Pharmacology · Antitrypanosomals
Nifurtimox !
Oral nitrofuran for Chagas disease, the alternative to benznidazole; it often causes loss of appetite, weight loss and neurological symptoms.
Updated 2026-11-01
Mechanism of action
A nitrofuran that works as a prodrug. The trypanosome's mitochondrial nitroreductase reduces it to nitro radical anions that bind macromolecules, causing lipid peroxidation, membrane damage, enzyme inactivation and DNA damage. It acts on T. cruzi trypomastigotes and amastigotes and also on T. brucei.
- Enters the trypanosome as a nitrofuran prodrug
- Nitroreductase turns it into nitro radicals
- Lipid peroxidation and damage to DNA and enzymes
- Blood and tissue forms of the parasite die
Pharmacokinetics
- Absorption
- Well absorbed orally; given with food
- Distribution
- Crosses the blood-brain barrier in animals; may pass into breast milk
- Metabolism
- Rapid, extensive biotransformation, probably with a first-pass effect
- Elimination
- Almost none unchanged in urine; removed as metabolites
- Half-life
- Short, a few hours
Indications
- Acute or congenital Chagas disease Chagas disease →
- Chronic infection in children and women of childbearing age Chagas disease →
- Chronic Chagas disease in adults without advanced damage, to slow progression to cardiomyopathy Chagas cardiomyopathy →
- Late-stage African sleeping sickness caused by T. b. gambiense, combined with eflornithine
Adverse effects
Common
- Loss of appetite and weight loss, very characteristic
- Nausea, vomiting, abdominal pain and diarrhoea
- Headache, dizziness or vertigo
- Fever
- Muscle weakness and tremor
Contraindications
- Pregnancy
- Severe kidney or liver failure
- History of neurological or psychiatric disorders (seizures, brain injury, mental illness)
- Hypersensitivity to nifurtimox
Key interactions
- Alcohol
- Worsens adverse effects; avoided throughout treatment
What is monitored
- Weight and appetite at every visit
- Neurological symptoms and changes in mood or behaviour
- Pregnancy test before starting
- Kidney and liver function before treatment
Administration and safety
- Oral with food, as a long course (about two months).
- The scored tablets can be split or dissolved in water for patients who cannot swallow them; the mixture is given right away with food.
- May cause weakness or tremor: caution with driving or operating machinery.
Nursing care
- Before: pregnancy test and ask about seizures, brain injury or mental illness.
- Weigh the patient at every visit: weight loss is common, especially in adults.
- Watch for behaviour changes, insomnia, tingling in feet and hands, and signs of allergy.
- Teaching: avoid alcohol; contraception for women during treatment and for months after, and condoms for men whose partner could become pregnant.
- If the mother breastfeeds, watch the baby for vomiting, rash, poor appetite, fever or irritability.
Pregnancy and breastfeeding
Can cause fetal harm: a pregnancy test is done first and contraception is used during treatment and for several months after; it is not given in pregnancy.
Test yourself
Think of the answer, then tap the question to see it.
Which adverse effect is more typical of nifurtimox than of benznidazole?
Loss of appetite with weight loss, together with neurological and psychiatric symptoms.
Besides pregnancy and kidney or liver failure, in whom does WHO avoid nifurtimox?
People with neurological or psychiatric disorders.
Which drug is nifurtimox combined with for late-stage African sleeping sickness?
Eflornithine (the NECT combination) against T. b. gambiense.
Why is nifurtimox selective for the parasite?
Because a trypanosome nitroreductase activates it, generating nitro radicals inside the parasite itself.
Related drugs
Related conditions
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Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Nifurtimox: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2025); Chagas disease (also known as American trypanosomiasis) (World Health Organization, 2025); Clinical Care of Chagas Disease (Centers for Disease Control and Prevention (CDC), 2024); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 67 (McGraw Hill, 2023).
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