N"-Cyano-N-4-pyridyl-N'-1,2,2-trimethyl-propylguanidine, a new vasodilating agent: acute effect of blood pressure and pharmacokinetics in hypertensive patients.

N"-Cyano-N-4-pyridyl-N'-1,2,2-trimethylpropylguanidine (P 1134) is a new vasodilating antihypertensive compound. In an open study, P 1134 was given in single oral doses of from 10 to 25 mg to 12 previously untreated patients with essential hypertension. All patients responded with decreases in mean arterial pressure (MAP) of at least 10 mm Hg and with almost equal blood pressure decreases in the supine and erect position. The increase of dose was significantly correlated with a progressive reduction of blood pressure. At a dose of 25 mg, the maximal decrease in supine MAP averaged 38 mm Hg, and the maximal increase in heart rate averaged 23 beats/min. Peak effect and serum concentration were seen about 1 h after tablet intake. The serum half-life from the peak concentration averaged 2.5 h. It is concluded that P 1134 is a fast-acting, effective antihypertensive agent.