Population pharmacokinetic study of benznidazole in pediatric Chagas disease suggests efficacy despite lower plasma concentrations than in adults

PLoS Negl Trop Dis. 2014 May 22;8(5):e2907. doi: 10.1371/journal.pntd.0002907. eCollection 2014 May.


Introduction: Chagas disease, caused by the parasite Trypanosoma cruzi, can lead to long term cardiac morbidity. Treatment of children with benznidazole is effective, but no pediatric pharmacokinetics data are available and clinical pharmacology information on the drug is scarce.

Patients and methods: Prospective population pharmacokinetic (PK) cohort study in children 2-12 years old with Chagas disease treated with oral benznidazole 5-8 mg/kg/day BID for 60 days. (clinicaltrials.gov #NCT00699387).

Results: Forty children were enrolled in the study. Mean age was 7.3 years. A total of 117 samples were obtained from 38 patients for PK analysis. A one compartment model best fit the data. Weight-corrected clearance rate (CL/F) showed a good correlation with age, with younger patients having a significantly higher CL/F than older children and adults. Simulated median steady-state benznidazole concentrations, based on model parameters, were lower for children in our study than for adults and lowest for children under 7 years of age. Treatment was efficacious in the 37 patients who completed the treatment course, and well tolerated, with few, and mild, adverse drug reactions (ADRs).

Discussion: Observed benznidazole plasma concentrations in children were markedly lower than those previously reported in adults (treated with comparable mg/kg doses), possibly due to a higher CL/F in smaller children. These lower blood concentrations were nevertheless associated to a high therapeutic response in our cohort. Unlike adults, children have few adverse reactions to the drug, suggesting that there may be a direct correlation between drug concentrations and incidence of ADRs. Our results suggest that studies with lower doses in adults may be warranted.

Trial registration: ClinicalTrials.gov NCT00699387.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Chagas Disease / blood
  • Chagas Disease / drug therapy
  • Chagas Disease / metabolism*
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Linear Models
  • Male
  • Nitroimidazoles / adverse effects
  • Nitroimidazoles / blood*
  • Nitroimidazoles / pharmacokinetics*
  • Nitroimidazoles / therapeutic use
  • Trypanocidal Agents / adverse effects
  • Trypanocidal Agents / blood*
  • Trypanocidal Agents / pharmacokinetics*
  • Trypanocidal Agents / therapeutic use


  • Nitroimidazoles
  • Trypanocidal Agents
  • benzonidazole

Associated data

  • ClinicalTrials.gov/NCT00699387

Grants and funding

This study was supported by the Thrasher Research Fund Early Career Award (USA), Fundación Bunge y Born (Argentina), Ministry of Health, Buenos Aires City Government (Argentina), Hospital de Niños R Gutierrez, Buenos Aires (Argentina), and the Hospital for Sick Children, Toronto (Canada). The funding provided by the agencies mentioned in the cover page was unrestricted. These agencies had no access to the data, or the manuscript, had no influence and did not provide comments or guidance on the study or the manuscript. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.