Cardiovascular effects of pinacidil and propranolol alone and in combination in normal humans.

The effects of a long-acting formulation of pinacidil (P1134), a new arteriolar vasodilator, have been investigated in normal humans. We observed the effects of pinacidil 37.5 mg when given alone, and when given in combination with propranolol 40 mg. The reflex tachycardia observed in the supine and standing positions after pinacidil was reduced by concurrent administration of propranolol. Combined treatment reduced systolic arterial pressure in the standing position from 117.0 +/- 2.5 to 98.3 +/- 3.5 mm Hg at 4 h after drug administration (p less than 0.01), which was greater than the hypotensive effect produced by either drug alone. These results indicate that the combination of pinacidil and a beta-adrenoceptor antagonist may be of value in the treatment of arterial hypertension.