Metoprolol is a beta-blocker used for conditions including high blood pressure, irregular heart rhythms, angina, and some heart conditions. Most people tolerate it well, and common side effects are generally mild. (nhs.uk)
10 side effects to know about
- Tiredness or fatigue — especially when starting treatment.
- Dizziness or lightheadedness — metoprolol can lower blood pressure and slow the heart rate.
- Weakness — sometimes related to its effect on heart rate and blood pressure.
- Headache — commonly reported and often temporary.
- Nausea or feeling sick — usually mild.
- Cold hands or feet — beta-blockers can affect circulation to the extremities.
- Sleep problems or vivid dreams/nightmares — these can occur with beta-blockers.
- Shortness of breath or wheezing — more concerning, particularly in people with asthma or other lung disease.
- A very slow heartbeat or fainting — can indicate excessive slowing of the heart and requires medical assessment.
- Sexual difficulties — decreased libido or erectile problems have been reported, although they aren’t common and the evidence that metoprolol directly causes them isn’t definitive. (nhs.uk)
🚨 When to seek medical help
Contact a healthcare professional promptly if you develop fainting, significant breathing difficulty, worsening swelling or shortness of breath, or an unusually slow/irregular heartbeat. These can indicate a more serious problem. (nhs.uk)
If you have diabetes, there’s another important consideration: metoprolol can make some of the warning symptoms of low blood sugar harder to recognize. (nhs.uk)
Don’t stop metoprolol suddenly
This is particularly important if you’re taking it for a heart condition. Abruptly stopping metoprolol can worsen your condition, so any dose reduction or discontinuation should be planned with your doctor. (nhs.uk)
Bottom line: Feeling somewhat tired or dizzy when starting metoprolol can happen, but severe dizziness, fainting, breathing problems, or marked changes in heart rate should not be ignored.
