ACE inhibitors and angiotensin II receptor blockers
- Madeeha Waheed, Pharmaceutical Policy Manager at Bupa
Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) are medicines that widen your blood vessels thus lowering your blood pressure. They can treat high blood pressure, and heart and kidney problems.
Uses of ACE inhibitors and ARBs
Your doctor may recommend you take ACE inhibitor drugs or an ARB medicine to lower your blood pressure if you have:
- high blood pressure (hypertension)
- heart failure or have had a heart attack
- diabetes, and there are signs of problems with your kidneys
- kidney disease
These medicines aren’t suitable for everyone, so let your doctor know if you have any other health conditions or take other medicines. If you’re trying for a baby or are breastfeeding, let your doctor know because they’ll need to take this into consideration.
It’s your choice whether to take a medicine or not. Discuss your options with your doctor and ask them about the pros and cons of any medicines they suggest.
How ACE inhibitors and ARBs work
ACE inhibitors and ARBs lower your blood pressure and make it easier for your heart to pump blood around your body.
They do this by acting on one of the systems your body has to control your blood pressure. If your blood pressure drops too low, your body will produce a chemical called angiotensin I. An enzyme called angiotensin-converting enzyme (ACE) converts (changes) this into angiotensin II. Angiotensin II narrows your blood vessels and triggers the release of a hormone that makes your body hold on to water. The extra volume of fluid in your bloodstream and the narrowing of your blood vessels make your blood pressure rise again.
Here’s how ACE inhibitors and ARBs work on this system.
- ACE inhibitors block the action of angiotensin-converting enzyme so that angiotensin I isn't converted to angiotensin II.
- ARBs block the action of angiotensin II. You may also see these medicines called angiotensin II receptor antagonists.
If you have kidney disease, ACE inhibitors and ARBs can help your kidneys work better for longer, as well as lower your blood pressure.
Types of ACE inhibitor and ARB
There are lots of different ACE inhibitors. Examples include:
- enalapril (for example, Innovace)
- ramipril (for example, Tritace)
- lisinopril (for example, Zestril)
There are also different ARBs, which include:
- azilsartan (for example, Edarbi)
- candesartan (for example, Amias)
- losartan (for example, Cozaar-Comp)
They work all as well as each other, and ARBs usually have fewer side-effects.
Your doctor will normally decide which is best for you after they consider a number of things including:
- what health condition you have
- if you have any other health problems
Your doctor will usually prescribe you an ACE inhibitor first. If you get the side-effect of a persistent cough, your doctor may offer you an ARB instead. Ask your doctor for more information about what the best medicine is for you.
Taking ACE inhibitors and ARBs
You’ll usually need to take ACE inhibitors or ARBs long-term and have regular check-ups with your doctor. Your doctor will ask you to have a blood test before you start these medicines. They’ll test you again a week or two after you first take the medicine or if they increase your dose.
After this, your doctor will test you every year. These tests are to check that:
- your kidneys are healthy
- your blood pressure is responding well to your medicine
You take most ACE inhibitors or ARBs as tablets or capsules, usually once a day. When you have your first dose, your doctor may advise that it’s best to take it at night. If everything is well and you don’t get bad side-effects, you can take the tablets every morning. Your doctor may start you on a low dose, then increase this gradually over a few weeks or months to reach the most effective dose.
The patient information leaflet that comes with your medicine will tell you more about how to take your tablets. With some tablets it’s important not to crush or chew them, just swallow them whole with a drink of water. If you have any questions or concerns about how to take your medicine, ask a pharmacist.
Interactions of ACE inhibitors and ARBs
ACE inhibitors and ARBs can interact with other medicines to cause unwanted effects. For instance, if you take some medicines together with ACE inhibitors or ARBs, you may get very low blood pressure (hypotension) or very high potassium levels in your blood.
Check with your doctor or pharmacist before you take any other medicines or supplements at the same time as ACE inhibitors or ARBs.
