N''-cyano-N-4-pyridyl-N'-1,2,2-trimethylpropylguanidine, monohydrate (P 1134): a new, potent vasodilator.

N''-cyano-N-4-pyridyl-N'-1,2,2-trimethylpropylguanidine, monohydrate (P 1134) is a new agent which induces a marked and sustained hypotensive response in normotensive and renal, neurogenic, and spontaneously hypertensive rats, as well as in normotensive and renal hypertensive dogs. The overall potency of this compound is 2-3 times greater than that of hydralazine. The fall of blood pressure is accompanied by an increase in heart rate and cardiac output and a decrease in total peripheral resistance. The hypotensive effect appears to be due primarily to a direct relaxant effect on vascular smooth muscle.