Maximum Total Dosing of IV Metoprolol Tartrate
The maximum total dose of intravenous metoprolol tartrate is 15 mg, administered as three separate 5 mg boluses given at 2-5 minute intervals. 1, 2, 3
Standard IV Dosing Protocol
- Administer the first 5 mg bolus slowly over 1-2 minutes 1, 2, 3
- Wait 5 minutes between each dose while monitoring hemodynamic response 1, 2
- Repeat with a second 5 mg bolus if tolerated 1, 2
- Administer a third 5 mg bolus after another 5-minute interval if needed 1, 2
- Never exceed 15 mg total IV dose in any clinical scenario 1, 2, 3
The FDA label explicitly states this dosing regimen for acute myocardial infarction, specifying three bolus injections of 5 mg each at approximately 2-minute intervals. 3 This same maximum applies across all indications including supraventricular tachycardia and atrial fibrillation with rapid ventricular response. 1
Critical Pre-Administration Contraindications
Before administering any IV metoprolol, you must exclude:
- Heart failure signs: Rales, low output state, or decompensated heart failure 1, 2, 3
- Hemodynamic instability: Systolic BP <100-120 mmHg 1, 2
- Bradycardia or extreme tachycardia: Heart rate <60 bpm or >110 bpm 1, 2
- Conduction abnormalities: PR interval >0.24 seconds, second or third-degree AV block 1, 2, 3
- Respiratory disease: Active asthma or reactive airway disease 1, 2, 3
- Age and risk factors: Patients >70 years with multiple risk factors for cardiogenic shock 1
Required Monitoring During Administration
- Continuous ECG monitoring throughout the entire administration period 1, 2
- Blood pressure measurement before each bolus and frequently thereafter 1, 2, 3
- Continuous heart rate monitoring 1, 2
- Auscultation for rales (pulmonary congestion) after each dose 1, 2
- Auscultation for bronchospasm after each dose 1, 2
The FDA label emphasizes that parenteral metoprolol must be administered in a setting with intensive monitoring capabilities. 3
Transition to Oral Therapy
- Begin oral metoprolol tartrate 15 minutes after the last IV dose 1, 3
- For patients tolerating the full 15 mg IV dose: Start 50 mg orally every 6 hours for 48 hours 1, 3
- For patients with partial intolerance: Start 25 mg orally every 6 hours 3
- After 48 hours, transition to maintenance dosing of 100 mg twice daily 3
Critical Pitfall to Avoid
Never administer the full 15 mg as a single rapid bolus. 1 This significantly increases the risk of severe hypotension, bradycardia, and cardiogenic shock. The incremental dosing strategy with monitoring between doses allows for early detection of adverse effects and prevents overdosing. 1, 2
Alternative for High-Risk Patients
For patients at elevated risk of adverse effects (elderly, borderline hemodynamics, multiple comorbidities), consider esmolol instead: