Labetalol
|
Systematic (IUPAC) name |
(RS)-2-hydroxy-5-{1-hydroxy-2-[(1-methyl-3-phenylpropyl)amino]ethyl}benzamide
|
Clinical data |
Trade names |
Normodyne, Trandate |
AHFS/Drugs.com |
monograph |
MedlinePlus |
a685034 |
Pregnancy
category |
- C
One of few drugs used for PIH
|
Legal status |
|
Routes of
administration |
oral iv |
Pharmacokinetic data |
Bioavailability |
25% |
Protein binding |
50% |
Metabolism |
hepatic pass metabolism, |
Biological half-life |
Tablet: 6-8 hours; IV: 5.5 hours |
Excretion |
Excreted in urine, not removed by hemodialysis |
Identifiers |
CAS Registry Number |
36894-69-6 Y |
ATC code |
C07AG01 |
PubChem |
CID: 3869 |
IUPHAR/BPS |
7207 |
DrugBank |
DB00598 Y |
ChemSpider |
3734 Y |
UNII |
R5H8897N95 Y |
KEGG |
D08106 Y |
ChEBI |
CHEBI:6343 Y |
ChEMBL |
CHEMBL429 Y |
Chemical data |
Formula |
C19H24N2O3 |
Molecular mass |
328.406 g/mol |
SMILES
-
O=C(c1cc(ccc1O)C(O)CNC(C)CCc2ccccc2)N
|
InChI
-
InChI=1S/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) Y
-
Key:SGUAFYQXFOLMHL-UHFFFAOYSA-N Y
|
Y (what is this?) (verify) |
Labetalol (INN) () (trade names Normodyne and Trandate) is a mixed alpha/beta adrenergic antagonist that is used to treat high blood pressure.[1]
Contents
- 1 Medical uses
- 2 Side effects
- 3 Contraindications
- 4 Chemistry
- 5 Mechanism of action
- 6 See also
- 7 References
Medical uses
It has a particular indication in the treatment of pregnancy-induced hypertension which is commonly associated with pre-eclampsia.[2]
It is also used to treat chronic and acute hypertension of pheochromocytoma and hypertensive crisis.[3]
Side effects
Side effects may include:
- Drowsiness
- Fatigue
- Weakness
- Difficulty sleeping
- Diminished sexual function
- Orthostatic hypotension (due to alpha receptor blockade)
- Scalp tingling
- Hyperkalemia
- Hepatotoxicity
- Drug eruption similar to lichen planus[4]
- A rare but potentially lethal side effect is respiratory distress.
Contraindications
Labetalol has relative contraindications for use in patients with asthma, congestive heart failure, any degree of heart block, bradycardia, hypotension or those in cardiogenic shock.
Chemistry
For adrenergic agents, when the substituent on the amine nitrogen is greater in size than a t-butyl group, then the molecule typically is found to have receptor affinity without intrinsic activity, and is therefore an antagonist.[5] Labetalol has two chiral carbons and consequently exists as four stereoisomers.[6] Two of these isomers, the (S,S)- and (R,S)- forms are inactive. The third, the (S,R)-isomer, is a powerful α1 blocker. The fourth isomer, the (R,R)-isomer which is also known as dilevalol, is a mixed nonselective β blocker and selective α1 blocker.
Labetalol acts by blocking alpha and beta adrenergic receptors, resulting in decreased peripheral vascular resistance without significant alteration of heart rate or cardiac output. The β:α antagonism of labetalol is approximately 3:1.[3][7]
Mechanism of action
Labetalol 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.
Labetalol has local anesthetic activity.[8]
Labetalol, in animal models, was found to cross the blood-brain-barrier in only negligible amounts.[9]
See also
References
- ^ Fahed S, Grum DF, Papadimos TJ (2008). "Labetalol infusion for refractory hypertension causing severe hypotension and bradycardia: an issue of patient safety". Patient Saf Surg 2: 13. doi:10.1186/1754-9493-2-13. PMC 2429901. PMID 18505576.
