Sulfamethoxazole dosage in monitoring the treatment of paracoccidioidomycosis patients treated with cotrimoxazole.

Introduction. Paracoccidioidomycosis (PCM) is one of the major systemic mycoses in Brazil, caused by fungi of the genus Paracoccidioides. Trimethoprim-sulfamethoxazole, also called cotrimoxazole (CMX), one of the drugs most used in the PCM treatment, can be monitored by the serum dosage of the sulfamethoxazole (SMX). Objective. The objective of this study was to evaluate the impact of serum levels of SMX during treatment in PCM patients treated with CMX on clinical and serological response. Methods. Thirty-six patients with a confirmed diagnosis of PCM, attended by the Department of Infectious Diseases of University Hospital of Botucatu Medical School - UNESP, from 1996 to 2013, were selected for this study. Clinical and laboratory data were obtained from medical records. Patients underwent monthly SMX dosing until clinical cure (initial treatment) and every three months until serologic cure (complementary treatment) was achieved. It was considered as SMX adequate serum levels when 80% or more of the measurements reached desired therapeutic values (70 mg/mL for initial treatment and 50 mg/mL for complementary treatment). The continuous variables were presented in median, 1st and 3rd quartiles and analyzed by the Mann-Whitney test, with p values lower than 0.05 being considered significant. Results. The 36 patients received CMX throughout the treatment of PCM. There was no difference in time to reach clinical cure between patients with the acute form with adequate levels [176 days (141 - 201)] and inadequate sulfa [195 days (123 - 251); p = 0.59]. However, in patients with chronic form (CF), clinical cure was shorter in those with adequate levels [96 days (55 - 126)] than in inadequate [224 days (147-319); p = 0.002]. The time to reach serological cure was also shorter in patients with CF with adequate levels [313 days (240 - 825)] than those with inadequate levels [720 days (473 - 1598); p = 0.04]. Patients who presented more than 80% of SMX serum levels above 70 mg/mL at initial treatment reached earlier clinical cure than those with SMX levels between 50–70 mg/dL [126 days (77 – 159) vs. 201 days (173 – 236), p=0,02]. Conclusion. These findings demonstrate the great importance of serum monitoring of SMX levels during the PCM treatment with CMX for earlier clinical and serologic cure.

Sulfamethoxazole dosage in monitoring of the treatment of paracoccidioidomycosis patients treated with cotrimoxazole