Labetalol

Brand names: LabetalolNormodyne®Trandate®

Chemical formula:

Drug Forms:
• Labetalol Hydrochloride Oral tablet (below)
• Labetalol injection
• Labetalol Hydrochloride Solution for injection

Español:
• Clorhidrato de Labetalol, Tableta oral
• Inyección de labetalol
• Clorhidrato de labetalol, Solución para inyección

Labetalol Hydrochloride Oral tablet

What is this medicine?

LABETALOL (la BET a lole) is a beta-blocker. Beta-blockers reduce the workload on the heart and help it to beat more regularly. This medicine is used to treat high blood pressure.
 
This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:
•diabetes
•history of heart attack, heart disease or heart failure
•kidney disease
•liver disease
•lung or breathing disease, like asthma or emphysema
•pheochromocytoma
•thyroid disease
•an unusual or allergic reaction to labetalol, other beta-blockers, medicines, foods, dyes, or preservatives
•pregnant or trying to get pregnant
•breast-feeding

How should I use this medicine?

Take this medicine by mouth with a glass of water. Follow the directions on the prescription label. Take your doses at regular intervals. Do not take your medicine more often than directed. Do not stop taking this medicine suddenly. This could lead to serious heart-related effects.

Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.
NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

What may interact with this medicine?

Do not take this medicine with any of the following medications:
•sotalol

This medicine may also interact with the following medications:
•cimetidine
•diltiazem
•general anesthetics
•medicines for asthma or lung disease like albuterol
•medicines for high blood pressure
•medicines for depression
•nitroglycerin
•verapamil

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medicine?

Visit your doctor or health care professional for regular check ups. Check your blood pressure and pulse rate regularly. Ask your health care professional what your blood pressure and pulse rate should be, and when you should contact him or her.

You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine affects you. Do not stand or sit up quickly. Alcohol may interfere with the effect of this medicine. Avoid alcoholic drinks.

This medicine can affect blood sugar levels. If you have diabetes, check with your doctor or health care professional before you change your diet or the dose of your diabetic medicine.

Do not treat yourself for coughs, colds, or pain while you are taking this medicine without asking your doctor or health care professional for advice. Some ingredients may increase your blood pressure.

What side effects may I notice from receiving this medicine?

Side effects that you should report to your doctor or health care professional as soon as possible:
•allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
•breathing problems
•cold hands or feet
•dark urine
•depression
•general ill feeling or flu-like symptoms
•irregular heartbeat
•light-colored stools
•loss of appetite, nausea
•pain or trouble passing urine
•right upper belly pain
•slow heart rate (fewer than recommended by your doctor or health care professional)
•swollen legs or ankles
•tingling of the scalp or skin
•unusually weak or tired
•vomiting
•yellowing of the eyes or skin

Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):
•decreased sexual function or desire
•dry itching skin
•headache
•tiredness

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Where should I keep my medicine?

Keep out of the reach of children.

Store at room temperature between 15 and 30 degrees C (59 and 86 degrees F). Protect from light. Keep container tightly closed. Throw away any unused medicine after the expiration date.

Last updated: 7/1/2002

Important Disclaimer: The drug information provided here is for educational purposes only. It is intended to supplement, not substitute for, the diagnosis, treatment and advice of a medical professional. This drug information does not cover all possible uses, precautions, side effects and interactions. It should not be construed to indicate that this or any drug is safe for you. Consult your medical professional for guidance before using any prescription or over the counter drugs.

The noun has one meaning:

Meaning #1: antihypertensive drug (trade names Trandate and Normodyne) that blocks alpha and beta-adrenergic receptors of the sympathetic nervous system (leading to a decrease in blood pressure)
  Synonyms: labetalol hydrochloride, Trandate, Normodyne

Labetalol

Systematic (IUPAC) name
(RS)-2-hydroxy-5-{1-hydroxy-2-[(1-methyl-3-phenylpropyl)amino]ethyl}benzamide
Identifiers
CAS number	36894-69-6
ATC code	C07AG01
PubChem	3869
DrugBank	APRD01062
ChemSpider	3734
Chemical data
Formula	C19H24N2O3
Mol. mass	328.406 g/mol
SMILES	eMolecules & PubChem
Pharmacokinetic data
Bioavailability	90-100%
Protein binding	50%
Metabolism	hepatic pass metabolism,
Half life	Tablet: 6-8 hours; IV: 5.5 hours
Excretion	Excreted in urine, not removed by hemodialysis
Therapeutic considerations
Pregnancy cat.	C One of few drugs used for PIH
Legal status	℞ Prescription only
Routes	oral iv
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Labetalol (Normodyne, Trandate, fixed combination with hydrochlorothiazide: Normozyde) is a mixed alpha/beta Adrenergic antagonist, which is used to treat high blood pressure.^[1]

Contents 1 Chemistry 2 Indications 3 Administration 4 Side effects 5 Contraindications 6 References

Chemistry

Labetalol has stereoisomers.^[2] It is a racemic mixture of four isomers. 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, is a mixed nonselective β blocker and selective β₂ agonist.

