Trimethoprim-sulfamethoxazole versus placebo to reduce the risk of recurrences of Toxoplasma gondii retinochoroiditis: randomized controlled clinical trial (ISROT)

Abstract

 

Purpose

 

To compare the effects of trimethoprim-sulfamethoxazole versus placebo in reducing the risk of recurrences of Toxoplasma gondii retinochoroiditis.

 

Methods

 

This study was a single-center, prospective randomized, double-masked, clinical trial. 81 patients from Campinas, Brazil, with active recurrent Toxoplasma gondii retinochoroiditis were included (a new focus of necrotizing retinochoroiditis with active inflammation either adjacent to or remote from preexisting retinochoroidal scars, with positive IgG for Toxoplasmosis). All patients were successfully treated with 1 tablet of trimethoprim-sulfamethoxazole (800mg/160mg) two times daily for 45 days. After that, two patients drop out of the study. The remaining patients were randomized to group 1 (Trimethoprim-sulfamethoxazole tablet every two days) or group 2 (identical placebo tablet every two days). Block randomization was performed (blocks of 4 patients, 2 in each group) with stratification by gender. The primary outcome was 6-months incidence of recurrent Toxoplasmosis retinochoroiditis, and the secondary outcome was 6-months change of best correct visual acuity/BCVA (ETDRS chart).

 

Results

 

A total of 79 patients completed the 6-months follow-up (Figure 1). Demographic data were comparable in the 2 groups (Table 1). The incidence of recurrent Toxoplasmosis retinochoroiditis was 0/40 (0%) at group 1 and 5/39 (12.8%) at group 2 (P = .026). The changes of BCVA were 19 SD 21 letters in group 1 and 20 SD 16 letters (P = .833). No significant adverse events (drug reactions) were registered.

 

Conclusions

 

Trimethoprim-sulfamethoxazole compared with placebo may reduce the recurrences of Toxoplasma gondii retinochoroiditis.

 

 

 

Keywords: 734 toxoplasmosis • 422 antibiotics/antifungals/antiparasitics