Treatments
You may be having planned or emergency treatment. We explain what to expect, how it will help and what will happen afterwards.
About calcium channel blockers
What are calcium channel blockers?
Calcium channel blockers, or CCBs, are medicines that help your blood vessels to widen and relax. This helps lower your blood pressure and increases the amount of blood flowing to your heart.
Some calcium channel blockers also help slow down your heart rate.
You may be given a calcium channel blocker if you have:
You may also be given other medicines to take for your condition. For example, if you have high blood pressure you may also take an ACE inhibitor.
Most calcium channel blockers are not suitable for people with heart failure. Talk to your doctor about other medicines you can take.
How do calcium channel blockers work?
Calcium channel blockers reduce the amount of calcium entering the cells of your heart and blood vessel walls.
Calcium causes the walls of your blood vessels to contract and tighten, making your blood vessels narrower.
By reducing the amount of calcium, your blood vessel walls relax and become wider. This helps blood flow easier which reduces your blood pressure and helps to prevent angina.
There are different types of calcium-channel blockers. Some work more on your heart’s electrical system which can help slow down your heart rate and are used to treat certain abnormal heart rhythms (arrythmias).
Types of calcium channel blockers
What are the different types of calcium channel blockers?
There are two main types of calcium channel blockers.
- Dihydropyridines – help relax and widen your blood vessels which can help lower your blood pressure and prevent angina. Examples include amlodipine, felodipine, lercanidipine and nifedipine.
- Rate-limiting – help relax and widen your blood vessels, but they can also help slow down and regulate your heart rate. Examples include diltiazem and verapamil.
Find out more about these medicines on the NHS website.
Side effects
What are the side effects of calcium channel blockers?
All medicines have potential side effects, but most people will not experience side effects.
Side effects from this medicine may include:
- headaches
- swollen ankles
- feeling hot and going red in the face (flushing)
- pounding or fluttering in your chest (palpitations)
- tummy (stomach) ache
- feeling sick or being sick
- not being able to go to the toilet (constipation)
- low blood pressure
- feeling dizzy
- feeling sleepy or very tired.
Different medicines will have different side effects. If you’ve started taking calcium channel blockers recently it’s worth bearing in mind that side effects with any new medicine often improve over time or even disappear.
When should I get help?
Talk to your doctor if you’re having side effects. They can help you manage them or look at other options with you.
It’s important not to stop taking your medicine without speaking to a healthcare professional first.
How and when to take them
How do I take this medicine?
Most people will take a calcium channel blocker once a day. Try and take it at the same time every day.
Your doctor will give you more information about the type of calcium channel blocker they’re giving you and how often you should take it.
If you forget to take your medicine and:
- It's only a short time after your usual dose, take it as soon as you remember. Then take your next dose at the usual time.
- It’s nearly time for your next dose, do not take the one you missed. Wait and take your next dose at the usual time.
How long do I take it for?
Most people with high blood pressure will need to take medicines to lower their blood pressure long-term.
Your blood pressure will be checked regularly to make sure it’s under control. If your blood pressure is not under control, your doctor may recommend increasing the dose of your medicine or trying an alternative or additional medicine.
It’s important not to stop taking your medicine without speaking to a healthcare professional first.
Things to avoid if you’re taking calcium channel blockers
It’s important to check with your doctor or pharmacist before taking any other medicine while you’re taking calcium channel blockers.
There are certain foods and medicines you may need to limit or avoid if you’re taking a calcium channel blocker. This is because they can stop your medicine from working properly.
This includes:
- grapefruit, including grapefruit juice
- St John’s wort.
Get help with calcium channel blockers
- Our cardiac nurses can help answer your questions on calcium channel blockers. Call, email or live chat with them on our Heart Helpline.
- Check if you can get free prescriptions or help paying for your prescriptions.
- Talk to other people with high blood pressure and get support in our online community.
You can trust our health information
We've followed an eight-step process to make sure this content is reliable, accurate and trustworthy.
Learn how we make our health content.
Understanding high blood pressure
This booklet can help you and your loved ones understand what high blood pressure is and how to make healthier changes to look after your heart health.
Your blood pressure chart and diary
If you want to measure your blood pressure at home, this blood pressure chart can help you understand what your reading means.