Eflornithine (difluoromethyl ornithine, Ornidyl) is a unique antiprotozoal agent in that its mode of action in-volves inhibition of a specific enzyme, ornithine decar-boxylase. In eukaryotes, decarboxylation of ornithine is required for biosynthesis of polyamines, which are im-portant in cell division and differentiation.
Eflornithine is given intravenously, and about 80% of the drug is excreted in the urine within 24 hours. It does not bind significantly to plasma proteins and has a terminal plasma half-life of about 3 hours. It crosses the blood-brain barrier and is one of the drugs of choice for treating the hemolymphatic and meningoencephalitic stage of T. brucei-gambiense. The most significant side effects are anemia and leukopenia. Oral therapy is as-sociated with considerable gastrointestinal toxicity. Diarrhea, thrombocytopenia, and seizures are occasion-ally reported.