Frequently Asked Questions
23. Is there a cure for Chagas disease?
Treatment with benznidazole and nifurtimox drug is curative only in acute or early chronic infections, and in congenital cases. In general, treatment efficacy in the acute phase is 60-85%, and for congenital infection it is 90% when treated in the first year of life. Complete cure can be expected with immediate treatment of accidental infections.
Few studies support the use or benznidazole for chronic complications of Chagas disease. BENEFIT, a TDR-supported trial, is expected to fill this knowledge gap for the use of benznidazole.
24. Have there been any new treatments developed for Chagas disease since the 1960s?
No.
25. How are the drugs administered to the patients?
Benznidazole: Patients generally receive two or three daily doses for a period of 30 - 60 days.
Nifurtimox: Treatment regimen is for 60-90 days, and also divided in two or three daily doses.
There is no curative treatment for chronic symptomatic disease. In this phase, patients usually receive palliative drugs.
26. What are the current treatments available for children?
Neither benznidazole or nifurtimox is currently available in a pediatric formulation. DNDi is developing a paediatric tablet of benznidazole, in partnership with Laboratório Farmacêutico do Estado de Pernambuco (LAFEPE), a Brazilian public health institution.
Infants and children are currently treated by dividing a 100mg adult benznidazole tablet in up to 12 pieces, by crushing the pill fraction and diluting it in water, juice or milk. This practice risks making the treatment inefficient and unsafe due to variation and imprecision in drug dosing.
27. What are the limitations of the current treatments?
The limitations of current treatments are the long treatment period (30, 60, or 90 days), the toxicity of the drug, extreme side effects and the lack of a pediatric formulation. These limitations cause high rate of patient non-compliance.
28. What are the side effects of the current drugs available?
Benznidazole: The main side effects of benznidazole are skin inflammations, which occur between the seventh and tenth days of treatment, often associated with swollen or enlarged lymph nodes.15 Reduced motor and sensory function is dose dependent and usually occurs after the 6th week of treatment. Other observed side effects are nausea, headache, blood disorders , fever, muscle pain, and joint pain.
Nifurtimox: The most common side effects are digestive: abdominal pain, nausea and vomiting, loss of appetite, weight loss. Psychiatric disturbances, inflammation of the nervous system, and decreased white blood cell counts may also occur.
29. Is there a treatment for the chronic phase of the Chagas disease?
A number of experts now recommend treatment of adults in the indeterminate stages of T cruzi infection, who are in the absence of advanced Chagas cardiomyopathy. The BENEFIT trial (BENznidazole Evaluation For Interrupting Trypanosomiasis') is currently under way, and should help clarify treatment decisions for this group of patients.
30. Do the drugs available kill the parasite effectively?
Parasitological cure is thought to occur in 60% to 85% of patients in the acute phase and in more than 90% of congenitally infected infants treated in the first year of life. Efficacy is lower as the time of infection advances in chronic disease, and tools to evaluate parasitological cure at chronic phases are limited.
31. Do all infected people receive treatment?
No. The reported number of patients treated for Chagas disease remains extremely low. The lack of affordable medical tools for diagnosis and treatment that are adapted to the rural conditions where Chagas is most common greatly hinders effective patient care and management. In fact, the number of Chagas patients treated in non-endemic countries such as Spain, Switzerland and the US are comparable to, and sometimes greater than, the number of patients reported to be treated in disease-endemic countries like Mexico or Colombia, where the vast majority of infected patients live.
Benznidazole, the most common treatment for Chagas disease in Latin America, is most effective (and less toxic) in children and adolescents. There is no accepted treatment program for the millions of adults infected with chronic Chagas disease.
