II. Indications

  1. Refractory Hypertension
    1. Effective outpatient agent in oral form patients with Refractory Hypertension
  2. Hypertensive Emergency
    1. Nicardipine has replaced intravenous Labetalol for Hypertensive Emergency
      1. Labetalol is difficult to achieve Blood Pressure control in Hypertensive Crisis despite titration
      2. Labetalol is short acting
    2. Labetalol is a preferred agent when compared with Hydaralazine and Clonidine

III. Contraindications

IV. Pharmacokinetics

  1. Well absorbed and high first-pass metabolism (liver metabolism)

V. Mechanism

  1. Combination of classes (similar to Carvedilol)
    1. Lowers Blood Pressure without reflex Tachycardia
    2. Nonselective Beta Blocker (7 fold more beta than alpha activity)
      1. Binds vascular (and Bronchial) smooth muscle beta receptors
      2. Decreases Heart Rate, Cardiac Output and Blood Pressure
    3. Selective Alpha-1 Adrenergic Antagonist (weak compared with beta activity)
      1. Competitively binds vascular smooth muscle alpha-1 Adrenergic Receptors
      2. Blocks peripheral blood vessel Vasoconstriction
  2. Primary activity is as a negative inotrope
    1. Chronotropic effect is mild

VI. Dosing: Adults

  1. Adjust dose in liver and renal Impairment
  2. Oral
    1. Start: 100 mg orally twice daily
    2. Target: 200 to 600 mg orally twice daily
    3. Maximum: 2400 mg/day
  3. Intravenous Injection
    1. Start: 20 mg slow IV injection
    2. Next: 40-80 mg every 10 minutes as needed
    3. Cummulative Maximum: 200-300 mg
  4. Intravenous Infusion
    1. Start 0.5 to 2 mg/min IV up to cummulative maximum of 200-300 mg

VII. Dosing: Children (Not FDA approved)

  1. Oral
    1. Start: 4 mg/kg/day orally divided twice daily
    2. Maximum: 40 mg/kg/day up to adult maximum of 2400 mg
  2. Intravenous Infusion
    1. Dose: 0.3 to 1 mg/kg/dose up to 20 mg slow IV injection up to every 10 minutes
    2. Cummulative Maximum: 200-300 mg
  3. Intravenous Infusion
    1. Start 0.4 to 1 mg/kg/hour IV up to 3 mg/kg/hour

VIII. Adverse Effects

IX. Drug Interactions

  1. Systemic Beta Agonists
    1. Labetalol blocks bronchodilation

X. References

  1. Olson (2020) Clinical Pharmacology, MedMaster, Miami, p. 66
  2. Hamilton (2020) Tarascon Pocket Pharmacopeia, Jones and Bartlett, accessed on IOS, 4/9/2021

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Related Studies

Cost: Medications

labetalol (on 5/17/2017 at Medicaid.Gov Survey of pharmacy drug pricing)
LABETALOL HCL 100 MG TABLET Generic $0.22 each
LABETALOL HCL 200 MG TABLET Generic $0.26 each
LABETALOL HCL 300 MG TABLET Generic $0.47 each

Ontology: Labetalol (C0022860)

Definition (MSH) A salicylamide derivative that is a non-cardioselective blocker of BETA-ADRENERGIC RECEPTORS and ALPHA-1 ADRENERGIC RECEPTORS.
Definition (NCI) A third generation selective alpha-1-adrenergic antagonist and non-selective beta-adrenergic antagonist with vasodilatory and antihypertensive properties. Labetalol competitively binds to alpha-1-adrenergic receptors in vascular smooth muscle, thereby inhibiting the adrenergic stimulation of endothelial cell function and vasoconstriction in peripheral blood vessels. This agent also binds to beta-receptors in the bronchial and vascular smooth muscle, resulting in a decrease in adrenergic stimulation. The result is a decrease in resting and exercise heart rates, cardiac output, and in both systolic and diastolic blood pressure, thereby resulting in vasodilation, and negative chronotropic and inotropic cardiac effects.
Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH D007741
SnomedCT 372750000, 46547007
LNC LP16170-0, MTHU007202
English Labetalol, Labetolol, Benzamide, 2-hydroxy-5-(1-hydroxy-2-((1-methyl-3-phenylpropyl)amino)ethyl)-, Labetalol [Chemical/Ingredient], labetolol, LABETALOL, beta blockers labetalol, labetalol (medication), labetalol, Labetalol (product), Labetalol (substance)
Swedish Labetalol
Czech labetalol
Finnish Labetaloli
French Labétolol, Labétalol
Russian LABETALOL, AN 5158, АН 5158, ЛАБЕТАЛОЛ
Japanese ラベタロール
Italian Labetololo, Labetalolo
Croatian LABETALOL
Polish Labetalol
Spanish ibidomida, labetalol (producto), labetalol (sustancia), labetalol, Labetalol
German Labetalol
Portuguese Labetalol