Labetalol
Betablocking Agent · Beta-blocker
Indications
Angina co-existing with hypertension. Hypertension of pregnancy, hypertension following MI, hypertensive emergencies.
Dosage
Hypertension: ORAL: Adults: Initially 100 mg twice daily with food increasing if necessary at 14 day intervals; max 2.4 gm daily in three or four divided doses. Elderly: Initially 50 mg twice daily. INJECTION: Adults: IV: 20 mg (0.25 mg/kg for 80 kg patient) by IV injection over 2 min; may be administered 40-80 mg at 10 min intervals; up to 300 mg total dose. IV Infusion: Initial 2 mg/min; titrate to response up to 300 mg total dose, if needed. Hypertension of pregnancy: INFUSION: Adults: IV: Initially 20 mg/hr, then increased if required to 40 mg/hr after 30 min, then increased if required to 80 mg/hr after 30 min, then increased if required to 160 mg/hr after 30 min, altered as per response. Max: Usually 160 mg/hr. ORAL: Adults: Usual dose for hypertension. Hypertensive emergencies: INJECTION: Adults: IV: 50 mg, to be administered over at least 1 min, then 50 mg every 5 min if…
Administration
Administer slowly over 2 min by direct IV or by continuous IV infusion, at an initial rate of 2 mg/min with subsequent adjustments based on BP response. Standard diluent: 500 mg/250 mL D5W. Keep patient in supine position for 3 hours after IV administration. Compatibility: Stable in D5LR, D5NS, D5W, LR, NS. Y-site administration: Drug to Drug IV Compatibility: Amikacin, amiodarone, aztreonam, bumetanide, calcium gluconate, cimetidine, diltiazem, diphenhydramine, dobutamine, dopamine, enalapril, epinephrine, esmolol, famotidine, fentanyl, fluconazole, gentamicin, hydromorphone, imipenem, levofloxacin, linezolid, lorazepam, magnesium sulphate, methylprednisolone, metoclopramide, metronidazole, midazolam, milrinone, nitroglycerin, nitroprusside, norepinephrine, ondansetron, phenylephrine, propofol, ranitidine, tobramycin, vancomycin, vasopressin, vecuronium. Drug to Drug IV…
Adverse Effects
Cardiovascular effects including bradycardia, postural hypotension. Rarely, heart failure, increased AV block, cardiac arrhythmias. Raynaud's phenomenon cold extremities, sexual dysfunction. GI, sleep and CNS disturbances. Dyspnoea rarely, bronchospasm. Skin reactions, withdraw if unexplained dry eyes or rash. Fatigue, paraesthesia, peripheral neuropathy, arthralgia, myopathy, altered blood sugar, haematology and lipid levels.
Risk Factor (Pregnancy/Lactation)
Pregnancy: Risk cannot be ruled out. Lactation: Caution advised or effect undetermined. Contraindications: 2nd or 3rd degree AV block (without pacemaker), severe bradycardia, sick sinus syndrome, uncontrolled heart failure, cardiogenic shock, severe peripheral arterial disease, hypotension, metabolic acidosis, untreated pheochromocytoma, severe asthma or COPD, patients at risk of hypoglycaemia, Prinzmetal's angina, history of bronchospasm. Precautions: 1st degree AV block. Heart failure (avoid if uncontrolled). Peripheral arterial circulatory disorders (avoid if severe), Myasthaenia gravis. Ischaemic heart disease, withdraw gradually. History of bronchospasm. Diabetes, hyperthyroidism, renal or hepatic impairment, psoriasis. Elderly. Consider withdrawal before elective surgery. Anaphylaxis risk due to increased sensitivity to allergens. Always withdraw gradually over period of 1-2 weeks.
Interactions
Ca++ antagonists. Antihypertensives including centrally acting agents (e.g. clonidine), antiarrhythmics, antipsychotics. TCADs, MAOIs, fluvoxamine, barbiturates, cardiac glycosides, sympathomimetics, cimetidine, hydralazine, rifampicin, NSAIDs, ergot derivatives, erythromycin, anaesthetics, diuretics, digoxin, xanthines, insulin/oral hypoglycaemics, antimalarials, moxisylyte, iodinated contrast media, baclofen, levothyroxine, alcohol, corticosteroids, rizatriptan, muscle relaxants, contraceptives, parasympathomimetics, fingolimod, ampicillin.
Advice to Patient
Take with meals. Contact prescriber if there is fatigue; depression; numbness; confusion; rash; tingling of fingers, toes or skin; palpitations; slowed heartbeat; difficulty in respiration; edema or cold extremities. Avoid alcohol during therapy. Do not stop medication abruptly. If you have diabetes, regularly check blood glucose level. Change position slowly.
Pharmacokinetics
Onset of action: Oral: 20 min-2 hrs. IV: Within 5 min. Peak effect: Oral: 2-4 hrs. IV: 5-15 min. Duration: BP response: Oral: 8-12 hrs. IV: Average: 16-18 hrs. Absorption: Complete. Metabolism: Hepatic; extensive first-pass effect. Bioavailability: Oral: 25%. Half-life elimination: Oral: 6-8 hrs. IV: Approx. 5.5 hrs. Time to peak, plasma: Oral: 1-2 hrs. Excretion: Primarily urine. Faeces.
Brands with this active ingredient
Compiled by Healify Pharmacy from published drug references. How we compile it →
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