Pharmacology of Combined α-β-Blockade I

  title={Pharmacology of Combined $\alpha$-$\beta$-Blockade I},
  author={William John Louis and John J. McNeil and Olaf H. Drummer},
SumarySeveral compounds of the chemical class arylethanolamines have been shown to possess combined α- or vasodilator and β-adrenoceptor blocking properties. The first drug was labetalol (AH5158)[5-(1-hydroxy-2)1-methyl-3-phenylpropyl(amino)-ethyl(salicylamide)]. Others include medroxalol, bucindolol and YM-09538, which differ from labetalol either by the nature of the substitution on the primary benzene ring and/or on the terminal nitrogen. All of these drugs are non-selective β-blockers… 
14 Citations

Combined α- and β-Receptor Inhibition in the Treatment of Hypertension

The combination of α- with β-adrenoceptor blockade represents a useful addition to the drugs available for the treatment of hypertension, and labetalol is used in all grades of hypertension alone or in combination with other antihypertensives when required.

Progress in Antihypertensive Therapy with a Multiple-Action Drug

The mode of antihypertensive action of β-blockade remains unclear, as does the exact contribution of the 3 mechanisms of peripheral vasodilatation, but the combination of pharmacological effects represents an additional means of lowering blood pressure.

Antihypertensive treatment with beta-blockers in the metabolic syndrome: a review.

Vasodilating action of Carvedilol and Nebivolol, due respectively to alpha1-blocking effect and release of nitric oxide, explains the lack of adverse metabolic effects of these beta-blockers that could also be used in hypertensive patients with metabolic syndrome.

Pharmacological management of hypertensive emergencies and urgencies: focus on newer agents

Clevidipine, a third-generation dihydropyridine calcium-channel blocker with unique pharmacodynamic and pharmacokinetic properties was added to the therapeutic armamentarium and was shown in clinical trials to reduce mortality when compared with nitroprusside.

Heart rate control with adrenergic blockade: Clinical outcomes in cardiovascular medicine

Clinical evidence suggests that attainment of HR control is an important treatment objective for patients with cardiovascular conditions, and vasodilating β-blocker efficacy may aid in accomplishing improved outcomes.

Impact of intravenous infusion of labetalol combined with magnesium sulfate versus hydralazine combined with magnesium sulfate on fetomaternal hemodynamics in severe preeclampsia

Both labetalol and hydralazine intravenous infusion regimens are well tolerated and effective in controlling severe hypertension in pregnant women with severe preeclampsia in combination with magnesium sulfate.

Treatment of Acute Severe Hypertension

Patients with hypertensive emergencies are best treated in an intensive care unit with titratable, intravenous, hypotensive agents, including labetalol, esmolol, fenoldopam, nicardipine and sodium nitroprusside.



New developments in alpha-adrenoreceptor drugs for the treatment of hypertension.

It is suggested that differences between alpha-adrenoreceptors in various tissues may allow development of highly selective alpha 2- adrenoreceptor agonists for specific tissue sites such as the juxtaglomerular cells and brainstem nuclei controlling blood pressure.

Pharmacology of AH 5158; a drug which blocks both α‐ and β‐adrenoceptors

The results show AH 5158 to possess a novel profile of activity and resembles propranolol in decreasing rather than increasing total peripheral resistance and in causing larger decreases in arterial blood pressure at equipotent β‐adrenoceptor blocking doses.

β and α‐Adrenoceptor Antagonism by Medroxalol in Healthy Volunteers: Relationship to Dose and Plasma Concentration

It is concluded that medroxalol has a long plasma elimination half-life, exerts a marked and prolonged β-adrenoceptor blockade, and has significant but less marked α-adRenoceptor blocking properties, which appear only after oral administration of the drug.


Labetalol appears to act as a postsynaptic α‐adrenoceptor antagonist in the isolated blood perfused spleen of the cat with little effect on presynaptic α-adrenOceptors.

β‐Adrenergic–receptor blockers and antinuclear antibodies in hypertension

Although some of the beta blockers may be associated with an increase in ANA incidence, the dramatic effects of acebutolol do not appear to be a group property.

Inhibition of oxidative drug metabolism by beta-adrenoceptor antagonists in related to their lipid solubility.

The use of a beta blocker and a benzodiazepine (diazepam) in the treatment of anxiety and its major metabolite and preliminary observations on their disposition kinetics in man are reviewed.

Pharmacological effects of labetalol in man.

It was concluded that in man labetalol possesses combined alpha- and beta-adrenoreceptor antagonist properties.

Cardiovascular Properties of Medroxalol, A New Antihypertensive Drug

It was concluded that the principal action of medroxalol was to produce a fall in blood pressure by decreasing peripheral vascular resistance more than cardiac output.


  • G. M. Drew
  • Biology, Chemistry
    British journal of pharmacology
  • 1978
The results demonstrate that the presynaptic α‐adrenoceptors in the guinea‐pig ileum are of the same type as those located presynaptically in sympathetically innervated tissues.