Efficacy and safety of 40 mg/kg and 60 mg/kg single doses of praziquantel in the treatment of schistosomiasis

Abstract

The aim of this study was to compare the efficacy, safety and reinfection rates at 6 and 12 months after treatment of schistosomiasis with praziquantel 60 mg/kg single dose, as compared to the standard 40 mg/kg single dose regimen. A school-based randomized, double blind, experimental drug trial was implemented in Bunawan and Trento, in the province of Agusan del Sur, Philippines. The Kato Katz technique was used for quantitative assessment of Schistosoma japonicum infection. Follow-up visits were done 21, 180 and 360 days post-treatment. Efficacy, safety and reinfection rates of the two treatment regimens were compared using Student's t-test, Chi-square/Fisher's exact test and analysis of variance. There were 102 and 101 patients assigned to the 40 mg/kg and 60 mg/kg treatment groups, respectively. On day 21 post-treatment, 95% and 98.0% of the patients were cured, with egg reduction rates were of 99.9% and 99.99%, respectively. Remaining infections were of light intensity. On days 180 and 360, infection rates increased, with re-emergence of moderate and heavy intensity infections. On treatment day, the cumulative prevalence of adverse events in the 60 mg/kg treatment group was significantly higher than in the 40 mg/kg treatment group (P = 0.002). In conclusion, praziquantel 40 mg/kg and 60 mg/kg single dose therapy had comparable efficacy. A significantly higher prevalence of adverse events, mostly mild and transient, was observed in the 60 mg/kg regimen. The 40 mg/kg regimen is recommended for the treatment of schistosomiasis. High reinfection rates suggest the need to re-examine behavioral and environmental factors in the community.