

BACKGROUND: Photodynamic treatment with methyl aminolevulinate (MAL-PDT) is considered an effective and highly recommended treatment for Bowen's disease. However, its long-term efficacy remains to be established, as significant differences have been reported in this respect. OBJECTIVE: The aim of the present study was to describe the results of a retrospective analysis of patients with Bowen's disease treated with MAL-PDT during the period 2006-17 at the Costa del Sol Hospital (Marbella, Spain). MATERIAL AND METHODS: This study is based on a retrospective descriptive analysis of the clinical records of patients treated with MAL-PDT from June 2006 to September 2017. The analysis was based on calculating the mean and standard deviation values for the quantitative variables, and frequency distributions for the qualitative ones. The survival curves were plotted by the Kaplan-Meier method, and the log-rank test was used to assess differences in survival between groups. A cox regression analysis was performed to clarify the significant prognostic factors. RESULTS: A total of 537 tumours with histologically confirmed Bowen's disease were treated with MAL-PDT. Recurrence-free survival at one year was 88%, and at 5 years, 71%. Tumour size >300 mm2 (≥21 mm in diameter P = 0.019), its location in the upper extremities (P = 0.029) and patient's age <70 years (P = 0.028) were all associated with an increased risk of recurrence. LIMITATIONS: Given the retrospective design of our study, the possible existence of information bias cannot be ruled out. CONCLUSIONS: Although it is an appropriate treatment option for patients with Bowen's disease, MAL-PDT presents a risk of recurrence of almost 30% at 5 years. Larger lesions (>300 mm2 ; ≥21 mm in diameter) are more likely to recur than smaller ones. Therefore, appropriate selection is needed of the tumour to be treated, and prolonged follow-up should be provided.