- ^ http://www.bnf.org/bnf/bnf/56/2488.htm?q=%22labetalol%22
- ^ a b Katzung, Bertram G. (2006). Basic and clinical pharmacology. New York: McGraw-Hill Medical. p. 170. ISBN 0-07-145153-6.
- ^ Shiohara T, Kano Y (2007). "Lichen planus and lichenoid dermatoses". In Bolognia JL. Dermatology. St. Louis: Mosby. p. 161. ISBN 1-4160-2999-0.
- ^ Medicinal Chemistry of Adrenergics and Cholinergics
- ^ Riva E, Mennini T, Latini R (December 1991). "The alpha- and beta-adrenoceptor blocking activities of labetalol and its RR-SR (50:50) stereoisomers". Br. J. Pharmacol. 104 (4): 823–8. doi:10.1111/j.1476-5381.1991.tb12513.x. PMC 1908821. PMID 1687367.
- ^ D A Richards, J Tuckman, and B N Prichard (October 1976). "Assessment of alpha- and beta-adrenoceptor blocking actions of labetalol". Br J Clin Pharmacol 3 (5): 849–855. doi:10.1111/j.1365-2125.1976.tb00637.x. PMC 1428931. PMID 9968.
- ^ Exam Zone (1 January 2009). Elsevier Comprehensive Guide. Elsevier India. pp. 449–. ISBN 978-81-312-1620-0.
- ^ Detlev Ganten; Patrick J. Mulrow (6 December 2012). Pharmacology of Antihypertensive Therapeutics. Springer Science & Business Media. pp. 147–. ISBN 978-3-642-74209-5.
Beta blockers (C07)
|
|
β, non-selective |
- Alprenolol
- Bopindolol
- Bupranolol
- Carteolol
- Cloranolol
- Mepindolol
- Nadolol
- Oxprenolol
- Penbutolol
- Pindolol
- Propranolol
- Sotalol
- Tertatolol
- Timolol
|
|
β1-selective |
- Acebutolol
- Atenolol
- Betaxolol
- Bevantolol
- Bisoprolol
- Celiprolol
- Epanolol
- Esmolol
- Metoprolol
- Nebivolol
- Practolol
- S-Atenolol
- Talinolol
|
|
β2-selective |
|
|
α1- + β-selective |
|
|
-
- #WHO-EM
- ‡Withdrawn from market
- Clinical trials:
- †Phase III
- §Never to phase III
|
|
Index of the circulatory system
|
|
Description |
- Anatomy
- Arteries
- head and neck
- arms
- chest
- abdomen
- legs
- Veins
- head and neck
- arms
- chest
- abdomen and pelvis
- legs
- Development
- Cells
- Physiology
|
|
Disease |
- Congenital
- Neoplasms and cancer
- Lymphatic vessels
- Injury
- Vasculitis
- Other
- Symptoms and signs
|
|
Treatment |
- Procedures
- Drugs
- beta blockers
- channel blockers
- diuretics
- nonsympatholytic vasodilatory antihypertensives
- peripheral vasodilators
- renin–angiotensin system
- sympatholytic antihypertensives
- vasoprotectives
|
|
|
Adrenergics
|
|
Receptor ligands
|
|
α1 |
- Agonists
- 6-FNE
- Amidephrine
- Anisodamine
- Anisodine
- Buspirone
- Cirazoline
- Corbadrine
- Dipivefrine
- Dopamine
- Ephedrine
- Epinephrine
- Etilefrine
- Ethylnorepinephrine
- Indanidine
- Metaraminol
- Methoxamine
- Methyldopa
- Midodrine
- Naphazoline
- Norepinephrine
- Octopamine
- Oxymetazoline
- Phenylephrine