It works by blocking these adrenergic receptors, which decreases peripheral vascular resistance without significantly altering heart rate or cardiac output. The β:α antagonism of Labetalol is approximately 3:1.^[3][4]

Indications

It has a particular indication in the treatment of pregnancy-induced hypertension which is commonly associated with pre-eclampsia. ^[5]

It is also used to treat chronic hypertension of pheochromocytoma and hypertensive crisis.^[3]

Administration

Labetalol is available in 100, 200, and 300 mg tablets and intravenously (only as Trandate) in 5 mg/ml solution. Adults taking tablets usually start with 100 mg twice daily, with a maximum of 2.4 g/day. In cases of emergency dosage might be higher. IV doses are usually started at 20mg over 2 minutes. Additional doses of 40mg, then 80mg may be administered every ten minutes as needed. Additional 80mg doses can be given to a total maximum dose of 300 mg. Additionally, labetalol can be administered by IV infusion at a rate of 2mg/minute, with a maximum dose of 300mg.

Side effects

Side effects may include:

• Drowsiness
• Fatigue
• Weakness
• Difficulty sleeping
• Diminished sexual function
• Scalp tingling which passes after time.
• 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, or those in cardiogenic shock.

References

1. ^ 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. PMID 18505576. PMC 2429901. http://www.pssjournal.com/content/2//13. 
2. ^ 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. PMID 1687367. 
3. ^ ^{a b} Katzung, Bertram G. (2006). Basic and clinical pharmacology. New York: McGraw-Hill Medical. p. 170. ISBN 0-07-145153-6. 
4. ^ 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. PMID PMC1428931. 
5. ^ http://www.bnf.org/bnf/bnf/56/2488.htm?q=%22labetalol%22

