Metoprolol


Concise Prescribing Info
Indications/Uses
Listed in Dosage.
Dosage/Direction for Use
Adult : PO Hypertension Conventional tab: Initially, 100 mg daily as single or in 2 divided doses, may be increased weekly according to response. Maintenance: 200 mg daily in divided doses. Extended release tab: Initially, 25-100 mg daily, may be increased weekly according to response. Max: 400 mg/day. Angina pectoris Conventional tab: 50-100 mg bid or tid. Extended-release: Initially, 100 mg daily, may be increased gradually at weekly intervals until satisfactory response is achieved. Max: 400 mg/day. Heart failure Extended-release tab: 12.5-25 mg once daily, may be increased gradually as tolerated, at intervals of 2 weeks. Max dose: 200 mg once daily. Cardiac arrhythmias Conventional tab: 50 mg bid or tid, may be increased to 300 mg daily in divided doses, as necessary. Adjunct in hyperthyroidism Conventional tab: 50 mg qid, may be reduced once euthyroid state is achieved. Prophylaxis of migraine Conventional tab: 100-200 mg daily in divided doses. IV Adjunct in the early management of acute myocardial infarction Within 12 hours of onset of chest pain: 5 mg at a 2 minute intervals to total of 15 mg, if tolerated. Patients who have received full IV dose: After 15 minutes, initiate oral therapy of 50 mg every 6 hours for 2 days. Patients who did not tolerate the full IV dose: Reduced oral dose should be given as and when their condition permits. Subsequent oral maintenance: 100 mg bid. Patients not given an IV inj: 200 mg in 2 or 4 divided doses started when patient's condition stabilises. Cardiac arrhythmias Initially, 5 mg injected at a rate of 1-2 mg/minute, may be repeated if necessary at a 5-minute interval to a total dose of 10-15 mg. Prophylaxis or control of arrhythmias on induction of anaesthesia 2-4 mg as slow injection, may further give 2 mg injections as necessary. Max dose: 10 mg.
Dosage Details
Intravenous
Adjunct in the early management of acute myocardial infarction
Adult: Within 12 hours of onset of chest pain: 5 mg at a 2 minute intervals to a total of 15 mg, if tolerated. Patients who have received full IV dose: After 15 minutes, initiate oral therapy of 50 mg every 6 hours for 2 days. Patients who did not tolerate the full IV dose: Reduced oral dose should be given as and when their condition permits. Subsequent oral maintenance: 100 mg bid. Patients not given an IV inj: 200 mg in 2 or 4 divided doses started when patient's condition stabilises.
Elderly: Reduce dose as necessary.

Intravenous
Prophylaxis or control of arrhythmias on induction of anaesthesia
Adult: 2-4 mg as slow injection, may further give 2 mg injections as necessary. Max dose: 10 mg.
Elderly: Reduce dose as necessary.

Intravenous
Cardiac arrhythmias
Adult: Initially, 5 mg injected at a rate of 1-2 mg/minute, may be repeated if necessary at a 5-minute interval to a total dose of 10-15 mg.
Elderly: Reduce dose as necessary.

Oral
Angina pectoris
Adult: Conventional tab: 50-100 mg bid or tid. Extended-release: Initially, 100 mg daily, may be increased gradually at weekly intervals until satisfactory response is achieved. Max: 400 mg/day.
Elderly: Reduce dose as necessary.

Oral
Hypertension
Adult: Conventional tab: Initially, 100 mg daily as single or in 2 divided doses, may be increased weekly according to response. Maintenance: 200 mg daily in divided doses. Extended release tab: Initially, 25-100 mg daily, may be increased weekly according to response. Max: 400 mg/day.
Elderly: Reduce dose as necessary.

Oral
Adjunct in hyperthyroidism
Adult: Conventional tab: 50 mg qid, may be reduced once euthyroid state is achieved.
Elderly: Reduce dose as necessary.

Oral
Prophylaxis of migraine
Adult: Conventional tab: 100-200 mg daily in divided doses.
Elderly: Reduce dose as necessary.

