Tolerance to nifurtimox and benznidazole in adult patients with chronic Chagas' disease

Background: Current options for Chagas' disease treatment are restricted to benznidazole and nifurtimox. To the best of our knowledge, no study has ever compared their tolerance in adults in a non-endemic country. Objectives: To compare the completion rates and drug tolerance in a cohort of patients treated according to current guidelines. Patients and methods: We analysed the medical records of all Chagas' disease patients aged 18years or over who started antiparasitic treatment at the Geneva University Hospitals, Switzerland, from 2008 to 2016. We recorded treatment duration and all adverse events. Results: We included 176 patients, 92 and 84 of whom received benznidazole or nifurtimox, respectively. The overall treatment completion rate was 62.5%, without a significant difference between the groups (P=0.436). Most patients (89.8%) suffered at least one adverse event. Those receiving nifurtimox had more events (6.2 versus 3.5, P<0.001). Mucocutaneous symptoms predominated in the benznidazole group, whereas digestive symptoms were most frequent with nifurtimox. Neuropsychiatric events frequently occurred in both groups, most notably in patients receiving nifurtimox. Arthralgia, dyspnoea, sensitive neuropathy and pruritus were independent predictors of treatment interruption. Conclusions: Currently recommended drug regimens for Chagas' disease are not well tolerated and entail frequent treatment discontinuation irrespective of the drug used. This highlights the need to improve treatment tolerance in adults with Chagas' disease with new therapeutic options.