Clinical pharmacologic investigations with carvedilol, a new beta-blocker with direct vasodilator activity.

Carvedilol (BM 14.190) has been shown to have beta-adrenergic blocking and vasodilating activity. By means of digital plethysmography, the threshold for vasodilation was ascertained at a dose of 2.6 mg iv infused over 1 hour. The oral threshold dose was established at about 15 mg, with a linear increase in response (r = 0.78) up to 76.5 mg. This dose increased blood flow to the forearm by reduction of arterial resistance. Although venous capacity was not changed, postural symptoms in three subjects could also be indicative of venous involvement. Carvedilol, 50 mg, reduced exercise heart rate for about 10 hours.