Drug reference

Benznidazole

Nitroimidazole · Antiprotozoal

NitroimidazoleAntiprotozoal

CDSCO approvedSchedule H

EXCRETION

—

not curated

INTERACTIONS

3 major

SEVERE in our sources

PREGNANCY

Trichomonas vaginalis

FDA category + note

Top interactions

AmprenavirSevereDatabaseDDInter
DisulfiramSevereDatabaseDDInter
EthanolSevereDatabaseDDInter

Mechanism

Benznidazole is a nitroheterocyclic drug used in the treatment of Chagas' disease, which is caused by the parasite Trypanosoma cruzi. It targets the invading metacyclic trypomastigotes that penetrate host cells and proliferate as amastigotes, aiming to eliminate parasite persistence linked to the disease's pathology.

Indications

Chagas' disease (Trypanosoma cruzi infection)American trypanosomiasis (Chagas disease) caused by T. cruziAcute T. cruzi infection (including congenital)Early chronic T. cruzi infection (patients <18 years of age)T. cruzi reactivation

Dosing

Adult: Few adverse effects occur initially, but the toxicity of stibogluconate increases over the course of therapy. Most common are gastrointestinal symptoms, fever, headache, myalgias, arthralgias, and rash. Intramuscular injections can be very painful and lead to sterile abscesses. Electrocardiographic changes may occur, most commonly Twave changes and QT prolongation.…
Pediatric: Age <12 years: 5–7.5 mg/kg per day in 2 doses for 30–60 days. Approved for children 2–12 years.

Pharmacokinetics

Onset

Absorbed rapidly, reaches peak plasma levels within 3 h

Half-life

12 h

Bioavailability

readily absorbed (highly lipophilic)

Metabolism

extensively metabolized

Excretion

only 5% of the dose is excreted unchanged in the urine

Side effects

Common

rashpruritusnausealeukopeniaparesthesiasgi upsetAllergic dermatitis (29–50%)Anorexia and weight loss (5–40%)Paresthesia (0–30%)Peripheral neuropathy (0–30%)Nausea and vomiting (0–5%)

Serious

Hypersensitivity reactions (dermatitis, fever, icterus, pulmonary infiltrates, anaphylaxis)
Nausea
Vomiting
Myalgia
Weakness
Urticarial dermatitis (30% of patients in first week)
Bone marrow suppression (early in therapy)
Peripheral neuropathy (after prolonged treatment)
GI symptoms (after prolonged treatment, leading to weight loss)
Leukopenia (<1%)
Thrombocytopenia (<1%)