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Can I take Magnesium and Bisoprolol together?

Drug interaction guide

Taking magnesium and bisoprolol together can lead to an excessively slow heart rate or a significant drop in blood pressure. This may cause you to feel dizzy, lightheaded, or faint.

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Why this happens

Both magnesium and bisoprolol (a beta-blocker) can slow down the electrical signals in your heart and relax your blood vessels. When used together, these effects can add up, making your heart beat too slowly or lowering your blood pressure more than intended.

You should consult your doctor before taking magnesium supplements with bisoprolol. If your doctor approves the combination, monitor your pulse and blood pressure regularly. Seek medical advice if you feel unusually tired, dizzy, or if you notice your heart rate is very slow. To avoid any potential issues with how the medicine is absorbed, it is also sensible to space the doses apart by at least 2 hours.

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Asthma or COPD

Bisoprolol can cause severe breathing difficulties or trigger a life-threatening asthma attack. Do not take this medicine if you have a history of asthma or severe wheezing.

Stopping treatment suddenly

Never stop taking bisoprolol abruptly. Doing so can cause a rapid heart rate, severe chest pain, or a heart attack. Your dose must be reduced gradually by a doctor.

Kidney disease

If you have severe kidney problems, your body may not be able to remove excess magnesium, leading to dangerously high levels in the blood. Check with your doctor before use.

Diabetes

Bisoprolol can hide the early warning signs of low blood sugar (hypoglycaemia), such as a fast heartbeat or tremors. You should monitor your blood sugar levels more closely.

Alcohol

It is best to avoid or strictly limit alcohol while taking bisoprolol. Alcohol can increase the blood-pressure-lowering effect of the medicine, which may make you feel dizzy, lightheaded, or faint, especially when you stand up.

It is best to avoid or strictly limit alcohol when taking magnesium. Alcohol acts as a diuretic, which can increase the amount of magnesium your body loses through urine, potentially making the supplement less effective. Additionally, chronic alcohol use can lead to magnesium deficiency.

Dairy products (Milk, Cheese, Yoghurt)

Avoid taking magnesium supplements at the same time as large amounts of dairy products. Dairy is high in calcium, and high doses of calcium can compete with magnesium for absorption in the gut, meaning you may not get the full benefit of your supplement. It is best to space them at least 2 hours apart.

Caffeine (Coffee, Tea, Energy drinks)

Limit your intake of caffeine (found in coffee, tea, and energy drinks). Caffeine can increase your heart rate and blood pressure, which may counteract the intended effects of bisoprolol.

It is best to limit caffeine intake around the time you take magnesium. Like alcohol, caffeine has a mild diuretic effect and can increase the excretion of magnesium through the kidneys.

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Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.

Disclaimer

This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.

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Article history

The information on this page is written and peer reviewed by qualified clinicians.

  • 25 Jan 2026 | Originally published
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