- Phenylpropanolamine
- Pseudoephedrine
- Synephrine
- Tetrahydrozoline
|
|
- Antagonists
- Abanoquil
- Adimolol
- Ajmalicine
- Alfuzosin
- Amosulalol
- Arotinolol
- Atiprosin
- Atypical antipsychotics (e.g., clozapine, olanzapine, quetiapine, risperidone)
- Benoxathian
- Buflomedil
- Bunazosin
- Carvedilol
- Corynanthine
- Dapiprazole
- Domesticine
- Doxazosin
- Ergolines (e.g., ergotamine, dihydroergotamine, lisuride, terguride)
- Etoperidone
- Eugenodilol
- Fenspiride
- Hydroxyzine
- Indoramin
- Ketanserin
- L-765,314
- Labetalol
- mCPP
- Mepiprazole
- Metazosin
- Monatepil
- Moxisylyte
- Naftopidil
- Nantenine
- Nefazodone
- Neldazosin
- Niaprazine
- Nicergoline
- Niguldipine
- Pardoprunox
- Pelanserin
- Phendioxan
- Phenoxybenzamine
- Phentolamine
- Piperoxan
- Prazosin
- Quinazosin
- Ritanserin
- Silodosin
- Spiperone
- Talipexole
- Tamsulosin
- Terazosin
- Tiodazosin
- Tolazoline
- Trazodone
- Tetracyclic antidepressants (e.g., amoxapine, maprotiline, mianserin)
- Tricyclic antidepressants (e.g., amitriptyline, clomipramine, doxepin, imipramine, trimipramine)
- Trimazosin
- Typical antipsychotics (e.g., chlorpromazine, fluphenazine, loxapine, thioridazine)
- Urapidil
- WB-4101
- Zolertine
|
|
|
α2 |
- Agonists
- (R)-3-Nitrobiphenyline
- 4-NEMD
- 6-FNE
- Amitraz
- Apraclonidine
- Brimonidine
- Cannabivarin
- Clonidine
- Corbadrine
- Detomidine
- Dexmedetomidine
- Dihydroergotamine
- Dipivefrine
- Dopamine
- Ephedrine
- Ergotamine
- Epinephrine
- Etilefrine
- Ethylnorepinephrine
- Guanabenz
- Guanfacine
- Guanoxabenz
- Lofexidine
- Medetomidine
- Methamphetamine
- Methyldopa
- Mivazerol
- Naphazoline
- Norepinephrine
- Oxymetazoline
- Phenylpropanolamine
- Piperoxan
- Pseudoephedrine
- Rilmenidine
- Romifidine
- Talipexole
- Tetrahydrozoline
- Tizanidine
- Tolonidine
- Urapidil
- Xylazine
- Xylometazoline
|
|
- Antagonists
- 1-PP
- Adimolol
- Aptazapine
- Atipamezole
- Atypical antipsychotics (e.g., asenapine, clozapine, lurasidone, paliperidone, quetiapine, risperidone, zotepine)
- Azapirones (e.g., buspirone, tandospirone)
- BRL-44408
- Buflomedil
- Cirazoline
- Efaroxan
- Esmirtazapine
- Fenmetozole
- Fluparoxan
- Idazoxan
- mCPP
- Mianserin
- Mirtazapine
- NAN-190
- Olanzapine
- Pardoprunox
- Phentolamine
- Phenoxybenzamine
- Piperoxan
- Piribedil
- Rauwolscine
- Rotigotine
- SB-269970
- Setiptiline
- Spiroxatrine
- Sunepitron
- Tolazoline
- Typical antipsychotics (e.g., chlorpromazine, fluphenazine, loxapine, thioridazine)
- Yohimbine
|
|
|
β |
- Agonists
- Amibegron
- Arbutamine
- Arformoterol
- Arotinolol
- BAAM
- Bambuterol
- Befunolol
- Bitolterol
- Broxaterol
- Buphenine
- Carbuterol
