Antiprotozoal Drug: Nifurtimox

Nifurtimox

Nifurtimox (Lampit) is a nitrofuran derivative whose likely mechanism of action for killing of trypanosomes is through the production of activated forms of oxygen. Nifurtimox is reduced to the nitro anion radical, which reacts with oxygen to produce superoxide and hydrogen peroxide. The free radical metabolites, an absence of parasite catalase, and a peroxide deficiency lead to lipid peroxidation and cell damage. This production of acti-vated oxygen results in toxicity to the protozoal cells.

The drug is given orally and is well absorbed from the gastrointestinal tract. It is rapidly metabolized, and only low levels are found in blood and tissues. The drug is excreted in the urine, primarily in the form of metabolites.

Nifurtimox is trypanocidal and exerts an effect on the trypomastigote and amastigote forms of T. cruzi. It is effective in the treatment of the acute form of Chagas’ disease but is less effective once the disease be-comes chronic. The drug is moderately well tolerated, and treatment generally lasts 3 to 4 months. Cure rates of 80 to 90% have been reported. Since much of the tis-sue damage caused by the disease is irreversible, early diagnosis and treatment are important. Nifurtimox has also been used in T. gambiense infection with menin-goencephalopathic involvement.

Although side effects occur in approximately half the patients treated with nifurtimox, it is necessary to discontinue treatment in only a minority. Nausea, vom-iting, abdominal pain, skin rashes, headache, insomnia, convulsions, and myalgia all have been reported.