Several drugs are now known to have useful activity against Trypanosoma cruzi, the causative agent of human
American trypanosomiasis (
Chagas disease). However, the long-term effects of
chemotherapy on the electrocardiographic (ECG) abnormalities associated with this disease have only been assessed for benznidiazole. In the present study, the ECG changes in 299 cases of chronic
Chagas disease were followed for 9 years
after treatment with
itraconazole (N = 136) or
allopurinol (N = 163). Among the 97 cases who were found to have ECG abnormalities immediately prior to their treatment, the two drugs appeared equally effective, such abnormalities being corrected in 23 (50%) of the 46 cardiopathy cases given
itraconazole and 25 (49%) of the 51 given
allopurinol (P > 0.05). Both of these 'cure rates' are much higher than the 8.1% frequency of abnormal-normal conversion observed among 198 'historical controls' (i.e. cases of chronic
Chagas disease who had been left untreated; P < 0.05).
Itraconazole appeared better than
allopurinol at preventing the development of cardiopathy in the cases who appeared electrocardiographically normal at baseline. Among 202 such cases, only two (2.2%) of the 90 treated with
itraconazole but 28 (25.0%) of the 112 given
allopurinol were found to have developed ECG abnormalities during follow-up (P < 0.05). Therefore, although
itraconazole and
allopurinol are equally effective at reversing ECG alterations,
itraconazole offers better protection against the development of new ECG abnormalities among those with chronic
Chagas disease.