[Current prospects of specific treatment of Chagas' disease].

The evolution of the specific treatment of Chagas' disease, including the numerous drugs tested, is briefly summarized. Since 1969 laboratory and clinical studies have persistently demonstrated that nifurtimox (NFX) and benznidazole (BNL) are the best agents for treating Trypanosoma cruzi human infection, even though they cannot be considered ideal drugs. The main indications for NFX and BNL are: acute phase of the infection, congenital form, reactivation associated with immunosuppression, recently acquired infection, mostly in children and young adults, and in transfusions and organ transplant situations. Both drugs may also be indicated for the treatment of some patients in the undetermined asymptomatic form of the chronic infection with mild heart involvement, or in clinical megaesophagus patients who previously need symptomatic treatment to ensure the appropriate absorption of the medication. The most used dosage schedules are: NFX for 60-90 days, 8-10 mg/kg/day in adults and < 15 mg/kg/day in children. BNL, for 60 days, 5 mg/kg/day in adults and < 10 mg/kg/day in children. Both drugs are taken orally and must be given divided into 2-3 fractions after meals. Both drugs are well tolerated by children, and particularly in the acute phase of the disease. Adverse reactions may be observed, i.e. disturbances associated to the digestive tract such as hyporexia, nausea, vomiting and loss of weight with NFX, and dermopathy and polyneuropathy, with BNL. The main limitations of both drugs are in the long course of administration and the occurrence of adverse side effects. A series of promising new drugs for the treatment of human Chagas' disease is being tested. Because the relative lack of interest of the pharmaceutical industry in the research for new drugs for the treatment of the parasitosis--which affects 16-18 million people in Latin America--Universities and Research Governmental Institution should stimulate the investigation for the development of new drugs and the clinical evaluation of drugs experimentally known and not yet tested.