Urapidil is a new antihypertensive vasodilator agent whose pharmacologic action in man has not yet been fully defined. We have assessed the alpha adrenergic blocking activity of urapidil 15 and 30 mg given intravenously in a single blind study in 8 healthy volunteers. Urapidil produced dose-dependent parallel shift of the phenylephrine log dose/blood pressure response curve, consistent with significant competitive peripheral alpha1 antagonism. Mean dose ratios were 2.99 and 5.48 for the 15 mg and 30 mg doses respectively. The pA2 for alpha1 blockade is 7.3. Given these data, the major mechanism of antihypertensive effect of urapidil may be alpha1 antagonism in the peripheral vaculature.
|Number of pages
|Research Communications in Chemical Pathology and Pharmacology
|Published - 1988
ASJC Scopus subject areas
- Pathology and Forensic Medicine
- Pharmacology, Toxicology and Pharmaceutics(all)