Nifurtimox is a 5-nitrofuran and is used to treat diseases caused by trypanosomes including Chagas disease and sleeping sickness. It is given by mouth and not by injection. Nifurtimox has also been used to treat African trypanosomiasis, and is active in the second stage of the disease. 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. Nifurtimox is in a Phase II clinical trial for the treatment of pediatric neuroblastoma and medulloblastoma.