What is the administration rate for intravenous (IV) metoprolol (Lopressor)?

From the Guidelines

Intravenous metoprolol should be administered at a rate of 5 mg over 1 to 2 minutes, with the dose repeated every 5 minutes for a maximum of three doses (total 15 mg). This recommendation is based on the most recent and highest quality study available, which provides guidance on the administration of IV metoprolol for various cardiac conditions 1. The dosing regimen is crucial to minimize the risk of adverse effects, such as bradycardia and hypotension, while effectively managing the patient's condition.

Key Considerations

• The medication should be given as a slow IV push to allow monitoring for adverse effects between doses.
• After administering each 5 mg dose, assess the patient's heart rate, blood pressure, and ECG before proceeding with additional doses.
• Metoprolol IV is typically used for acute situations like supraventricular tachyarrhythmias, acute myocardial infarction, or perioperative hypertension.
• Contraindications include severe bradycardia, heart block, cardiogenic shock, or decompensated heart failure, so assess for these conditions before administration.

Additional Guidance

• The choice of beta blocker for an individual patient is based primarily on pharmacokinetic and side effect criteria, as well as on physician familiarity 1.
• Monitoring during intravenous beta-blocker therapy should include frequent checks of heart rate and blood pressure and continuous ECG monitoring, as well as auscultation for rales and bronchospasm.
• The target resting heart rate is 50 to 60 beats per minute unless a limiting side effect is reached.
• Selection of the oral agent should include the clinician’s familiarity with the agent.
• Maintenance doses should be given according to established guidelines, with careful consideration of the patient's response to the medication and potential side effects.

From the FDA Drug Label

DOSAGE & ADMINISTRATION Myocardial Infarction Early Treatment During the early phase of definite or suspected acute myocardial infarction, initiate treatment with metoprolol tartrate as soon as possible after the patient’s arrival in the hospital. Such treatment should be initiated in a coronary care or similar unit immediately after the patient’s hemodynamic condition has stabilized Begin treatment in this early phase with the intravenous administration of three bolus injections of 5 mg of metoprolol tartrate injection each; give the injections at approximately 2-minute intervals. The administration rate for intravenous (IV) metoprolol (Lopressor) is approximately 2-minute intervals for three bolus injections of 5 mg each, for a total dose of 15 mg 2.

• The injections should be given in a setting with intensive monitoring.
• Monitoring of blood pressure, heart rate, and electrocardiogram is required during the intravenous administration of metoprolol tartrate injection.

From the Research

Administration Rate for Intravenous (IV) Metoprolol

• The administration rate for IV metoprolol can vary depending on the specific clinical scenario and patient population.
• According to the study by the Phase IV Metoprolol in Myocardial Infarction Study Group 3, the full intravenous dose of metoprolol was 15 mg.
• In the study by 4, the median dose of initial intervention was 5 mg for metoprolol.
• The study by 5 used a metoprolol infusion at a dose of 1-5 mcg/kg/min for children with hypertensive emergencies.
• The study by 6 evaluated a combined i.v. and oral dosage regimen of metoprolol, with an initial i.v. dose of 15 mg in three divided doses.
• The METOCARD-CNIC trial 7 used early IV metoprolol administration before reperfusion, but the specific dose is not mentioned in the provided text.

Key Findings

• The studies suggest that IV metoprolol can be effective in various clinical scenarios, including acute myocardial infarction 3, 7, atrial fibrillation 4, and hypertensive emergencies in children 5.
• The administration rate and dose of IV metoprolol may need to be tailored to the individual patient and clinical scenario.
• Further research may be needed to fully establish the optimal administration rate and dose of IV metoprolol in different clinical contexts.