Acute and Long-Term Hemodynamic Effects of Carvedilol, a Combined β-Adrenoceptor Blocking and Precapillary Vasodilating Agent, in Hypertensive Patients

The purpose of these studies was to investigate the hemodynamic effects of carvedilol, a compound with combined properties of nonselective beta-adrenoceptor blockade and precapillary vasodilatation. The acute effects were studied with invasive technique (dye dilution) in 10 patients taking 25 mg orally and noninvasively (forearm plethysmography) in 10 patients taking 25 mg and in 10 patients taking 50 mg orally, all with essential hypertension. Significant reductions of systolic and diastolic blood pressure (p less than 0.05-0.001) were observed in all groups. Total peripheral resistance (TPR) did not change acutely whereas resistance in the forearm was reduced by 16% (p less than 0.05; invasive group). When a comparison with propranolol (80 mg x 2) was made in a randomized double-blind placebo controlled trial in 30 patients, carvedilol acutely reduced blood pressure significantly by 13/6 mg Hg (25 mg) and 17/10 mm Hg (50 mg) in contrast to propranolol. Resistance in the forearm fell significantly with 50 mg carvedilol, whereas propranolol caused a significant rise. After 4 weeks, both compounds had reduced blood pressure significantly. Blood flow was still reduced with propranolol in contrast to the findings with carvedilol. In conclusion, the summary of these studies shows that carvedilol given orally has a useful antihypertensive effect both acutely and during prolonged treatment, and it has an attractive hemodynamic profile, in agreement with the hemodynamic findings in essential hypertension.