3559
T3D3517
Labetalol
Labetalol is only found in individuals that have used or taken this drug. It is a blocker of both alpha- and beta-adrenergic receptors that is used as an antihypertensive (PubChem). Labetalol HCl combines both selective, competitive, alpha-1-adrenergic blocking and nonselective, competitive, beta-adrenergic blocking activity in a single substance. In man, the ratios of alpha- to beta- blockade have been estimated to be approximately 1:3 and 1:7 following oral and intravenous (IV) administration, respectively. The principal physiologic action of labetalol is to competitively block adrenergic stimulation of β-receptors within the myocardium (β1-receptors) and within bronchial and vascular smooth muscle (β2-receptors), and α1-receptors within vascular smooth muscle. This causes a decrease in systemic arterial blood pressure and systemic vascular resistance without a substantial reduction in resting heart rate, cardiac output, or stroke volume, apparently because of its combined α- and β-adrenergic blocking activity.
36894-69-6
3869
C19H24N2O3
328.178690
White powder.
188°C
117 mg/L (at 25°C)
Oral, parenteral (intravenous injection). Completely absorbed (100%) from the gastrointestinal tract with peak plasma levels occurring 1 to 2 hours after oral administration. The absolute bioavailability of labetalol is increased when administered with food.
Labetalol has two asymmetric centers and therefore, exists as a molecular complex of two diastereoisomeric pairs. Dilevalol, the R,R' stereoisomer, makes up 25% of racemic labetalol. Labetalol HCl combines both selective, competitive, alpha-1-adrenergic blocking and nonselective, competitive, beta-adrenergic blocking activity in a single substance. In man, the ratios of alpha- to beta- blockade have been estimated to be approximately 1:3 and 1:7 following oral and intravenous (IV) administration, respectively. Beta-2-agonist activity has been demonstrated in animals with minimal beta-1-agonist (ISA) activity detected. In animals, at doses greater than those required for alpha- or beta- adrenergic blockade, a membrane stabilizing effect has been demonstrated.
Primarily hepatic, undergoes significant first pass metabolism
Route of Elimination: These metabolites are present in plasma and are excreted in the urine, and via the bile, into the feces.
Half Life: 6-8 hours
LD50 = 66 mg/kg (Rat, parental-intravenous)
No indication of carcinogenicity to humans (not listed by IARC).
For the management of hypertension (alone or in combination with other classes of antihypertensive agents), as well as chronic stable angina pectoris and sympathetic overactivity syndrome associated with severe tetanus. Labetalol is used parenterally for immediate reduction in blood pressure in severe hypertension or in hypertensive crises when considered an emergency, for the control of blood pressure in patients with pheochromocytoma and pregnant women with preeclampsia, and to produce controlled hypotension during anesthesia to reduce bleeding resulting from surgical procedures.
Side effects or adverse reactions include dizziness when standing up, very low blood pressure, severely slow heartbeat, weakness, diminished sexual function, fatigue
2009-07-30T17:58:59Z
2014-12-24T20:26:07Z
Labetalol
C07063
6343
Labetalol
DB00598
true
CC(CCC1=CC=CC=C1)NCC(O)C1=CC(C(O)=N)=C(O)C=C1
C19H24N2O3
InChI=1/C19H24N2O3/c1-13(7-8-14-5-3-2-4-6-14)21-12-18(23)15-9-10-17(22)16(11-15)19(20)24/h2-6,9-11,13,18,21-23H,7-8,12H2,1H3,(H2,20,24)
InChIKey=SGUAFYQXFOLMHL-UHFFFAOYNA-N
328.4055
328.178692644
Exogenous
Solid
3.09
HMDB14736
CHEMBL429
3734
<p>U.S. Patent 4,012,444.</p>