Penbutolol


Concise Prescribing Info
Indications/Uses
HTN.
Dosage/Direction for Use
Adult : PO Initial: 20 mg/day, up to 40-80 mg/day if needed.
Dosage Details
Oral
Hypertension
Adult: Initially, 20 mg daily, increased to 40-80 mg/day if needed.
Administration
May be taken with or without food.
Contraindications
AV block (2nd and 3rd degree), sinus bradycardia, bronchial asthma, cardiogenic shock.
Special Precautions
Bronchospastic disease, compensated heart failure, DM, myasthenia gravis, untreated phaeochromocytoma, peripheral vascular disease including Raynaud's disease. May mask signs and symptoms of hyperthyroidism and acute hypoglycaemia. Avoid abrupt withdrawal as it may precipitate thyroid storm, exacerbate angina, HTN and MI. Patients undergoing surgery involving general anaesth. Pregnancy and lactation.
Adverse Reactions
Headache, dizziness, fatigue, insomnia, asthenia, arrhythmia, diaphoresis, CHF, nausea, diarrhoea, dyspepsia, upper resp tract infection, dyspnoea, cough, chest and limb pain, excessive sweating, impotence.
MonitoringParameters
Monitor BP and heart rate.
Overdosage
Symptoms: Bradycardia, hypotension, bronchospasm and acute cardiac failure. Management: Consider gastric emptying. IV atropine sulfate may be given to induce vagal blockade, and if bradycardia persists, administer IV isoproterenol HCl cautiously. For hypotension, sympathomimetic drugs (e.g. dobutamine, dopamine, levarterenol) may be given. IV glucagon may be useful in refractory cases. For bronchospasm, a β2-agonist and/or IV aminophylline may be considered.
Drug Interactions
Concomitant use w/ digitalis glycosides may increase the risk of bradycardia. Hypoglycaemic effects of insulin and antidiabetics may be prolonged. Coadministration w/ Ca antagonist may lead to synergistic hypotensive effects, bradycardia and arrhythmias. Additive effects w/ anaesth agents that depress the myocardium (e.g. cyclopropane, ether, trichloroethylene). Catecholamine-depleting drugs (e.g. reserpine) may enhance hypotensive effects. May enhance the rebound hypertensive effect of clonidine.
Action
Description: Penbutolol is a non-cardioselective β-blocker w/ some intrinsic sympathomimetic activity but lacks membrane-stabilising properties.
Onset: 1.5-3 hr.
Duration: >20 hr.
Pharmacokinetics:
Absorption: Readily absorbed from GI tract. Bioavailability: Approx 100%. Time to peak plasma concentration: Approx 1-3 hr.
Distribution: Plasma protein binding: 80-98%.
Metabolism: Undergoes extensive hepatic metabolism via hydroxylation and glucuronidation.
Excretion: Via urine (as metabolites). Elimination half-life: Approx 20 hr.
Storage
Store between 20-25°C. Protect from light.
MIMS Class
References
Anon. Penbutolol. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 28/11/2013.

Buckingham R (ed). Penbutolol Sulfate. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 28/11/2013.

Levatol (Actient Pharmaceuticals, LLC). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 28/11/2013.

Wickersham RM. Penbutolol Sulfate. Facts and Comparisons [online]. St. Louis, MO. Wolters Kluwer Clinical Drug Information, Inc. https://www.wolterskluwercdi.com/facts-comparisons-online/. Accessed 28/11/2013.

Disclaimer: This information is independently developed by MIMS based on Penbutolol from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 MIMS. All rights reserved. Powered by MIMS.com
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