Chagas disease medical therapy

Treatment
There are two approaches to therapy, both of which can be life saving:


 * antiparasitic treatment, to kill the parasite; and
 * symptomatic treatment, to manage the symptoms and signs of infection.

Medication for Chagas' disease is usually only effective when given during the acute stage of infection. The drugs of choice are azole or nitroderivatives such as benznidazole or nifurtimox (under an Investigational New Drug protocol from the CDC Drug Service), but resistance to these drugs has already been reported. Furthermore, these agents are very toxic and have many adverse effects, and cannot be taken without medical supervision. The antifungal agent Amphotericin B has been proposed as a second-line drug, but cost and this drug's relatively high toxicity have limited its use. Moreover, 10-year study of chronic administration of drugs in Brazil has revealed that current chemotherapy does not totally remove parasitemia. Thus, the decision about whether to use antiparasitic therapy should be individualized in consultation with an expert.

In the chronic stage, treatment involves managing the clinical manifestations of the disease, e.g., drugs and heart pacemaker for chronic heart failure and heart arryhthmias; surgery for megaintestine, etc., but the disease per se is not curable in this phase. Chronic heart disease caused by Chagas' disease is now a common reason for heart transplantation surgery. Until recently, however, Chagas' disease was considered a contraindication for the procedure, since the heart damage could recur as the parasite was expected to seize the opportunity provided by the immunosuppression that follows surgery. The research that changed the indication of the transplant procedure for Chagas' disease patients was conducted by Dr. Adib Jatene's group at the Heart Institute of the University of São Paulo, in São Paulo, Brazil. The research noted that survival rates in Chagas' patients can be significantly improved by using lower dosages of the immunosuppressant drug cyclosporin. Recently, direct stem cell therapy of the heart muscle using bone marrow cell transplantation has been shown to dramatically reduce risks of heart failure in Chagas patients. Patients have also been shown to benefit from the strict prevention of reinfection, though the reason for this is not yet clearly understood.

Some examples for the struggle for advances:
 * Use of oxidosqualene cyclase inhibitors and cysteine protease inhibitors has been found to cure experimental infections in animals.
 * Dermaseptins from frog species Phyllomedusa oreades and P. distincta. Anti-Trypanosoma cruzi activity without cytotoxicity to mammalian cells.
 * Design of inhibitors to enzymes involved in trypanothione metabolism, which is unique to the kinetoplastid group of parasites.
 * The sesquiterpene lactone dehydroleucodine (DhL) affects the growth of cultured epimastigotes of Trypanosoma cruzi
 * The genome of Trypanosoma cruzi has been sequenced. Proteins that are produced by the disease but not by humans have been identified as possible drug targets to defeat the disease.