- Cimaterol
- Clenbuterol
- Corbadrine
- Denopamine
- Dipivefrine
- Dobutamine
- Dopamine
- Dopexamine
- Ephedrine
- Epinephrine
- Etafedrine
- Etilefrine
- Ethylnorepinephrine
- Fenoterol
- Formoterol
- Hexoprenaline
- Higenamine
- Indacaterol
- Isoetarine
- Isoprenaline
- Isoxsuprine
- Levosalbutamol
- Mabuterol
- Methoxyphenamine
- Methyldopa
- Mirabegron
- Norepinephrine
- Orciprenaline
- Oxyfedrine
- Phenylpropanolamine
- Pirbuterol
- Prenalterol
- Ractopamine
- Procaterol
- Pseudoephedrine
- Reproterol
- Rimiterol
- Ritodrine
- Salbutamol
- Salmeterol
- Solabegron
- Terbutaline
- Tretoquinol
- Tulobuterol
- Vilanterol
- Xamoterol
- Zilpaterol
- Zinterol
|
|
- Antagonists
- Acebutolol
- Adaprolol
- Adimolol
- Afurolol
- Alprenolol
- Alprenoxime
- Amosulalol
- Ancarolol
- Arnolol
- Arotinolol
- Atenolol
- Befunolol
- Betaxolol
- Bevantolol
- Bisoprolol
- Bopindolol
- Bornaprolol
- Brefonalol
- Bucindolol
- Bucumolol
- Bufetolol
- Bufuralol
- Bunitrolol
- Bunolol
- Bupranolol
- Butaxamine
- Butidrine
- Butofilolol
- Capsinolol
- Carazolol
- Carpindolol
- Carteolol
- Carvedilol
- Celiprolol
- Cetamolol
- Cicloprolol
- Cinamolol
- Cloranolol
- Cyanopindolol
- Dalbraminol
- Dexpropranolol
- Diacetolol
- Dichloroisoprenaline
- Dihydroalprenolol
- Dilevalol
- Diprafenone
- Draquinolol
- Ecastolol
- Epanolol
- Ericolol
- Ersentilide
- Esatenolol
- Esprolol
- Eugenodilol
- Exaprolol
- Falintolol
- Flestolol
- Flusoxolol
- Hydroxycarteolol
- Hydroxytertatolol
- ICI-118,551
- Idropranolol
- Indenolol
- Indopanolol
- Iodocyanopindolol
- Iprocrolol
- Isoxaprolol
- Isamoltane
- Labetalol
- Landiolol
- Levobetaxolol
- Levobunolol
- Levomoprolol
- Medroxalol
- Mepindolol
- Metipranolol
- Metoprolol
- Moprolol
- Nadolol
- Nadoxolol
- Nebivolol
- Nifenalol
- Nipradilol
- Oxprenolol
- Pacrinolol
- Pafenolol
- Pamatolol
- Pargolol
- Penbutolol
- Pindolol
- Practolol
- Primidolol
- Procinolol
- Pronethalol
- Propafenone
- Propranolol
- Ridazolol
- Ronactolol
- Soquinolol
- Sotalol
- Spirendolol
- SR 59230A
- Sulfinalol
- Talinolol
- Tazolol
- Tertatolol
- Tienoxolol
- Tilisolol
- Timolol
- Tiprenolol
- Tolamolol
- Toliprolol
- Xibenolol
- Xipranolol
|
|
|
|
|
Reuptake inhibitors
|
|
NET |
- Selective norepinephrine reuptake inhibitors
- Amedalin
- Atomoxetine (tomoxetine)
- Ciclazindol
- Daledalin
- Edivoxetine
- Esreboxetine
- Lortalamine
- Mazindol
- Nisoxetine
- Reboxetine
- Talopram
- Talsupram
- Tandamine
- Viloxazine
|
|
- Norepinephrine-dopamine reuptake inhibitors
- Amineptine
- Bupropion
- Fencamine
- Fencamfamine
- Hydroxybupropion
- Lefetamine
- Levophacetoperane
- LR-5182
- Manifaxine
- Methylphenidate
