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Can I take Bisoprolol and Losartan together?

Drug interaction guide

Taking bisoprolol and losartan together can cause your blood pressure to drop lower than intended. This may make you feel dizzy, lightheaded, or faint, especially when standing up quickly. It can also lead to increased levels of potassium in your blood.

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Why this happens

Both medicines work to lower blood pressure but in different ways. Bisoprolol is a beta-blocker that slows the heart rate, while losartan is an angiotensin II receptor blocker (ARB) that relaxes blood vessels. When used together, their effects add up (additive effect). Additionally, both can affect how your kidneys handle potassium.

It is very common for doctors to prescribe these two medicines together, but you should be monitored closely. Your doctor will likely perform regular blood tests to check your kidney function and potassium levels. To avoid dizziness, try to get up slowly from a sitting or lying position. If you feel very dizzy, have a racing heart, or feel unusually tired, contact your GP.

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Pregnancy

You must not take losartan if you are pregnant or planning to become pregnant, as it can cause serious harm or death to an unborn baby. Use effective contraception while taking it.

Asthma or chronic obstructive pulmonary disease (COPD)

Bisoprolol can cause your airways to narrow, making it much harder to breathe or triggering a severe asthma attack. It is usually avoided if you have a history of wheezing or asthma.

Stopping treatment

Do not stop taking bisoprolol suddenly. Doing so can cause a dangerous rise in blood pressure or worsen heart conditions; it must be tapered off gradually under medical supervision.

Diabetes

Bisoprolol can mask the warning signs of low blood sugar (hypoglycaemia), such as a fast heartbeat or tremors. You will need to monitor your blood sugar more closely.

Alcohol

Drinking alcohol can increase the blood pressure-lowering effect of these medicines, which may make you feel dizzy, lightheaded, or faint, especially when you first start taking them or when your dose is increased. It is best to keep your alcohol intake within recommended limits and see how the medicine affects you before drinking.

Salt substitutes (Potassium-based)

Losartan can increase the levels of potassium in your blood. Many salt substitutes (such as Lo-Salt) contain potassium chloride instead of sodium. Using these while taking Losartan can lead to dangerously high potassium levels (hyperkalaemia). You should avoid using potassium-based salt substitutes unless your doctor tells you otherwise.

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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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