Reporting of adverse reactions to benznidazole: does medical expertise matter?

Chagas disease (CD), caused by the protozoan parasite Trypanosoma cruzi, was first described in 1909 (1, 2).CD remains a serious public health problem in Latin America and is currently the leading cause of sudden death, severe cardiac arrhythmias, and intractable hearth failure in the region (3, 4).In Argentina, about 1.6 million people are infected with the disease, with an estimated prevalence rate of 4.1 (5).For more than three decades, only two drugs (nifurtimox and benznidazole (BZN)) have been available and proved effective for the treatment of T. cruzi infections (4, 6).Though both drugs are associated with a high frequency of adverse drug reactions (ADRs) (6, 7), BZN is the preferred drug in Argentina (8).The incidence of ADRs during treatment with BZN increases with patient age, with 41.1% of ADRs occurring in CD pediatric ABSTRACT This study evaluated and compared follow-up and adverse drug reaction (ADR) reporting for Chagas disease (CD) patients treated with benznidazole (BZN) by two health teams with different levels of experience, using medical records for 204 patients participating in the first year of a scaled-up public health program for CD case detection and treatment conducted at all 46 primary health care centers in La Plata district, Buenos Aires, Argentina, in 2014.Both teams were experienced in CD patient management and trained in BZN administration, and included senior physicians, but one team had no experience in administering BZN while the other team had three years of experience due to their participation in the program's pilot project.Patients with positive serology for CD were treated with 5 mg/kg/day of BZN for 60 days.Patients' median age was 35 years and 84.3% were female.There was a statistically significant difference in the number of ADRs reported by the experienced versus the inexperienced health teams (18 versus 44 respectively; P < 0.001).Health team experience in administering BZN to CD patients, and treatment duration, were significantly associated with reporting of ADRs (adjusted odds ratios (aORs) 0.340 (95% confidence interval (CI): 0.177-0.652)and 0.967 (CI: 0.942-0.993)respectively).ADR reporting increased with patient age, occurring at the highest frequency (42.9%) in people 50+ years old.All treatment discontinuations (nine) occurred in patients followed up by the inexperienced health team.Level of experience in BZN administration to CD patients was significantly and inversely associated with frequency of ADR reports: inexperienced health team members tended to report more.