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Labetalol: a review of its pharmacology, pharmacokinetics, clinical uses and adverse effects.
Pharmacotherapy. 1983 Jul-Aug; 3(4):193-219.P

Abstract

Labetalol is a combined alpha- and beta-adrenoceptor blocking agent for oral and intravenous use in the treatment of hypertension. It is a nonselective antagonist at beta-adrenoceptors and a competitive antagonist of postsynaptic alpha 1-adrenoceptors. Labetalol is more potent at beta that at alpha 1 adrenoceptors in man; the ratio of beta-alpha antagonism is 3:1 after oral and 6.9:1 after intravenous administration. Labetalol is readily absorbed in man after oral administration, but the drug, which is lipid soluble, undergoes considerable hepatic first-pass metabolism and has an absolute bioavailability of approximately 25%. There are no active metabolites, and the elimination half-life of the drug is approximately 6 hours. Unlike conventional beta-adrenoceptor blocking drugs without intrinsic sympathomimetic activity, labetalol, when given acutely, produces a decrease in peripheral vascular resistance and blood pressure with little alteration in heart rate or cardiac output. However, like conventional beta-blockers, labetalol may influence the renin-angiotensin-aldosterone system and respiratory function. Clinical studies have shown that the antihypertensive efficacy of labetalol is superior to placebo and to diuretic therapy and is at least comparable to that of conventional beta-blockers, methyldopa, clonidine and various adrenergic neuronal blockers. Labetalol administered alone or with a diuretic is often effective when other antihypertensive regimens have failed. Studies have shown that labetalol is effective in the treatment of essential hypertension, renal hypertension, pheochromocytoma, pregnancy hypertension and hypertensive emergencies. In addition, preliminary studies indicate that labetalol may be of value in the management of ischemic heart disease. The most troublesome side effect of labetalol therapy is posture-related dizziness. Other reported side effects of the drug include gastrointestinal disturbances, tiredness, headache, scalp tingling, skin rashes, urinary retention and impotence. Side effects related to the beta-adrenoceptor blocking effect of labetalol, including asthma, heart failure and Raynaud's phenomenon, have been reported in rare instances.

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Authors

MacCarthy EP
No affiliation info available
Bloomfield SS
No affiliation info available

MeSH

AnimalsAnti-Arrhythmia AgentsCoronary DiseaseEthanolaminesHemodynamicsHumansHypertensionKidneyKineticsLabetalolNorepinephrineReceptors, Adrenergic, alphaReceptors, Adrenergic, betaRenin-Angiotensin SystemRespiratory SystemVasodilator Agents

Pub Type(s)

Journal Article
Review

Language

eng

PubMed ID

6310529

Citation

MacCarthy, E P., and S S. Bloomfield. "Labetalol: a Review of Its Pharmacology, Pharmacokinetics, Clinical Uses and Adverse Effects." Pharmacotherapy, vol. 3, no. 4, 1983, pp. 193-219.
MacCarthy EP, Bloomfield SS. Labetalol: a review of its pharmacology, pharmacokinetics, clinical uses and adverse effects. Pharmacotherapy. 1983;3(4):193-219.
MacCarthy, E. P., & Bloomfield, S. S. (1983). Labetalol: a review of its pharmacology, pharmacokinetics, clinical uses and adverse effects. Pharmacotherapy, 3(4), 193-219.
MacCarthy EP, Bloomfield SS. Labetalol: a Review of Its Pharmacology, Pharmacokinetics, Clinical Uses and Adverse Effects. Pharmacotherapy. 1983 Jul-Aug;3(4):193-219. PubMed PMID: 6310529.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Labetalol: a review of its pharmacology, pharmacokinetics, clinical uses and adverse effects. AU - MacCarthy,E P, AU - Bloomfield,S S, PY - 1983/7/1/pubmed PY - 1983/7/1/medline PY - 1983/7/1/entrez SP - 193 EP - 219 JF - Pharmacotherapy JO - Pharmacotherapy VL - 3 IS - 4 N2 - Labetalol is a combined alpha- and beta-adrenoceptor blocking agent for oral and intravenous use in the treatment of hypertension. It is a nonselective antagonist at beta-adrenoceptors and a competitive antagonist of postsynaptic alpha 1-adrenoceptors. Labetalol is more potent at beta that at alpha 1 adrenoceptors in man; the ratio of beta-alpha antagonism is 3:1 after oral and 6.9:1 after intravenous administration. Labetalol is readily absorbed in man after oral administration, but the drug, which is lipid soluble, undergoes considerable hepatic first-pass metabolism and has an absolute bioavailability of approximately 25%. There are no active metabolites, and the elimination half-life of the drug is approximately 6 hours. Unlike conventional beta-adrenoceptor blocking drugs without intrinsic sympathomimetic activity, labetalol, when given acutely, produces a decrease in peripheral vascular resistance and blood pressure with little alteration in heart rate or cardiac output. However, like conventional beta-blockers, labetalol may influence the renin-angiotensin-aldosterone system and respiratory function. Clinical studies have shown that the antihypertensive efficacy of labetalol is superior to placebo and to diuretic therapy and is at least comparable to that of conventional beta-blockers, methyldopa, clonidine and various adrenergic neuronal blockers. Labetalol administered alone or with a diuretic is often effective when other antihypertensive regimens have failed. Studies have shown that labetalol is effective in the treatment of essential hypertension, renal hypertension, pheochromocytoma, pregnancy hypertension and hypertensive emergencies. In addition, preliminary studies indicate that labetalol may be of value in the management of ischemic heart disease. The most troublesome side effect of labetalol therapy is posture-related dizziness. Other reported side effects of the drug include gastrointestinal disturbances, tiredness, headache, scalp tingling, skin rashes, urinary retention and impotence. Side effects related to the beta-adrenoceptor blocking effect of labetalol, including asthma, heart failure and Raynaud's phenomenon, have been reported in rare instances. SN - 0277-0008 UR - https://www.unboundmedicine.com/medline/citation/6310529/Labetalol:_a_review_of_its_pharmacology_pharmacokinetics_clinical_uses_and_adverse_effects_ L2 - https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0277-0008&date=1983&volume=3&issue=4&spage=193 DB - PRIME DP - Unbound Medicine ER -