Methods:

Healthy volunteers (n = 17) were examined at baseline and for 15 min after 60 s of hand cooling in ice-water. Finger temperature and digital plethysmography were recorded each minute from the cooled and the control hands. Measurements were also made before and 2 h after drug administration.

Results:

Blood pressure declined from 120/86 to 108/74 mm Hg after atenolol (n = 9), and from 122/88 to 108/73 mm Hg after carvedilol (n = 8). In both groups, baseline finger temperature increased slightly after drug, and a more rapid rise in finger temperature was observed after cooling. There was no group difference in the drug effect on finger temperature, except in the first few minutes after cooling, when temperature recovery was greater after carvedilol. Carvedilol reduced the vasoconstrictor response to local cooling (digital plethysmography), compared both to the value before drug and after atenolol. At rest, carvedilol changed the pulse curves (control hand) towards vasodilatation and high compliance, expressed as a mean change in the relative height of the dicrotic notch of −10.3% versus 0.0% after atenolol.

Conclusion:

Future studies should clarify whether the vasoactive profile of carvedilol may translate into reduced occurrence of cold hands and feet amongst patients treated for hypertension.