Comparison of hemodynamic effects of furosemide and piretanide in normovolemic patients

The effects of furosemide and piretanide (Hoe 118) on the pulmonary hemodynamics in 20 patients recovering from uncomplicated myocardial infarctions were compared in a double-blind study. The diuretic effects and half-lives of the two drugs were not significantly different, so that their hemodynamic actions could be compared directly. Both drugs progressively reduced cardiac output and pressures in the pulmonary circulation, whereas systemic vascular resistance increased significantly. Both drugs slightly increased pulmonary blood volume but not significantly. Total blood volume decreased less rapidly than cardiac output, so that the ratio of cardiac output to total blood volume decreased with time. We conclude that both drugs increase venous compliance in normovolemic subjects and probably increase the compliance of pulmonary vessels.