Oral
Heart failure
Adult: Extended-release tab: 12.5-25 mg once daily, may be increased gradually as tolerated, at intervals of 2 weeks. Max dose: 200 mg once daily.
Elderly: Reduce dose as necessary.

Oral
Cardiac arrhythmias
Adult: Conventional tab: 50 mg bid or tid, may be increased to 300 mg daily in divided doses, as necessary.
Elderly: Reduce dose as necessary.
Special Patient Group
Metoprolol is metabolised predominantly by CYP2D6 isoenzyme. It exhibits stereoselective metabolism that is dependent on oxidation phenotype. CYP2D6 is absent in approximately 8% of Caucasians and about 2% of most other populations.

Poor, intermediate, extensive, and ultrarapid metabolisers of metoprolol have been identified and studies confirmed that plasma-metoprolol concentrations correlate with the metaboliser status. CYP2D6 poor metabolisers exhibit several-fold higher plasma concentrations of metoprolol than extensive metabolisers with normal CYP2D6 activity. Drugs that inhibit CYP2D6 are likely to increase metoprolol plasma concentration, thus decreasing its cardioselectivity.
Hepatic Impairment
Reduce dose.
Administration
May be taken with or without food.
Contraindications
2nd or 3rd degree atrioventricular block, decompensated cardiac failure, severe bradycardia, sick-sinus syndrome (without pacemaker), untreated phaeochromocytoma, severe peripheral arterial disease, and cardiogenic shock.
Special Precautions
Patient with 1st degree atrioventricular block, sinus node dysfunction, or conduction disorders, bronchospastic disease, diabetes mellitus, psoriasis, myasthenia gravis, thyrotoxicosis, peripheral vascular disease. Avoid abrupt withdrawal. Hepatic impairment. Elderly. Pregnancy and lactation. CYP2D6 ultrarapid and poor metabolisers.
Adverse Reactions
Significant: Bradycardia, atrioventricular block, hypotension.
Cardiac disorders: Dyspnoea, pulmonary oedema, palpitations.
Ear and labyrinth disorders: Tinnitus.
Eye disorders: Blurred vision, visual disturbances.
Gastrointestinal disorders: Nausea, vomiting, abdominal pain, constipation, flatulence, dry mouth, heartburn.
General disorders and administration site conditions: Fatigue.
Immune system disorders: Psoriasis.
Metabolism and nutrition disorders: Peripheral oedema.
Musculoskeletal and connective tissue disorders: Musculoskeletal pain.
Nervous system disorders: Headache.
Psychiatric disorders: Depression, confusion, nightmares, insomnia, hallucinations.
Respiratory, thoracic and mediastinal disorders: Bronchospasm.
Skin and subcutaneous tissue disorders: Photosensitivity, skin rash.
Vascular disorders: Orthostatic hypotension (occasionally with syncope), cold extremities.
IV/Parenteral/PO: C
Patient Counseling Information
This drug may cause dizziness, if affected, do not drive or operate machinery.
MonitoringParameters
Monitor blood pressure, heart rate, and ECG.
Overdosage
Symptoms: Severe hypotension, sinus bradycardia, atrioventricular block, heart failure, cardiogenic shock, bronchospasm, impairment of consciousness, coma, nausea, vomiting. Management: Symptomatic and supportive treatment. Consider treating patient with intensive care. Prevent absorption of any drug material that may still be present in the gastrointestinal tract by induction of vomiting, gastric lavage, or administration of activated charcoal and a laxative. Evaluate the need for atropine, adrenergic-stimulating drugs or pacemaker to treat bradycardia and conduction disorders. IV vasopressor infusions (e.g. norepinephrine, dopamine) may be given to treat hypotension. Bronchospasm can be reversed by bronchodilators.
Drug Interactions
May enhance cardiodepressant effect with anaesthetic drugs (e.g. cyclopropane). May enhance hypoglycaemic effects of insulin. Increased serum concentration with CYP2D6 inhibitors (e.g. quinidine, fluoxetine, paroxetine, propafenone). May increase atrioventricular conduction and decrease heart rate with digitalis glycosides, clonidine, diltiazem, verapamil. Additive effects with catecholamine-depleting drugs (e.g. reserpine) and MAO inhibitors. Increased blood pressure lowering effect with TCA, barbiturates, phenothiazines, and other antihypertensive agents. Reduced antihypertensive effects with NSAIDs (e.g. indometacin). May enhance vasoconstrictive action of ergot alkaloids.
Action
Description: Metoprolol selectively inhibits β1-adrenergic receptors but has little or no effect on β2-receptors except in high doses. It does not exhibit membrane stabilising or intrinsic sympathomimetic activity.
Onset: Oral: Within 1 hour (immediate release). IV: 20 minutes.
Duration: Oral: Dose-dependent (immediate release); approx 24 hours (extended release).
Pharmacokinetics:
Absorption: Rapidly and completely absorbed. Bioavailability: Approx 40-50% (immediate release); 77% (extended release). Time to peak plasma concentration: 1.5-2 hours.
Distribution: Crosses the blood brain barrier and present in breastmilk in small amounts. Volume of distribution: 3.2-5.6 L/kg. Plasma protein-binding: Approx 12% to albumin.
Metabolism: Metabolised extensively in the liver via CYP2D6, undergoes first-pass effect (approx 50%).
Excretion: Via urine (95%; <5-10% as unchanged drug, increased to 30-40% in poor CYP2D6 metabolisers). Elimination half-life: 3-4 hours.
Chemical Structure

