What side effects can you get with blood pressure tablets?

Starting a new medicine or medicines to treat high blood pressure (hypertension) can be worrying as you do not know how they will make you feel.

As with all medicines, it can take time to get to the correct dose to help bring your blood pressure down to reach your target blood pressure, and you may need to try different medicines or a combination of medicines to get the right ones for you.

There’s also a possibility of side effects.

However, it’s important to remember that just because side effects can happen, it does not mean they will, and many people who take medicines for their blood pressure have no side effects at all.

Discuss any concerns you have with your doctor, so they can create a plan to monitor how well your medicines are working and to address any problems.

What are common blood pressure medicines?

Many different medicines are used to treat high blood pressure – below are some of the common ones:

• Beta blockers
  These drugs end in ‘olol’ like bisoprolol and labetalol. They can lower high blood pressure by slowing down the rate and force of your heartbeat.
• ACE inhibitors (angiotensin converting enzyme inhibitors)
  These drugs tend to end in ‘pril’ like ramipril and lisinopril. They help lower blood pressure by blocking enzymes that create the hormone that causes blood vessels to narrow (constrict). This helps the blood vessels to relax and widen, lowering your blood pressure.
• ARBs (angiotensin receptor blockers)
  These drugs tend to end with ‘artan’ like losartan and candesartan. They work similarly to ACE inhibitors, controlling the hormones that affect blood pressure, so it is unusual to take ACE inhibitors and ARBs at the same time.
  They are sometimes prescribed if you have had side effects to ACE inhibitors, such as a persistent dry cough.
• Calcium channel blockers
  These drugs end with ‘pine’ like amlodipine. They help to relax the artery walls, making them wider, which allows more blood to pass through, lowering blood pressure.
• Diuretics (water tablets)
  These are drugs like furosemide that help to remove excess fluid from the body, including from the blood meaning there is less pressure on the blood vessel walls.

What are the most common side effects? 

A lot of blood pressure medicines share the same side effects, but some are more common with certain medicines than others.

• Dizziness – it’s not unusual to feel dizzy or lightheaded when you first take blood pressure medicines as your blood pressure goes down, or if your dose is increased, because your body needs time to adjust to lower blood pressure.
• Headache – this can happen when your blood pressure drops.
• Dry cough – common with ACE inhibitors.
• Fatigue – common with beta-blockers.
• Swollen ankles – common with the calcium channel blocker amlodipine.

It’s also important to remember that side effects are highly individual and vary by the class and dose of drug you are taking and your individual genetics.

What should you do if you get side effects?

When your doctor first prescribes you a medicine, they may explain what side effects you might experience.

Many side effects, like mild headaches or dizziness, typically improve or disappear after a few weeks as your body gets used to the medicine.

And in some cases, you may experience symptoms because you believe a certain medicine will cause side effects because of something you’ve read or been told before you start taking it.

This is a well-known psychological issue called ‘nocebo effect’.

• Read more research into the nocebo effect with beta blockers

But for some people, it takes some time to get used to a medicine.

If you get side effects your doctor may suggest you try a different dose, medicine or combination to try and help.

If they persist, it may be that you need specialist input to help manage your high blood pressure and your GP may refer you to a specialist.

If you are concerned that your medicine is causing side effects, speak to your doctor or pharmacist for further advice.

Do not stop taking your medication without talking to a doctor first, as your blood pressure could increase to a dangerously high level.

If you are having any problems with your medicine that is not on your patient information leaflet, you can report it to the Medicines and Healthcare product Regulatory Agency Yellow Card scheme.

Tips to help ease side effects

Here are some practical tips to help you manage your symptoms:

• Dizziness – lie down until it passes, move slowly from sitting to standing, and drink plenty of water.
• Headache – use paracetamol sparingly and drink plenty of water, if headaches persist speak to your pharmacist who can recommend pain relief.
• Swollen ankles – wear loose fitting shoes and elevate your legs to help the swelling go down and rest.
• Keep a journal – note down your side effects for the first 2 to 3 weeks on a new medicine as this can help your GP to see patterns, like if dizziness only happens an hour after taking the pill, making it much easier to adjust your treatment plan.
• Take your medicines at the right time - if you take a diuretic (water pill) always take it in the morning because taking it late in the day will mean having to pee during the night, leading to disturbed sleep.
• Take medicine with food – some medicines can cause nausea or an upset stomach so take your pills with or after food to help ease these symptoms.
• Ask for a medicine review – your GP may change your prescription to ease side effects, such as changing the dose, timings or swap you to another blood pressure lowering medicine.

What to read next...