- Nomifensine
- O-2172
- Radafaxine
|
|
- Serotonin-norepinephrine reuptake inhibitors
- Bicifadine
- Desvenlafaxine
- Duloxetine
- Eclanamine
- Levomilnacipran
- Milnacipran
- N-Methyl-PPPA
- PPPA
- Sibutramine
- Venlafaxine
|
|
- Serotonin-norepinephrine-dopamine reuptake inhibitors
- Brasofensine
- Dasotraline
- Desmethylsertraline
- Diclofensine
- DOV-102,677
- DOV-21,947
- DOV-216,303
- HDMP-28
- JNJ-7925476
- JZ-IV-10
- Liafensine
- Naphyrone
- NS-2359
- Perafensine
- PRC200
- Tesofensine
|
|
- Tricyclic antidepressants
- Amitriptyline
- Butriptyline
- Cianopramine
- Clomipramine
- Desipramine
- Dosulepin
- Doxepin
- Imipramine
- Lofepramine
- Melitracen
- Nortriptyline
- Protriptyline
- Trimipramine
|
|
- Tetracyclic antidepressants
- Amoxapine
- Maprotiline
- Mianserin
- Oxaprotiline
- Setiptiline
|
|
- Others
- Antihistamines (e.g., brompheniramine, chlorphenamine, pheniramine, tripelennamine)
- Arylcyclohexylamines (e.g., ketamine, phencyclidine)
- CP-39,332
- Ethanol
- EXP-561
- Fezolamine
- Ginkgo biloba
- Indeloxazine
- Loxapine
- Nefazodone
- Nefopam
- Opioids (e.g., methadone, pethidine (meperidine), tapentadol, tramadol)
- Pridefine
- Tedatioxetine
- Teniloxazine
- Tofenacin
- Tropanes (e.g., cocaine)
- Ziprasidone
|
|
|
VMATs |
- Amiodarone
- Amphetamines (e.g., amphetamine, methamphetamine, MDMA)
- Bietaserpine
- Deserpidine
- Efavirenz
- GBR-12935
- Ibogaine
- Ketanserin
- Lobeline
- Reserpine
- Rose bengal
- Tetrabenazine
- Vanoxerine (GBR-12909)
|
|
|
|
Releasing agents
|
|
- Morpholines
- Fenbutrazate
- Fenmetramide
- Morazone
- Morforex
- Phendimetrazine
- Phenmetrazine
- Pseudophenmetrazine
|
|
- Oxazolines
- 4-MAR
- Aminorex
- Clominorex
- Cyclazodone
- Fenozolone
- Fluminorex
- Pemoline
- Thozalinone
|
|
- Phenethylamines (also amphetamines, cathinones, etc)
- 2-OH-PEA
- 4-CAB
- 4-FA
- 4-FMA
- 4-MA
- 4-MMA
- Alfetamine
- Amfecloral
- Amfepentorex
- Amfepramone
- Amphetamine
- Dextroamphetamine
- Levoamphetamine
- Amphetaminil
- β-Me-PEA
- BDB
- Benzphetamine
- BOH
- Buphedrone
- Bupropion
- Butylone
- Cathine
- Cathinone
- Clobenzorex
- Clortermine
- Dimethylamphetamine
- DMA
- DMMA
- EBDB
- Ephedrine
- Ethcathinone
- Ethylone
- Etilamfetamine
- Famprofazone
- Fenethylline
- Fenproporex
- Flephedrone
- Fludorex
- Furfenorex
- Hordenine
- 4-Hydroxyamphetamine
- 5-APDI (IAP)
- 5-MAPDI (IMP)
- Iofetamine (123I)
- Lisdexamfetamine
- Lophophine
- MBDB
- MDA
- MDEA
- MDMA
- Metamfepramone
- MDMPEA
- MDOH
- MDPEA
- Mefenorex
- Mephedrone
- Mephentermine
- Methamphetamine
- Dextromethamphetamine
- Levomethamphetamine
- Methcathinone
- Methedrone
- Methylone
- Morforex
- Naphthylaminopropane
