Benznidazole and Chagas disease: can an old drug be the answer to an old problem?

BACKGROUND: Chagas disease is a significant public health problem in the Americas, despite efforts to decrease the number of new cases since 1990. Etiologic treatment of the disease's chronic phase is still controversial. OBJECTIVE: We reviewed the strongest studies to evaluate the drugs used in the acute and chronic disease phases, with emphasis on benznidazole. METHODS: A Medline search using the keywords 'Chagas disease' and 'treatment,' with no date limitations, was performed. RESULTS: Study methods in completed trials varied greatly, with none being a randomized, double-blind, placebo-controlled study. The only trial using these methods is still ongoing. The treatment in acute phase is the major indication, but during chronic phase doubts still remain. CONCLUSION: Only patients in the acute phase of Chagas disease (whatever their age; including children and adolescents) who are treated have good outcomes, although the criteria defining 'cure' remain controversial.

Coronary flow reserve in sickle cell anemia.

BACKGROUND: Patients with sickle cell anemia (SCA) frequently present with episodes of chest pain, alterations in the resting electrocardiogram, and changes in cardiac structure and functions. OBJECTIVE: To evaluate the effect of recurrent episodes of vaso-occlusion on the coronary microcirculation. METHODS: Coronary flow velocity and coronary flow reserve (CFR) of stable patients with SCA (n=10, 5 females, 24.4+/-5.4 years) were measured in the anterior descending coronary artery with transesophageal echocardiogram at baseline and after intravenous adenosine-induced maximum hyperemia, and compared to those of patients with sickle cell trait (TRA, n=10, 5 females, 27.7+/-3.2 years), iron deficiency anemia (IRO, n=8, 8 females, 26.6+/-5.2 years) and control group (NOR, n=10, 5 females, 26.3+/-6.3 years). RESULTS: The SCA group presented increased diastolic coronary flow velocities (p<0.01) at baseline and during maximum hyperemia (67.3+/-14.0 and 198.2+/-37.9 cm/s, respectively) when compared with the other three groups - TRA (34.4+/-11.9 and 114.7+/-36.4 cm/s), IRO (42.4+/-10.4 and 141.0+/-18.7 cm/s) and NOR (38.1+/-10.0 and 126.8+/-24.6 cm/s). However, CFR was normal in the SCA group (3.0+/-0.7) and comparable (p=0.70) to the other groups - TRA (3.4+/-0.8), IRO (3.5+/-1.2), and NOR (3.4+/-0.8). CONCLUSION: Despite the higher coronary flow velocities already observed at baseline and also during maximum hyperemia, CFR is normal in SCA, which suggests preserved coronary microcirculation. The episodes of vaso-occlusion are not responsible for the cardiologic findings in this disease.