Nifurtimox is a nitrofuran derivative used as a primary agent in the treatment of American trypanosomiasis (Chagas' disease) caused by Trypanosoma cruzi, especially in the acute, early stage of the disease. The efficacy of nifurtimox in the treatment of chronic Chagas' disease varies from one country to another, possibly due to variation in the sensitivity of different strains of the organism. 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. Nifurtimox forms a nitro-anion radical metabolite that reacts with nucleic acids of the parasite causing significant break down of DNA. Nifurtimox undergoes reduction and creates oxygen radicals such as superoxide. These radicals are toxic to T. cruzi. Mammalian cells are protected by the presence of catalase, glutathione, peroxidases, and superoxide dismutase. Accumulation of hydrogen peroxide to cytotoxic levels results in parasite death. Side effects occur following chronic administration, particularly in elderly people. Major toxicities include immediate hypersensitivities such as anaphylaxis and delayed hypersensitivity reaction involving icterus and dermatitis. Central nervous system disturbances and peripheral neuropathy may also occur.

Benznidazole is an antiparasitic medication used in first-line treatment of Chagas disease. Benznidazole is a nitroimidazole antiparasitic with good activity against acute infection with Trypanosoma cruzi, commonly referred to as Chagas disease. Like other nitroimidazoles, benznidazole's main mechanism of action is to generate radical species which can damage the parasite's DNA or cellular machinery. Under anaerobic conditions, the nitro group of nitroimidazoles is believed to be reduced by the pyruvate:ferredoxin oxidoreductase complex to create a reactive nitro radical species. The nitro radical can then either engage in other redox reactions directly or spontaneously give rise to a nitrite ion and imidazole radical instead. In mammals, the principal mediators of electron transport are NAD+/NADH and NADP+/NADPH, which have a more positive reduction potential and so will not reduce nitroimidazoles to the radical form. This limits the spectrum of activity of nitroimidazoles so that host cells and DNA are not also damaged. This mechanism has been well-established for 5-nitroimidazoles such as metronidazole, but it is unclear if the same mechanism can be expanded to 2-nitroimidazoles (including benznidazole). In the presence of oxygen, by contrast, any radical nitro compounds produced will be rapidly oxidized by molecular oxygen, yielding the original nitroimidazole compound and a superoxide anion in a process known as "futile cycling". In these cases, the generation of superoxide is believed to give rise to other reactive oxygen species. The degree of toxicity or mutagenicity produced by these oxygen radicals depends on cells' ability to detoxify superoxide radicals and other reactive oxygen species. In mammals, these radicals can be converted safely to hydrogen peroxide, meaning benznidazole has very limited direct toxicity to human cells. In Trypanosoma species, however, there is a reduced capacity to detoxify these radicals, which results in damage to the parasite's cellular machinery. Benznidazole has a significant activity during the acute phase of Chagas disease, with a therapeutical success rate up to 80%. Its curative capabilities during the chronic phase are, however, limited. Some studies have found parasitologic cure (a complete elimination of T. cruzi from the body) in pediatric and young patients during the early stage of the chronic phase, but overall failure rate in chronically infected individuals is typically above 80%. However, some studies indicate treatment with benznidazole during the chronic phase, even if incapable of producing parasitologic cure, because it reduces electrocardiographic changes and a delays worsening of the clinical condition of the patient. Side effects tend to be common and occur more frequently with increased age. The most common adverse reactions associated with benznidazole are allergic dermatitis and peripheral neuropathy. It is reported that up to 30% of people will experience dermatitis when starting treatment. Benznidazole may cause photosensitization of the skin, resulting in rashes. Rashes usually appear within the first 2 weeks of treatment and resolve over time. In rare instances, skin hypersensitivity can result in exfoliative skin eruptions, edema, and fever. Peripheral neuropathy may occur later on in the treatment course and is dose-dependent. Other adverse reactions include anorexia, weight loss, nausea, vomiting, insomnia, and dyslexia, and bone marrow suppression. Gastrointestinal symptoms usually occur during the initial stages of treatment and resolves over time. Bone marrow suppression has been linked to the cumulative dose exposure.

Eflornithine is a prescription drug indicated in the treatment of facial hirsutism (excessive hair growth). Eflornithine hydrochloride cream for topical application is intended for use in women suffering from facial hirsutism and is sold by Allergan, Inc. under the brand name Vaniqa. Besides being a non-mechanical and non-cosmetic treatment, eflornithine is the only non-hormonal and non-systemic prescription option available for women who suffer from facial hirsutism. Eflornithine for injection against sleeping sickness was manufactured by Sanofi Aventis and sold under the brand name Ornidyl in the USA. It is now discontinued. Eflornithine is on the World Health Organization's List of Essential Medicines. Eflornithine prevents hair growth by inhibiting the anagen phase of hair production. This occurs by eflornithine irreversibly binding (also called suicide inhibition) to ornithine decarboxylase (ODC) and physically preventing the natural substrate ornithine from accessing the active site.