Hold Parameters for Metoprolol Tartrate
Metoprolol tartrate should be held if the heart rate is below 50 beats per minute (bpm) or if systolic blood pressure is below 100 mmHg to prevent adverse cardiovascular outcomes. 1
Specific Hold Parameters
Heart Rate Parameters:
- Hold if heart rate < 50 bpm 1
- Delay administration by 12 hours if heart rate is consistently 45-49 bpm 1
- For IV administration, hold if heart rate drops below 50 bpm 1
Blood Pressure Parameters:
- Hold if systolic blood pressure < 100 mmHg 1
- For IV administration, hold if systolic blood pressure drops below 100 mmHg 1
Clinical Rationale for Hold Parameters
These hold parameters are critical because:
Mortality Risk: In the POISE trial, clinically significant bradycardia was associated with an adjusted odds ratio for death and stroke of 2.13 (95% CI 1.37 to 3.12) 1
Stroke Risk: Clinically significant hypotension was associated with an adjusted odds ratio for death and stroke of 4.97 (95% CI 3.62 to 6.81) 1
Increased Adverse Events: Meta-analyses have shown that perioperative beta blockade is associated with increased incidence of:
- Bradycardia (OR 3.49,95% CI 2.4 to 5.9)
- Congestive heart failure (OR 1.68,95% CI 1.00 to 2.8) 1
Alternative Causes of Tachycardia
When a patient on metoprolol has persistent tachycardia despite therapy, consider alternative causes before increasing the dose:
- Sepsis
- Hypovolemia
- Pulmonary embolism
- Anemia
These conditions may warrant short-term down-titration or even discontinuation of beta-blocker therapy rather than dose increases 1.
Monitoring During Administration
During IV administration of metoprolol tartrate:
- Monitor blood pressure continuously
- Monitor heart rate continuously
- Perform continuous electrocardiogram monitoring 2
Special Considerations
Perioperative Setting: Continuation of beta-blocker therapy in the perioperative period is a Class I indication, but titration should maintain effective heart rate control while avoiding bradycardia and hypotension 1
Target Heart Rate: An absolute mean perioperative heart rate lower than 70 bpm is associated with better outcomes, but must be balanced against the risks of excessive bradycardia 1
Pulmonary Concerns: In patients with reactive airway disease, monitor closely for signs of bronchospasm, as metoprolol may affect pulmonary function, particularly at higher doses 3
By adhering to these hold parameters, clinicians can maximize the benefits of metoprolol therapy while minimizing the risks of adverse cardiovascular outcomes.