- Ortetamine
- pBA
- pCA
- Pentorex
- Phenethylamine
- Pholedrine
- Phenpromethamine
- Phentermine
- Phenylpropanolamine
- pIA
- Prenylamine
- Propylamphetamine
- Pseudoephedrine
- Selegiline (also D-Deprenyl)
- Tiflorex
- Tyramine
- Xylopropamine
- Zylofuramine
|
|
- Piperazines
- 2C-B-BZP
- BZP
- MBZP
- mCPP
- MDBZP
- MeOPP
- pFPP
|
|
- Others
- 2-ADN
- 2-AI
- 2-AT
- 2-BP
- 4-BP
- 5-IAI
- Clofenciclan
- Cyclopentamine
- Cypenamine
- Cyprodenate
- Feprosidnine
- Gilutensin
- Heptaminol
- Hexacyclonate
- Indanorex
- Isometheptene
- Methylhexanamine
- Octodrine
- Phthalimidopropiophenone
- Propylhexedrine (Levopropylhexedrine)
- Tuaminoheptane
|
|
|
|
Enzyme inhibitors
|
|
PAH |
|
|
TH |
- 3-Iodotyrosine
- Aquayamycin
- Bulbocapnine
- Metirosine
- Oudenone
|
|
AAAD |
- Benserazide
- Carbidopa
- DFMD
- Genistein
- Methyldopa
|
|
DBH |
- Bupicomide
- Disulfiram
- Dopastin
- Fusaric acid
- Nepicastat
- Phenopicolinic acid
- Tropolone
|
|
PNMT |
- CGS-19281A
- SKF-64139
- SKF-7698
|
|
MAO |
- Nonselective
- Benmoxin
- Caroxazone
- Echinopsidine
- Furazolidone
- Hydralazine
- Indantadol
- Iproclozide
- Iproniazid
- Isocarboxazid
- Isoniazid
- Linezolid
- Mebanazine
- Metfendrazine
- Nialamide
- Octamoxin
- Paraxazone
- Phenelzine
- Pheniprazine
- Phenoxypropazine
- Pivhydrazine
- Procarbazine
- Safrazine
- Tranylcypromine
|
|
- MAO-A selective
- Amiflamine
- Bazinaprine
- Befloxatone
- Brofaromine
- Cimoxatone
- Clorgiline
- CX157 (Tyrima)
- Eprobemide
- Esuprone
- Harmala alkaloids
- Harmine
- Harmaline
- Tetrahydroharmine
- Harman
- Methylene blue
- Metralindole
- Minaprine
- Moclobemide
- Pirlindole
- Sercloremine
- Tetrindole
- Toloxatone
|
|
- MAO-B selective
- Ladostigil
- Lazabemide
- Milacemide
- Mofegiline
- Pargyline
- Rasagiline
- Safinamide
- Selegiline (also D-Deprenyl)
|
|
|
COMT |
- Entacapone
- Nitecapone
- Tolcapone
|
|
|
|
Others
|
|
Precursors |
- L-Phenylalanine → L-Tyrosine → L-DOPA (Levodopa) → Dopamine
- L-DOPS (Droxidopa)
|
|
Cofactors |
- Ferrous Iron (Fe2+)
- S-Adenosyl-L-Methionine
- Vitamin B3 (Niacin
- Nicotinamide → NADPH)
- Vitamin B6 (Pyridoxine
- Pyridoxamine
- Pyridoxal → Pyridoxal Phosphate)
- Vitamin B9 (Folic acid → Tetrahydrofolic acid)
- Vitamin C (Ascorbic acid)
- Zinc (Zn2+)
|
|
Neurotoxins |
- DSP-4
- Oxidopamine (6-OHDA)
|
|
Others |
- Activity enhancers
- BPAP
- PPAP
|
|
- Release blockers
- Bethanidine
- Bretylium
- Guanadrel
- Guanazodine
- Guanethidine
- Guanoxan
|
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|
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- See also:
- Dopaminergics
- Melatonergics
- Serotonergics
- List of adrenergic drugs
|
|