Abstract
1 Labetalol at a dose of 800 to 1600 mg daily inhibited isoprenaline-induced tachycardia and phenylephrine-induced elevation in arterial pressure in hypertensive subjects. The β-adrenoreceptor effect was four times more potent than the α-adrenoreceptor effect.
2 Isoprenaline-induced tachycardia was more effectively blocked than isoprenaline-induced inotropism, thereby raising the possibility of a subselective effect on cardiac β-adrenoceptors.
3 Labetalol reduced blood pressure in hypertensive subjects with no change in cardiac output in the supine or upright position and with marked inhibition of the heart rate and blood pressure response to treadmill exercise.
4 Labetalol administered in single doses to patients with stable, treated congestive heart failure impaired blood pressure support during exercise.
5 The unique adrenoceptor and haemodynamic effects of labetalol make it a potentially attractive drug for management of hypertension and other cardiovascular disorders.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Akhtar N., Mikulic E., Cohn J. N., Chaudhry M. H. Hemodynamic effect of dobutamine in patients with severe heart failure. Am J Cardiol. 1975 Aug;36(2):202–205. doi: 10.1016/0002-9149(75)90526-3. [DOI] [PubMed] [Google Scholar]
- Bonelli J. Demonstration of two different types of beta1-receptors in man (selective blockade of the positively inotropic and the positively chronotropic effect of isoproterenol). Int J Clin Pharmacol Biopharm. 1978 Jul;16(7):313–319. [PubMed] [Google Scholar]
- Cohn J. N., Franciosa J. A. Vasodilator therapy of cardiac failure: (first of two parts). N Engl J Med. 1977 Jul 7;297(1):27–31. doi: 10.1056/NEJM197707072970105. [DOI] [PubMed] [Google Scholar]
- Epstein S., Robinson B. F., Kahler R. L., Braunwald E. Effects of beta-adrenergic blockade on the cardiac response to maximal and submaximal exercise in man. J Clin Invest. 1965 Nov;44(11):1745–1753. doi: 10.1172/JCI105282. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Graham R. M., Thornell I. R., Gain J. M., Bagnoli C., Oates H. F., Stokes G. S. Prazosin: the first-dose phenomenon. Br Med J. 1976 Nov 27;2(6047):1293–1294. doi: 10.1136/bmj.2.6047.1293. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Johnson J. A., Davis J. O., Gotshall R. W., Lohmeier T. E., Davis J. L., Braverman B., Tempel G. E. Evidence for an intrarenal beta receptor in control of renin release. Am J Physiol. 1976 Feb;230(2):410–418. doi: 10.1152/ajplegacy.1976.230.2.410. [DOI] [PubMed] [Google Scholar]
- Khatri I. M., Cohn J. N. Mechanism of exercise hypotension after sympathetic blockade. Am J Cardiol. 1970 Mar;25(3):329–338. doi: 10.1016/s0002-9149(70)80011-x. [DOI] [PubMed] [Google Scholar]
- McDonald R. H., Jr, Corder C. N., Leenen F. H. Alpha and beta blockers: effects on renin release. Prog Brain Res. 1977;47:409–416. doi: 10.1016/S0079-6123(08)62744-2. [DOI] [PubMed] [Google Scholar]
- Mehta J., Cohn J. N. Hemodynamic effects of labetalol, an alpha and beta adrenergic blocking agent, in hypertensive subjects. Circulation. 1977 Feb;55(2):370–375. doi: 10.1161/01.cir.55.2.370. [DOI] [PubMed] [Google Scholar]
- Richards D. A., Woodings E. P., Prichard B. N. Circulatory and alpha-adrenoceptor blocking effects of phentolamine. Br J Clin Pharmacol. 1978 Jun;5(6):507–513. doi: 10.1111/j.1365-2125.1978.tb01665.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Simon G., Kiowski W., Julius S. Effect of systemic autonomic inhibition on the hemodynamic response to antihypertensive therapy with timolol. Int J Clin Pharmacol Biopharm. 1979 Dec;17(12):507–510. [PubMed] [Google Scholar]
- Sowton E., Hamer J. Hemodynamic changes after beta adrenergic blockade. Am J Cardiol. 1966 Sep;18(3):317–320. doi: 10.1016/0002-9149(66)90048-8. [DOI] [PubMed] [Google Scholar]
- Swedberg K., Hjalmarson A., Waagstein F., Wallentin I. Beneficial effects of long-term beta-blockade in congestive cardiomyopathy. Br Heart J. 1980 Aug;44(2):117–133. doi: 10.1136/hrt.44.2.117. [DOI] [PMC free article] [PubMed] [Google Scholar]