What BP Should You Not Give Metoprolol? A Clinical Guide

October 7, 2025 •

3 min read

In the United States, beta-blockers like metoprolol are prescribed to over 18% of patients treated for hypertension. Knowing what BP you should not give metoprolol is critical for preventing adverse events like severe hypotension and bradycardia.

Quick Summary

This guide details the specific blood pressure and heart rate thresholds for withholding metoprolol, outlines absolute and relative contraindications, and explains the clinical judgment necessary for safe administration.

Key Points

Blood Pressure Threshold: Metoprolol should not be given if systolic blood pressure is below 100 mmHg.
Heart Rate Threshold: Withhold metoprolol if the heart rate is less than 50-60 beats per minute (bpm).
Absolute Contraindications: Key contraindications include severe bradycardia, second- or third-degree heart block (without a pacemaker), and decompensated heart failure.
Relative Contraindications: Use with caution in patients with asthma, diabetes, and severe peripheral vascular disease.
Mechanism of Action: Metoprolol is a beta-1 selective blocker that lowers heart rate, blood pressure, and cardiac output.
Patient Monitoring: Frequent monitoring of blood pressure, heart rate, and signs of heart failure is crucial during therapy.
Abrupt Discontinuation: Suddenly stopping metoprolol can cause serious cardiac events like angina or heart attack.

Understanding Metoprolol and Its Role

Metoprolol is a widely used beta-blocker that primarily works by blocking beta-1 receptors in the heart, leading to decreased heart rate, reduced contraction force, and lower cardiac output. These actions help to decrease blood pressure.

The FDA has approved metoprolol for various cardiovascular conditions, including hypertension, angina pectoris, heart failure, and post-myocardial infarction. Because of its significant impact on the cardiovascular system, healthcare professionals must be aware of when it's unsafe to administer.

The Critical Question: What BP and Heart Rate Are Too Low for Metoprolol?

Deciding when to withhold metoprolol hinges on specific vital sign parameters, particularly low blood pressure (hypotension) and a slow heart rate ( bradycardia).

Blood Pressure Thresholds

A primary reason to withhold metoprolol is a systolic blood pressure (SBP) less than 100 mmHg. In some cases, like acute myocardial infarction, an SBP below 90 mmHg is a contraindication. Giving metoprolol with low SBP can worsen hypotension and impair organ perfusion.

Heart Rate Thresholds

Metoprolol should also generally be withheld if the heart rate is below 50-60 beats per minute (bpm). The FDA label specifies a contraindication for heart rates below 45 bpm for the injectable form. Metoprolol can further slow a low heart rate, potentially causing symptomatic bradycardia or heart block. Nurses are often advised to check an apical pulse and hold the drug if the rate is under 50 bpm.

Absolute and Relative Contraindications

Certain underlying conditions also dictate when metoprolol should not be used.

Absolute Contraindications

Metoprolol should be avoided entirely in the following conditions:

Severe bradycardia
Second- or third-degree heart block without a pacemaker
Decompensated heart failure
Cardiogenic shock
Sick sinus syndrome (without a pacemaker)
Known allergy to metoprolol or other beta-blockers

Relative Contraindications and Precautions

Use metoprolol cautiously and with close monitoring in these situations:

Asthma and Lung Disease: Higher doses can potentially affect lung beta-2 receptors.
Diabetes: Beta-blockers can mask hypoglycemia symptoms.
Peripheral Vascular Disease: May worsen symptoms.
Liver Disease: Increased risk of side effects due to impaired metabolism.

Comparison of Common Beta-Blockers

Beta-blockers have varying properties.


Feature	Metoprolol (Succinate/Tartrate)	Carvedilol (Coreg)	Atenolol (Tenormin)
Selectivity	Beta-1 Selective	Non-selective with Alpha-1 blocking	Beta-1 Selective
Vasodilation	No primary	Yes	No
Lipid Solubility	Moderate to high	Low	Low
Common Use in Diabetes	Use with caution	Often preferred	Use with caution
Common Use in Asthma	May be preferred	More likely to cause wheezing	Generally preferred

Side Effects and Patient Monitoring

Common side effects of metoprolol include dizziness, tiredness, diarrhea, and slow heartbeat. Serious effects can involve worsening heart failure, severe hypotension, and heart block.

Monitoring blood pressure and heart rate is essential during therapy. Patients should be advised on monitoring their pulse and blood pressure, changing positions slowly, and the dangers of abrupt discontinuation.

Conclusion

Knowing what BP you should not give metoprolol is crucial for patient safety. Withholding parameters include an SBP below 100 mmHg and a heart rate below 50-60 bpm. Absolute contraindications like decompensated heart failure and high-degree heart block are also critical considerations. Thorough patient assessment, including vital signs and co-morbidities, is key to the safe use of metoprolol. Always consult a healthcare professional for medical advice. You can find more information in the official FDA drug label.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional before making any decisions about your health or medications. U.S. Food and Drug Administration

Frequently Asked Questions

Before administering metoprolol, you must check the patient's blood pressure and heart rate. Hold the medication if the systolic blood pressure is less than 100 mmHg or the heart rate is below 50-60 bpm.

A systolic blood pressure of 105 mmHg is generally above the 90-100 mmHg cutoff for withholding metoprolol. However, clinical judgment is necessary. You must also check the heart rate and the patient's overall clinical condition before administering.

Giving metoprolol to a patient with already low blood pressure (hypotension) can cause it to drop to dangerous levels, leading to dizziness, fainting, and inadequate blood flow to vital organs.

Metoprolol reduces the heart's pumping force (negative inotropic effect). In decompensated heart failure, the heart is already failing to pump effectively, and metoprolol can worsen this condition, leading to further decline.

Metoprolol should be used with caution in patients with asthma. Although it primarily targets beta-1 receptors in the heart, it can affect beta-2 receptors in the lungs at higher doses, potentially causing airway tightening (bronchospasm).

If you miss a dose, take it as soon as you remember, as long as it is more than 8 hours before your next scheduled dose. Do not double up on doses. Never stop taking metoprolol abruptly without consulting your doctor.

The most common side effects of metoprolol include tiredness, dizziness, diarrhea, depression, shortness of breath, and a slow heartbeat (bradycardia).

Metoprolol immediate-release tablets should be taken with or immediately after a meal to enhance absorption. The extended-release versions can be taken with or without food.