Pharmacology · Class
Antitrypanosomals !
Drugs against trypanosomes: benznidazole and nifurtimox cure Chagas disease when given early; others treat African sleeping sickness.
Updated 2026-11-01
What they are
Antiprotozoal drugs against Trypanosoma cruzi (Chagas disease, endemic in Colombia and Latin America) and T. brucei (African sleeping sickness). Chagas disease has only two: benznidazole and nifurtimox.
Mechanism of action
Benznidazole (a nitroimidazole) and nifurtimox (a nitrofuran) are prodrugs: a parasite mitochondrial nitroreductase reduces them to radicals and reactive metabolites that damage the parasite's DNA, lipids and proteins. They act on blood trypomastigotes and tissue amastigotes.
Target: Parasite nitroreductase (activates the nitro drugs)
Drugs in this class
- BenznidazoleThe preferred drug for Chagas disease: it cures acute and congenital infection; its most typical adverse effect is…Trypanosoma cruzi type I nitroreductase (activates the prodrug)
- NifurtimoxOral nitrofuran for Chagas disease, the alternative to benznidazole; it often causes loss of appetite, weight loss and…Trypanosoma cruzi nitroreductase (activates the prodrug)
- PentamidineParenteral diamidine for Pneumocystis pneumonia, leishmaniasis and early sleeping sickness; it can cause severe…Several parasite targets (DNA, RNA, phospholipid and protein synthesis)
Others in the class
- Suramin sodium
- Melarsoprol
- Eflornithine
- Fexinidazole
Test yourself
Think of the answer, then tap the question to see it.
Which two drugs cure Chagas disease?
Benznidazole and nifurtimox, both nitro prodrugs activated by the parasite itself.
In which phase of Chagas disease do they work best?
In the acute phase, including congenital infection; in the chronic phase efficacy falls with years of infection.
Why are women of childbearing age with chronic Chagas disease treated?
To prevent them passing the parasite to their babies in a future pregnancy (congenital transmission).
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Chagas disease (also known as American trypanosomiasis) (World Health Organization, 2025); Clinical Care of Chagas Disease (Centers for Disease Control and Prevention (CDC), 2024); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 67 (McGraw Hill, 2023).
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Representative model, for educational purposes only.