Medication: Beta-blockers

What are beta-blockers?

The term “beta-blockers” refers to a group of medications that includes propranolol, bisoprolol, and metoprolol, among others. These drugs are primarily used to treat patients with high blood pressure, angina, or irregular heart rhythms, but they can be used “off-label” in the treatment of PoTS.

What does “off-license” mean?

In the UK, beta-blockers are considered “off-license” for PoTS because this is not one of their officially approved uses. Many doctors still prescribe them for PoTS because of the medication’s known benefits for some patients with the condition.

How do beta-blockers work?

Beta-blockers work by “blocking” specific sites (called beta-receptors) in the heart and blood vessels that are usually activated by stress hormones like adrenaline. Normally, adrenaline helps your heart pump faster, but when these receptors are blocked, the heart beats a bit more slowly and with less force.

Beta-blockers can be particularly helpful in patients with “hyperadrenergic” PoTS, where the effects of adrenaline and other stress hormones can cause symptoms such as palpitations, shaking, anxiety and light-headedness upon standing. By blocking these receptors, beta-blockers can slow down the heart rate and reduce the heart’s response to stress hormones, which can make a big difference in how a person feels when they stand up. Some studies have shown that they may improve exercise ability in patients with PoTS.

Beta-blockers work best when combined with other conservative (non-drug) strategies. These include wearing compression garments to help blood circulate better, drinking more fluids, and staying active with regular exercise.

How do I take them?

Each individual medication may differ, but most beta-blockers for PoTS are taken once or twice daily in the form of a tablet. They can be taken with or without food, but it’s important to take them at the same time each day to maintain steady levels of the medicine in the bloodstream.

Typically, doctors will start with a low dose and gradually increase it if necessary. Research indicates that higher doses do not necessarily result in better outcomes and may increase the risk of side effects. Beta-blockers can lower blood pressure if taken at higher doses. 

It’s important to avoid stopping beta-blockers abruptly, as this can lead to serious complications. If you intend to stop taking beta-blockers, discuss it with your doctor, who can assist you in gradually tapering off the medication.

Who should not take them?

Beta-blockers are not suitable for everyone. They should not be taken by patients with asthma or other respiratory issues – they may worsen these conditions by blocking the beta receptors in the lungs.

Those with a very low heart rate or certain heart rhythm problems should also avoid beta-blockers.

In some cases, those under 18 may use beta-blockers, but this should be done under medical supervision.

If you are pregnant or planning to become pregnant, it’s worth noting that while some beta-blockers can be used safely during pregnancy; the decision should always involve a detailed discussion with your doctor. Labetalol is often the first-line choice in pregnant patients.

Beta-blockers can interact with a variety of other medications, potentially reducing their effectiveness or increasing the risk of side effects. Before starting any new medication, it’s important to discuss all current medications and supplements you are taking with your doctor.

What are the side effects?

Common side effects include:

• feeling tired
• dizziness
• cold extremities (hands and feet)
• slower heart rate
• gastrointestinal upset

It is important to inform your doctor if you notice any bothersome side effects. They may be able to adjust the dosage or try a different medication that works better for you.

Serious side effects include difficulty breathing, heart problems, and allergic reactions. Seek emergency medical attention if you experience these or any other serious side effects.

Monitoring

Regular checks can help your doctor evaluate how well the medication is working and if any complications arise. This may include checking your heart rate and blood pressure, as well as conducting heart tests like an ECG. Keeping a diary to track symptoms can also be incredibly useful, as it can highlight patterns and show how well you are responding to the medication. Like any medication, they may not work for everyone, and it is important to speak to your doctor about your options.

How do I obtain them?

Since beta-blockers are not licensed for PoTS in the UK, they are generally prescribed by a hospital doctor, or a GP who has specific experience using them to treat PoTS. They may be obtained via a private or NHS prescription.

How to store them

Beta-blockers should be stored in a cool, dry place, away from direct sunlight and out of reach of children. It is best to keep the medication in its original packaging to protect it from light and moisture. The medication must be used before its expiry date.

If your doctor prescribes beta-blockers for you, please read the patient information leaflet that comes with the medication for more detailed guidance.

Please note this is a brief summary of beta-blockers, and it is not a substitute for advice from your healthcare professional.