Chemical Structure Image
Metoprolol

Source: National Center for Biotechnology Information. PubChem Database. Metoprolol, CID=4171, https://pubchem.ncbi.nlm.nih.gov/compound/Metoprolol (accessed on Jan. 22, 2020)

Storage
Store below 25°C.
MIMS Class
ATC Classification
C07AB02 - metoprolol ; Belongs to the class of selective beta-blocking agents. Used in the treatment of cardiovascular diseases.
References
Blake CM, Kharasch ED, Schwab M, et al. A Meta-Analysis of CYP2D6 Metabolizer Phenotype and Metoprolol Pharmacokinetics. Clin Pharmacol Ther. 2013 Sep;94(Suppl 3):394-9. doi: 10.1038/clpt.2013.96. Accessed 03/12/2019

Li S, Lin H, Sun W, et al. A Meta-analysis of the Effect of CYP2D6 Polymorphism on the Pharmacokinetics and Pharmacodynamics of Metoprolol. Int J Clin Pharmacol Ther. 2017 Jun;55(6):483-492. doi: 10.5414/CP202545. Accessed 03/12/2019

Annotation of FDA Label for Metoprolol and CYP2D6. Pharmacogenomics Knowledgebase (PharmGKB). https://www.pharmgkb.org/. Accessed 03/12/2019.

Annotation of Swissmedic Label for Metoprolol and CYP2D6. Pharmacogenomics Knowledgebase (PharmGKB). https://www.pharmgkb.org/. Accessed 03/12/2019.

Anon. CYP2D6-Metoprolol (Pharmacogenomics). Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 03/12/2019.

Anon. Metoprolol. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 18/03/2019.

Buckingham R (ed). Metoprolol. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 18/03/2019.

Clinical Annotation for CYP2D6 and Metoprolol. Pharmacogenomics Knowledgebase (PharmGKB). https://www.pharmgkb.org/. Accessed 03/12/2019.

Joint Formulary Committee. Metoprolol Tartrate. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 09/12/2013.

Lopressor Tablets and Ampules for Injection. U.S. FDA. https://www.fda.gov/. Accessed 09/12/2013.

McEvoy GK, Snow EK, Miller J et al (eds). Metoprolol Succinate, Metoprolol Tartrate. AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com. Accessed 09/12/2013.

Metoprolol Extended Release Tab (BluePoint Laboratories). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 18/03/2019.

Metoprolol Injection (Baxter Healthcare Corporation). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 18/03/2019.

Metoprolol Tartrate Injection (Fresenius Kabi USA, LLC). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 03/12/2019.

Toprol XL (AstraZeneca). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 09/12/2013.

Disclaimer: This information is independently developed by MIMS based on Metoprolol 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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