Metoprolol: 10 Side Effects You Should Know About—and When to Call Your Doctor

Metoprolol is a commonly prescribed beta-blocker used for conditions such as high blood pressure, angina, certain heart-rhythm problems, and heart failure. It works by slowing the heart rate and reducing the heart’s workload.

Most people tolerate it well, but side effects can occur. Knowing what is relatively common—and what deserves medical attention—can help you use the medication safely.

1. Tiredness

Feeling unusually tired or lacking energy is a common complaint, particularly when first starting metoprolol or after a dose increase. It may improve as your body adjusts.

If fatigue is severe or continues to interfere with daily life, discuss it with your doctor.

2. Dizziness or lightheadedness

Metoprolol can lower blood pressure and heart rate, which may make some people feel dizzy, especially when standing up.

Sit or lie down if you feel faint, and contact your healthcare professional if the problem is persistent or severe.

3. Slow heartbeat

A slower pulse is an expected effect of metoprolol, but an excessively slow heart rate can become a problem.

Seek medical advice if a slow pulse occurs with weakness, dizziness, confusion, chest discomfort, or fainting.

4. Low blood pressure

Some people develop hypotension while taking metoprolol. Symptoms can include dizziness, weakness, blurred vision, or feeling faint.

Your clinician may need to check your blood pressure and medication dose.

5. Cold hands and feet

Because beta-blockers affect circulation, some people notice that their hands or feet feel colder than usual.

This is usually not dangerous, but mention persistent or troublesome symptoms at your next medical appointment.

6. Sleep problems or unusual dreams

Some people report insomnia, sleep disturbances, or vivid dreams while taking metoprolol.

If these symptoms become persistent or significantly affect your sleep, tell your doctor rather than stopping the medication yourself.

7. Nausea or diarrhea

Digestive symptoms can occur. They’re generally mild, but persistent vomiting or diarrhea can cause dehydration and may require medical advice.

8. Shortness of breath or wheezing

New or worsening breathing difficulty should not simply be dismissed as a medication side effect.

Contact your healthcare professional promptly, particularly if you have a history of asthma or other breathing problems.

Severe difficulty breathing is an emergency.

9. Swelling or unexpected weight gain

Swelling in the ankles or legs, particularly when accompanied by rapid weight gain or increasing shortness of breath, can be a warning sign of fluid retention or worsening heart failure.

Contact your doctor promptly if these symptoms develop.

10. Fainting or an unusual heartbeat

Fainting, a markedly irregular heartbeat, or a rapid or pounding heartbeat should be taken seriously.

These symptoms can have several causes and may require urgent assessmentThe bottom line

Metoprolol can cause side effects such as fatigue, dizziness, low blood pressure, and a slower heartbeat, but many people take it safely and successfully.

The key is knowing the difference between an expected side effect and a warning sign. Fainting, serious breathing problems, significant swelling, chest pain, or a concerning heartbeat deserve prompt medical attention.

Don’t change your dose or stop metoprolol based on an online article. Your prescribed dose is individualized for your condition, heart rate, blood pressure, and other medications.