Trypanocidal drugs for late stage, symptomatic Chagas disease (Trypanosoma cruzi infection)

BACKGROUND: People with Chagas disease (American Trypanosomiasis) may develop progressive and potentially lethal heart conditions. Drugs to eliminate the causative parasite, Trypanosoma cruzi, currently in use have limited therapeutic value and are used in early stages of the disease. Extending the use of these drugs to treat symptomatic chronic parasitism with chronic Chagasic cardiopathy (CCC) and progressive dilated cardiomyopathy has been proposed. OBJECTIVES: To assess the effects (harms and benefits) of nitrofurans and imidazolic trypanocidal drugs for treating late stage chronic Chagas disease and CCC. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 1, 2008), MEDLINE (1985 to March 2008), EMBASE (1985 to March 2008), BIREME (1985-2004), LILACS (1985 to March 2008), ARTEMISA (1985-2004), SCIELO (1985-2004). Indexing terms in English and Spanish were used. References obtained were assessed for relevance by two reviewers independently. SELECTION CRITERIA: We included randomized controlled clinical trials (RCTs), single or double blind using trypanocidal drugs versus placebo or no treatment in CCC. DATA COLLECTION AND ANALYSIS: All articles retrieved were assessed using a predefined check list to determine if they met the inclusion criteria. Two independent reviewers collected data using a pre-designed form piloted on three articles before the review process started. Disagreements were resolved by a third reviewer. If the information was unavailable the articles were excluded. We planned a quantitative analysis of reduction of parasite load whether recorded as a categorical variable or the reduction of specific antibody titers. However insufficient data were available for quantitative analysis. We prepared a qualitative description of data identified. MAIN RESULTS: We found only one randomized double blind placebo controlled trial. We also found six uncontrolled or non-randomized studies which were of some relevance and were therefore described. We found insufficient evidence to define the effects of drug treatment for people with CCC. AUTHORS' CONCLUSIONS: There is insufficient evidence to support the efficacy of nitrofurans or imidazolic drugs as recommended treatment in CCC and chronic T.cruzi infections, specifically if overt heart disease is present. A well designed randomized controlled trial is necessary to establish if new drugs are suitable for treatment of cardiac patients with CCC.