Adverse events associated with nifurtimox treatment for Chagas disease in children and adults

BACKGROUND: Nifurtimox (NF) is one of the only two drugs currently available for Chagas disease (ChD) treatment. However, there is scarce data on NF safety, and many physicians defer or refuse NF treatment because of concerns about drug tolerance. METHODS: Prospective cohort study with retrospective data collection of adverse drug reactions (ADRs) associated with NF treatment of ChD. Children received NF doses of 10-15 mg/kg/day for 60-90 days, and adults 8-10 mg/kg/day for 30 days. RESULTS: 215 children (median age: 2.6yrs, range 0-17) and 105 adults (median age: 34yrs, range 18-57) were enrolled. Overall, 127/320 (39.7%) patients developed ADRs, with an incidence of 64/105 in adults, and 63/215 in children (OR = 3.7, 95%CI [2.2;6.3]). We observed 215 ADRs, 131 in adults (median: 2 events/patient (IQR25-75= 1-3) and 84 in children (median: 1 event/patient (IQR25-75= 1-1.5) (Wilcoxon-Test, PAdjusted < 8.10-5). ADRs were mainly mild and moderate. Severe ADRs were infrequent (1.2% in children and 0.9% in adults). Nutritional, central nervous and digestive systems were the most frequently affected, without differences between both groups. Treatment was discontinued in 31/320 (9.7%) patients without differences between groups. However, ADR-related discontinuations occurred more frequently in adults than in children (OR = 5.5, 95%CI = [1.5;24]).