Metoprolol is a beta-blocker commonly prescribed for conditions such as high blood pressure, certain heart rhythm problems, angina, and some forms of heart failure. It works by slowing the heart rate and reducing the workload on the heart.
Like all medications, metoprolol can cause side effects. Many are mild and improve as your body adjusts, but some require medical attention.
1. Slow Heart Rate
Because metoprolol intentionally slows the heart, some people may develop a heart rate that is lower than usual. A mildly slower pulse may be expected, but severe or symptomatic slowing can cause weakness, dizziness, or fainting.
2. Low Blood Pressure
Metoprolol can lower blood pressure. If your blood pressure drops too much, you may experience:
- Dizziness
- Lightheadedness
- Weakness
- Blurred vision
- Fainting
Getting up slowly from a sitting or lying position may help reduce dizziness.
3. Tiredness and Fatigue
Feeling unusually tired or lacking energy is one of the more commonly reported effects. This can happen because metoprolol reduces heart rate and decreases the body’s cardiovascular response to activity.
4. Dizziness
Some people experience dizziness, particularly when starting treatment or after the dose is increased. It may become more noticeable when standing suddenly.
If you feel dizzy, sit or lie down until it passes and avoid driving until you know how the medication affects you.
5. Cold Hands and Feet
Metoprolol can reduce circulation to the extremities in some people, resulting in hands or feet that feel unusually cold.
Keeping your extremities warm can help, but persistent or severe circulation problems should be discussed with a healthcare professional.
6. Shortness of Breath or Breathing Problems
Although uncommon, breathing difficulties can occur, particularly in people who have asthma or other airway conditions. Wheezing, significant shortness of breath, or difficulty breathing should not be ignored.
7. Sleep Problems or Vivid Dreams
Some people report difficulty sleeping, unusual dreams, or nightmares while taking metoprolol. These effects aren’t experienced by everyone and may improve over time.
If sleep disturbances become persistent or interfere with daily life, tell your prescriber.
8. Depression or Mood Changes
Mood changes, including feeling unusually down or less motivated, have been reported with beta-blockers. If you notice persistent changes in mood, anxiety, or other significant psychological symptoms after starting metoprolol, discuss them with your healthcare provider.
9. Nausea, Diarrhea, or Stomach Upset
Metoprolol can sometimes cause gastrointestinal symptoms such as nausea, diarrhea, or abdominal discomfort. Taking the medication exactly as prescribed and, when appropriate, with food may help.
10. Sexual Problems
Some people taking beta-blockers experience sexual side effects, including reduced sexual desire or difficulty achieving or maintaining an erection. If this occurs, don’t stop the medication on your own. Your healthcare provider may be able to adjust the dose or consider another treatment.
When Metoprolol Side Effects May Be Serious
Seek urgent medical attention if you develop symptoms such as:
- Fainting or severe dizziness
- Very slow or irregular heartbeat
- Severe shortness of breath or wheezing
- Chest pain
- New or worsening swelling
- Confusion or extreme weakness
- Signs of a serious allergic reaction, such as swelling of the face or throat or difficulty breathing
Important: Don’t Stop Metoprolol Suddenly
One of the most important precautions with metoprolol is not to stop taking it suddenly unless your healthcare professional tells you to do so. Abruptly stopping a beta-blocker can cause a dangerous increase in heart rate and blood pressure and may worsen heart-related problems in some people.
If you are experiencing side effects, contact your prescriber rather than stopping the medication yourself.
Bottom line: Metoprolol can be an effective medication, but side effects such as fatigue, dizziness, slow heart rate, low blood pressure, cold extremities, and sleep disturbances can occur. Serious symptoms—especially fainting, severe breathing problems, or significant changes in heart rhythm—need prompt medical evaluation.