v • d • e Adrenergics Receptor Ligands α α1 Agonists: Amidephrine • Cirazoline • Dopamine • Epinephrine (Adrenaline) • Etilefrine • Isoprenaline • Levonordefrin • Metaraminol • Methoxamine • Methyldopa • Norepinephrine (Noradrenaline) • Oxymetazoline • Phenylephrine Antagonists: Alfuzosin • Arotinolol • Carvedilol • Doxazosin • Indoramin • L-765,314 • Labetalol • Moxisylyte • Nantenine • Phentolamine • Phenoxybenzamine • Prazosin • Silodosin • Tamsulosin • Terazosin • Tolazoline • Trimazosin • Urapidil α2 Agonists: (R)-3-Nitrobiphenyline • 4-NEMD • Amitraz • Apraclonidine • Brimonidine • Clonidine • Detomidine • Dexmedetomidine • Dopamine • Epinephrine (Adrenaline) • Etilefrine • Guanabenz • Guanfacine • Guanethidine • Guanoxabenz • Levonordefrin • Lofexidine • Medetomidine • Methyldopa • Norepinephrine (Noradrenaline) • Octopamine • Romifidine • Tizanidine • Tolonidine • Xylazine • Xylometazoline Antagonists: 1-PP • Atipamezole • BRL-44408 • Buspirone • Cirazoline • Efaroxan • Gepirone • Idazoxan • Ipsapirone • Mianserin • Mirtazapine • NAN-190 • Phentolamine • Phenoxybenzamine • Rauwolscine • SB-269,970 • Setiptiline • Spiroxatrine • Tandospirone • Tolazoline • Yohimbine α? Agonists: Anisodamine • Ephedrine • Ergotamine • Indanidine • Mephentermine • Midodrine • Mivazerol • Naphazoline • Phenylpropanolamine • Pseudoephedrine • Rilmenidine • Synephrine • Talipexole • Tetrahydrozoline β β1 Agonists: Denopamine • Dobutamine • Dopamine • Epinephrine (Adrenaline) • Etilefrine • Levonordefrin • Methyldopa • Norepinephrine (Noradrenaline) Antagonists: Acebutolol • Alprenolol • Amosulalol • Arotinolol • Atenolol • Bupranolol • Carvedilol • Celiprolol • Betaxolol • Bisoprolol • Dichloroisoprenaline • Esmolol • Labetalol • Metipranolol • Metoprolol • Nadolol • Nebivolol • Oxprenolol • Penbutolol • Pindolol • Practolol • Pronethalol • Propranolol • Sotalol • Tertatolol • Timolol • Tilisolol • Xamoterol β2 Agonists: Arformoterol • Bambuterol • Bitolterol • Carbuterol • Clenbuterol • Dopamine • Dopexamine • Epinephrine (Adrenaline) • Etilefrine • Fenoterol • Formoterol • Hexoprenaline • Indacaterol • Levonordefrin • Levosalbutamol • Methyldopa • Norepinephrine (Noradrenaline) • Orciprenaline • Pirbuterol • Procaterol • Reproterol • Rimiterol • Ritodrine • Salbutamol (Albuterol) • Salmeterol • Terbutaline • Tulobuterol Antagonists: Alprenolol • Amosulalol • Arotinolol • Bupranolol • Butaxamine • Carvedilol • Dichloroisoprenaline • ICI 118551 • Labetalol • Metipranolol • Nadolol • Oxprenolol • Penbutolol • Pindolol • Pronethalol • Propranolol • Sotalol • Tertatolol • Timolol • Tilisolol β3 Agonists: Amibegron • Arotinolol • Dopamine • Epinephrine (Adrenaline) • Etilefrine • Labetalol • Levonordefrin • Methyldopa • Norepinephrine (Noradrenaline) • Solabegron Antagonists: Carvedilol • SR 59230A β? Agonists: Arbutamine • BAAM • Befunolol • Broxaterol • Buphenine • Cimaterol • Ephedrine • Higenamine • Isoetarine • Isoxsuprine • Mabuterol • Methoxyphenamine • Oxyfedrine • Prenalterol • Pseudoephedrine • Ractopamine • Tretoquinol • Zilpaterol • Zinterol Reuptake Inhibitors Plasmalemmal NET Inhibitors Norepinephrine Reuptake Inhibitors: Atomoxetine (Tomoxetine) • Ciclazindol • Mazindol • Nisoxetine • Reboxetine • Tandamine • Tapentadol • Viloxazine; Norepinephrine-Dopamine Reuptake Inhibitors: Amineptine • Bupropion (Amfebutamone) • Fencamine • Fencamfamine • Lefetamine • LR-5182 • Manifaxine • Methylphenidate • Nomifensine • O-2172 • Radafaxine; Serotonin-Norepinephrine Reuptake Inhibitors: Bicifadine • Desvenlafaxine • Duloxetine • Milnacipran • Sibutramine • Tramadol • Venlafaxine; Serotonin-Norepinephrine-Dopamine Reuptake Inhibitors: Brasofensine • Diclofensine • DOV-102,677 • DOV-21,947 • DOV-216,303 • JNJ-7925476 • JZ-IV-10 • Methylnaphthidate • Naphyrone • NS-2359 • PRC200-SS • SEP-225,289 • SEP-227,162 • Tesofensine; Tricyclic Antidepressants: Amitriptyline • Butriptyline • Cianopramine • Clomipramine • Desipramine • Dosulepin • Doxepin • Imipramine • Lofepramine • Nortriptyline • Protriptyline • Trimipramine; Tetracyclic Antidepressants: Amoxapine • Maprotiline • Mianserin • Oxaprotiline; Others: Cocaine • Nefazodone • Nefopam • Ziprasidone TRPC6 Activators Adhyperforin • Hyperforin Vesicular VMAT Inhibitors