Fluvastatin, an agent of a class of lipid-lowering drugs, the "statins", significantly enhanced prostacyclin synthesis at the concentrations of 0.1 microM and 1 microM and significantly reduced endothelin production at the concentrations 0.01, 0.1 and 1 microM in cell cultures of human umbilical endothelial veins. Since prostacyclin is a vasodilator and endothelin a vasoconstrictor, fluvastatin may have a significant effect on hemodynamics by favoring the balance towards vasodilation. This mechanism may contribute to the prevention of cardiovascular diseases.