Changes of blood viscosity in pateints treated with 5-fluorouracil: A link to cardiotoxicity?

Abstract Cardiotoxicity is a serious but relatively unknown side-effect of treatment with 5-fluorouracil (5-FU). The underlying mechanism of 5-FU cardiotoxicity has not been defined. The aim of the present study was to determine whether hemorheological factors might in part explain 5-FU cardiotoxicity. Changes of blood and plasma viscosity, fibrinogen and hematocrit were studied in 11 patients treated by 5-FU. The study showed a decrease in blood and plasma viscosity during treatment with 5-FU, probably caused by a decrease of plasma fibrinogen. Reversible cardiotoxic effects were demonstrated in four patients.