Hemodynamic differences between carvedilol and labetalol in the cutaneous circulation.

The effects of labetalol and carvedilol on local cutaneous microvascular perfusion and calculated local cutaneous microvascular resistance were investigated in anesthetized rats at submaximal doses that produced equivalent reductions in blood pressure and heart rate. Labetalol decreased cutaneous perfusion (-25% +/- 3%) without significantly affecting cutaneous vascular resistance (-6% +/- 3%). In marked contrast, carvedilol dramatically increased cutaneous perfusion (+64% +/- 9%) and significantly reduced cutaneous vascular resistance (-57% +/- 3%). These results suggest that carvedilol and labetalol possess differences in the mechanisms by which they produce vasodilation in vivo.