Metoprolol (Lopressor, Toprol - XL) Considerations for Use*

US/FDA Approved Indication: Heart Rate Control for Atrial Fibrillation

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Black Box Warning* Abrupt cessation may exacerbate angina pectoris and MI.

Mechanism of Action

Blocks binding of catecholamines to beta-1 receptors; Beta-1 selective

Dosing

Acute setting: 2.5 to 5 mg IV bolus over 2 minutes; may repeat every 5 minutes to a maximum dose of 15 mg

Non-acute setting or maintenance:
Metoprolol tartrate (immediate-release) : 25 to 100 mg PO twice daily
Metoprolol succinate (extended-release): 25 to 200 mg daily

Elderly: May need lower doses

Hepatic Impairment: May need lower doses

Renal Impairment: No dosage adjustment needed

Contraindications
  • AV block
  • Bradycardia
  • cardiogenic shock
  • decompensated heart failure
  • sick sinus syndrome
  • pheochromocytoma
  • Major Side Effects

    hypotension, heart block, bradycardia, bronchospasm , HF

    Dosage forms and Strengths

    PO:
    25 mg, 50 mg, 100 mg immediate-release tablets (tartrate)
    25 mg, 50 mg, 100 mg, 200 mg extended-release tablets (succinate)

    IV: 5 mL ampules (1 mg/mL)

    Special Notes

    Abrupt cessation my precipitate angina, MI, arrhythmias, or rebound HTN; discontinue by tapering over 1-2 weeks.

    Immediate-release form is metoprolol tartrate; extended-release form is metoprolol succinate. When switching from immediate release to extended-release product, use same total daily dose. The immediate and extended release products may not give same clinical response on mg:mg basis; monitor response and side effects when interchanging between metoprolol products.

    Concomitant amiodarone, digoxin, disopyramide, or non-dihydropyridine calcium channel blockers may increase the risk of bradycardia.

    Monitor closely for HF exacerbation and hypotension when titrating dose.

    Counseling

     

    * Refer to prescribing information for more complete information.
    †Dosages given in the table may differ from those recommended by the manufacturers.


    Sources:

    1. American College of Cardiology (ACC), American Heart Association (AHA), and the European Society of Cardiology (ESC). ACC/AHA/ESC 2006 Guidelines for the Management of Patients with Atrial Fibrillation. Washington, DC: American College of Cardiology.
    2. Heart Rhythm Society. AF360 Pocket Guide: Practical Rate and Rhythm Management of Atrial Fibrillation. 2010, Washington, DC: Heart Rhythm Society.
    3. Tarascon Pocket Pharmacopoeia® 2012.