Long-term comparative pharmacovigilance of orally transmitted Chagas disease: first report

ABSTRACT

Background: Two old drugs are the only choice against Trypanosoma cruzi and little is known about their secondary effects in the acute stage of oral-transmitted Chagas disease (ChD).

Methods: A cross-sectional analytical surveillance study was conducted in a sizable cohort of patients seen during the largest acute foodborne ChD microepidemic registered so far. Individuals were treated with benznidazole (BNZ) or nifurtimox (NFX). ‘Common Terminology Criteria for Adverse Events’ was assessed to categorize side effects according to severity.

Results: Out of 176 treatments applied, 79% had one or more adverse effects, which predominated in adults (97.8%) as compared to children (75.5%). Risk of side effects with NFX was significantly higher than BNZ. Four adults and a child treated with NFX had severe side effects (pulmonary infarction, facial paralysis, neutropenia, blurred vision, bone marrow hypoplasia) warranting hospitalization, and drug suspension. Adverse effects frequently reported with NFX were abdominal pain, hyporexia, weight loss, headache, nausea and lymphocytosis, whereas skin rash, neurosensory effects, hyporexia, fatigue, pyrosis, abdominal pain and eosinophilia were observed with BNZ.

Conclusions: Frequency and severity of side effects during treatment of acute oral infection by T. cruzi demand direct supervision and close follow-up, even in those asymptomatic, to prevent life-threatening situations.

KEYWORDS:

• Chagas disease
• treatment
• side effects
• pharmacovigilance
• benznidazole
• nifurtimox

Declaration of interest

L Naranjo is an employee of GlaxoSmithKline. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Additional information

Funding

This work did not receive any financial support other than the own income of the authors’ place of work, the Sección de Inmnunología, Instituto de Medicina Tropical, Facultad de Medicina, Universidad Central de Venezuela (IMT-FM-UCV).