RESUMEN
Itraconazole (ITZ) is widely prescribed for the treatment of mycosis such as Paracoccidioidomycosis (PCM). However, it's related to toxicity and serious adverse events, such as Congestive Heart Failure (CHF). The objective is to describe a patient with PCM and CHF secondary to ITZ. Male, 50-years old, was diagnosed with chronic adult PCM and started ITZ 200 mg 12/12 h. After 2-months, acute CHF began without previous-heart disease. The electrocardiogram showed changes in ventricular repolarization and left anterior superior divisional block. Echocardiogram: slight reduction in left ventricular systolic function and ejection fraction of 51%. ITZ was replaced by trimethoprim-sulfamethoxazole. After a week, there was remission of symptoms. Despite thousands of patients around the world received ITZ, few cases of CHF were reported. It's dose dependent and improves when the drug is discontinuing. ITZ has negative inotropic effect and probably causes mitochondrial dysfunction. However, the intrinsic mechanisms are not yet completely understood.