Some studies have found parasitologic cure (a complete elimination of T. cruzi from the body) in children during the early stage of the chronic phase, but overall failure rate in chronically infected individuals is typically above 80%.Some studies indicate treatment with benznidazole during the chronic phase, even if incapable of producing parasitologic cure because it reduces electrocardiographic changes and delays worsening of the clinical condition of the patient.Benznidazole has proven to be effective in the treatment of reactivated  T. cruzi  infections caused by immunosuppression, such as in people with AIDS or in those under immunosuppressive therapy related to organ transplants. Children
Benznidazole can be used in children, with the same 5–7 mg/kg per day weight-based dosing regimen that is used to treat adult infections. A formulation for children up to two years of age is available. It was added to the WHO Essential Medicines List for Children in 2013. Children are found to be at a lower risk of adverse events compared to adults, possibly due to increased hepatic clearance of the drug. The most prevalent adverse effects in children were found to be gastrointestinal, dermatologic, and neurologic in nature. However, the incidence of severe dermatologic and neurologic adverse events is lower in the pediatric population compared to adults. It use for Chagas in children was approved by the FDA in the US in 2017. Pregnant women
Studies in animals have shown that benznidazole can cross the placenta. Due to its potential for teratogenicity, use of benznidazole in pregnancy is not recommended.
Side effects
Side effects tend to be common and occur more frequently with increased age. The most common adverse reactions associated with benznidazole are allergic dermatitis and peripheral neuropathy. It is reported that up to 30% of people will experience dermatitis when starting treatment. Benznidazole may cause photosensitization of the skin, resulting in rashes. Rashes usually appear within the first 2 weeks of treatment and resolve over time. In rare instances, skin hypersensitivity can result in exfoliative skin eruptions, edema, and fever. Peripheral neuropathy may occur later on in the treatment course and is dose dependent. It is not permanent, but takes time to resolve.Other adverse reactions include anorexia, weight loss, nausea, vomiting, insomnia, and dysguesia, and bone marrow suppression. Gastrointestinal symptoms usually occur during the initial stages of treatment and resolves over time. Bone marrow suppression has been linked to the cumulative dose exposure. Contraindications
Benznidazole should not be used in people with severe liver and/or kidney disease. Pregnant women should not use benznidazole because it can cross the placenta and cause teratogenicity. Pharmacology
Mechanism of action
Benznidazole is a nitroimidazole antiparasitic with good activity against acute infection with Trypanosoma cruzi, commonly referred to as Chagas disease. Like other nitroimidazoles, benznidazoles main mechanism of action is to generate radical species which can damage the parasites DNA or cellular machinery. The mechanism by which nitroimidazoles do this seems to depend on whether or not oxygen is present.