Source:http://linkedlifedata.com/resource/umls/id/C0030812
MSH: A nonselective beta-blocker used as an antihypertensive and an antianginal agent.,NCI: A lipophilic, nonselective beta-adrenergic receptor antagonist with anti-anginal and antihypertensive activities. Penbutolol competitively binds to and blocks beta-1 adrenergic receptors in the heart, thereby decreasing cardiac contractility and rate. This leads to a reduction in cardiac output and lowers blood pressure. In addition, penbutolol prevents the release of renin, a hormone secreted by the kidneys that causes constriction of blood vessels.