Nifurtimox forms a nitro-anion radical metabolite that reacts with nucleic acids of the parasite causing significant break down of DNA. Its mechanism is similar to that proposed for the antibacterial action of nitrofuran agents. Nifurtimox undergoes reduction and creates oxygen radicals such as superoxide. These radicals are toxic to T. cruzi. Mammalian cells are protected by presence of catalase, glutathione, peroxidases, and superoxide dismutase. Accumulation of hydrogen peroxide to cytotoxic levels results in parasite death.
Nifurtimox has been used to treat Chagas disease, when it is given for 30 to 60 days. However, long term use of Nifurtimox does increase chances of adverse events like gastrointestinal and neurological side effects. Due to the low tolerance and completion rate of Nifurtimox, benznidazole is now being more considered for those who have Chagas disease and require long term treatment.
Nifurtimox has also been used to treat African trypanosomiasis (sleeping sickness), and is active in the second stage of the disease (central nervous system involvement). When nifurtimox is given on its own, about half of all patients will relapse, but the combination of melarsoprol with nifurtimox appears to be efficacious. Trials are awaited comparing melarsoprol/nifurtimox against melarsoprol alone for African sleeping sickness.
Combination therapy with eflornithine and nifurtimox is safer and easier than treatment with eflornithine alone, and appears to be equally or more effective. It has been recommended as first-line treatment for second-stage African trypanosomiasis
Anorexia (50-60% can limit completion of therapy)
Frequency Not Defined
Pleural effusion (rare)
Adult Dosage Forms & Strengths
Pediatric Dosage Forms & Strengths
Gastrointestinal complaints include nausea, vomiting, abdominal pain, anorexia, and weight loss. Possible neurologic symptoms include insomnia, twitching, restlessness, paraesthesias, disorientation, and seizures. Rashes also occur. These symptoms generally disappear when the dosage is reduced or therapy is stopped.
Active or history of peripheral neuropathy
Active or history of seizures & cerebral impairment, such as behavioral disorders, epilepsy, or psychoses