Ibogaine • Reserpine • Tetrabenazine Releasing Agents Oxazolines: 4-Methylaminorex (4-MAR, 4-MAX) • Aminorex • Clominorex • Cyclazodone • Fenozolone • Fluminorex • Pemoline • Thozalinone; Phenethylamines (also Amphetamines, Cathinones, Phentermines, etc): 2-Hydroxyphenethylamine (2-OH-PEA) • 4-Methylamphetamine (4-MA) • 4-Methylmethamphetamine (4-MMA) • Alfetamine • Amphetamine (Dextroamphetamine, Levoamphetamine) • Amphetaminil • Amfepentorex • β-Methylphenethylamine (β-Me-PEA) • Benzodioxolylbutanamine (BDB) • Benzodioxolylhydroxybutanamine (BOH) • Benzphetamine • Buphedrone • Butylone • Cathine • Cathinone • Clobenzorex • Clortermine • Diethylcathinone (Diethylpropion, Amfepramone) • Dimethoxyamphetamine (DMA) • Dimethoxymethamphetamine (DMMA) • Dimethylamphetamine • Dimethylcathinone (Dimethylpropion, Metamfepramone) • Ephedrine (EPH) • Ethcathinone (Ethylpropion) • Ethylamphetamine • Ethylbenzodioxolylbutanamine (EBDB) • Ethylone • Fenethylline • Fenproporex • Flephedrone • Fludorex • Furfenorex • Hordenine • Indanorex • Indanylamphetamine (IAP) • Lisdexamfetamine • Lophophine (Homomyristicylamine) • Mefenorex • Mephedrone • Mephentermine • Methamphetamine (Desoxyephedrine, Methedrine; Dextromethamphetamine, Levomethamphetamine) • Methcathinone (Methylpropion) • Methedrone • Methoxymethylenedioxyamphetamine (MMDA) • Methoxymethylenedioxymethamphetamine (MMDMA) • Methylbenzodioxolylbutanamine (MBDB) • Methylenedioxyamphetamine (MDA; Tenamfetamine) • Methylenedioxyethylamphetamine (MDEA) • Methylenedioxyhydroxyamphetamine (MDOH) • Methylenedioxymethamphetamine (MDMA) • Methylenedioxymethylphenethylamine (MDMPEA; Homarylamine) • Methylenedioxyphenethylamine (MDPEA; Homopiperonylamine) • Methylone • Naphthylamphetamine (NAP) • Ortetamine • Oxaflozane • Parabromoamphetamine (PBA) • Parachloroamphetamine (PCA) • Parafluoroamphetamine (PFA) • Parafluoromethamphetamine (PFMA) • Parahydroxyamphetamine (PHA) • Paraiodoamphetamine (PIA) • Paramethoxyamphetamine (PMA) • Paramethoxyethylamphetamine (PMEA) • Paramethoxymethamphetamine (PMMA) • Paredrine (Norpholedrine, Oxamphetamine) • Phendimetrazine • Phenethylamine (PEA) • Phenmetrazine • Pholedrine • Phenpentermine • Phenpromethamine • Phentermine • Phenylpropanolamine (PPA) • Propylamphetamine • Pseudoephedrine (PSE) • Tiflorex (Flutiorex) • Tyramine (TRA) • Xylopropamine • Zylofuramine; Piperazines: 2,5-Dimethoxy-4-bromobenzylpiperazine (2C-B-BZP) • Benzylpiperazine (BZP) • Methoxyphenylpiperazine (MeOPP; Paraperazine) • Methylbenzylpiperazine (MBZP) • Methylenedioxybenzylpiperazine (MDBZP; Piperonylpiperazine) • Parafluorophenylpiperazine (pFPP; Fluoperazine); Others: 2-Aminoindane (2-AI) • 2-Aminotetralin (2-AT) • 2-Benzylpiperidine (2-BP) • 4-Benzylpiperidine (4-BP) • Clofenciclan • Cyclopentamine • Cypenamine • Cyprodenate • Feprosidnine • Gilutensin • Heptaminol • Hexacyclonate • Isometheptene • Methylhexanamine • Octodrine • Phthalimidopropiophenone • Propylhexedrine (PHX) • Tuaminoheptane (Tuamine) Enzyme Inhibitors Anabolism PAH Inhibitors 3,4-Dihydroxystyrene TH Inhibitors 3-Iodotyrosine • Aquayamycin • Bulbocapnine • Metirosine • Oudenone AAAD Inhibitors Benserazide • Carbidopa DBH Inhibitors Disulfiram • Nepicastat • Tropolone PNMT Inhibitors CGS-19281A • SKF-64139 • SKF-7698 Catabolism MAO Inhibitors Nonselective: Etryptamine • Furazolidone • Hydralazine • Iproclozide • Iproniazid • Isocarboxazid • Isoniazid • Linezolid • Mebanazine • Metryptamine • Nialamide • Phenelzine • Pheniprazine • Phenoxypropazine • Pivalylbenzhydrazine • Procarbazine • Safrazine • Tranylcypromine; MAO-A Selective: Befloxatone • Brofaromine • Cimoxatone • Clorgiline • Harmala Alkaloids (Harmine, Harmaline, Tetrahydroharmine, etc) • Minaprine • Moclobemide • Pirlindole • Toloxatone • Tyrima; MAO-B Selective: Lazabemide • Pargyline • Rasagiline • Selegiline * Note that MAO-B inhibitors also influence norepinephrine/epinephrine levels since they inhibit the breakdown of their precursor dopamine. COMT Inhibitors Entacapone • 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+) Others Activity Enhancers: Benzofuranylpropylaminopentane (BPAP) • Phenylpropylaminopentane (PPAP); Release Blockers: Bretylium • Guanethidine

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