Cardiotoxicity of 5-flourouracil: two case reports.

Cardiotoxicity is a rare but serious side effect of 5-flourouracil (5-FU). The cardiotoxicity incidence of 5-FU is increasing with its frequent use in chemotherapy protocols. To explain the mechanism of this cardiotoxicity, many theories have been suggested by different authors. Most commonly, coronary artery vasospasm and flouroacetate,a toxic metabolite of 5-FU, are considered responsible for the toxicity. Ischemic symptoms and signs related to 5-FU are observed during the late phase of the administration of the drug. The close and careful monitorization of all the patients, especially the ones with pre-existent coronary artery disease, during 5-FU infusion is mandatory. Because there is not a single and effective modality of treatment or prophylaxis for 5-FU cardiotoxicity, the patients should be selected carefully for 5-FU administration and 5-FU infusion should be stopped as soon as a symptom is encountered.