From the FDA Drug Label
Metoprolol is contraindicated in patients with ... systolic blood pressure < 100 mmHg; The level of blood pressure at which you should withhold metoprolol is a systolic blood pressure < 100 mmHg.
- Withhold metoprolol if the patient's systolic blood pressure is less than 100 mmHg 1.
From the Research
Metoprolol should generally be withheld if the systolic blood pressure is below 90 mmHg or if the heart rate is less than 50-60 beats per minute. This recommendation applies to both immediate-release and extended-release formulations of metoprolol. If a patient on metoprolol develops hypotension, the medication should be temporarily discontinued and the patient should be monitored until blood pressure normalizes. Once blood pressure has stabilized above 90 mmHg systolic, metoprolol can be cautiously reintroduced, potentially at a lower dose. The reason for this threshold is that beta blockers like metoprolol work by blocking beta-adrenergic receptors, which reduces heart rate and contractility, potentially exacerbating hypotension.
In patients with heart failure, slightly lower blood pressures might be tolerated under specialist supervision, but the 90 mmHg threshold remains a reasonable general guideline. Always consider the clinical context, including the indication for metoprolol and the patient's overall condition, when making decisions about withholding or resuming the medication. According to the most recent study 2, there was a significant difference in occurrence of hypotension in patients receiving diltiazem compared to metoprolol, with more patients in the diltiazem group experiencing hypotension. However, the study also noted that the definition of hypotension included systolic blood pressure < 90 mmHg or diastolic blood pressure < 60 mmHg, which supports the recommended threshold for withholding metoprolol.
Key points to consider when deciding to withhold metoprolol include:
- Systolic blood pressure below 90 mmHg
- Heart rate less than 50-60 beats per minute
- Clinical context, including indication for metoprolol and patient's overall condition
- Potential for hypotension, particularly in patients with heart failure or those receiving other medications that may exacerbate hypotension.
It is essential to prioritize the patient's safety and adjust the treatment plan accordingly, taking into account the most recent and highest quality evidence available 2.