Side-effects of ACE inhibitors and ARBs
Like all medicines, ACE inhibitors and ARBs can cause side-effects for some people. Possible side-effects of ACE inhibitors and ARBs include:
- low blood pressure, which may make you feel dizzy
- a persistent dry cough if you take ACE inhibitors (you don’t usually get this side-effect with ARBs)
- headaches
- tummy (abdominal) discomfort, diarrhoea, constipation, feeling sick or vomiting
Your kidneys may not work as well as they did before you took ACE inhibitors and ARBs.
We haven’t included all the possible side-effects here. The patient information leaflet for your medicine will have more information about side-effects and how common they are. ARBs usually have milder side-effects than ACE inhibitors.
If you get these or other side-effects with ACE inhibitors or ARBs, contact your doctor. They may reduce the dose of your medicine or change to another medicine.
Medicines checklist
Bupa's medicines checklist (PDF, 0.8MB), helps you understand what to check for before taking a medicine.
Both ACE inhibitors and angiotensin II receptor blockers (ARBs) act on a system in the body that controls your blood pressure. The difference between them is they act on the system in different ways. They can also cause different side-effects – ARBs usually cause fewer side-effects than ACE inhibitors.
For more information, see our section on how ACE inhibitors and ARBs work, and our section on side-effects of ACE inhibitors and ARBs.
No, ARBs and ACE inhibitors usually can’t be used together. It won’t give any added benefit in helping to improve your high blood pressure and it can cause problems with your kidneys., Your doctor won’t usually prescribe you both. However, sometimes it’s necessary to take both, particularly if you have heart failure.
There are lots of different ACE inhibitors and ARBs. Examples of ACE inhibitors include ramipril (for example, Tritace), and lisinopril (for example, Zestril). Examples of ARBs include azilsartan (for example, Edarbi) and losartan (for example, Cozaar-Comp).
For more information, see our section on types of ACE inhibitors and ARBs.
Some people cannot take ACE inhibitors or ARBs. You can’t take them if you’re trying for a baby or you are pregnant, for example. And if you’re breastfeeding, they may potentially harm your baby, although sometimes it’s necessary to take the risk. Let your doctor know if you have any other health conditions or take other medicines.
For more information, see our section on uses of ACE inhibitors and ARBs.
Let your doctor know if you have any other health conditions or take other medicines in case there are any reasons why you can’t take the medicines (contraindications). ACE inhibitors and ARBs can interact with other medicines to cause unwanted effects. For example, if you take some types of medicine together with ACE inhibitors or ARBs, it can cause very low blood pressure or very high potassium levels in your blood.
For more information, see our section on interactions of ACE inhibitors and ARBs.
High blood pressure (hypertension)
Coronary heart disease
Type 1 diabetes
Type 2 diabetes
Heart attack
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- Herman LL, Padala SA, Ahmed I, et al. Angiotensin-converting enzyme inhibitors (ACEI). StatPearls Publishing. www.ncbi.nlm.nih.gov, last updated 31 July 2023
- Hill RD, Vaidya PN. Angiotensin II receptor blockers (ARB). StatPearls Publishing. www.ncbi.nlm.nih.gov, last updated 27 March 2023
- Drugs affecting the renin–angiotensin system. NICE British National Formulary. bnf.nice.org.uk, last updated 31 January 2024
- Hypertension. NICE Clinical Knowledge Summaries. cks.nice.org.uk, last revised December 2023
- Renin–angiotensin system physiology. Encyclopaedia Britannica. www.britannica.com, accessed 9 February 2024
- Chronic kidney disease. BMJ Best Practice. bestpractice.bmj.com, last reviewed 9 January 2024
- Enalapril maleate. NICE British National Formulary. bnf.nice.org.uk, last updated 31 January 2024
- Ramipril. NICE British National Formulary. bnf.nice.org.uk, last updated 31 January 2024
- Lisinopril. NICE British National Formulary. bnf.nice.org.uk, last updated 31 January 2024
- Azilsartan medoxomil. NICE British National Formulary. bnf.nice.org.uk, last updated 31 January 2024
- Candesartan cilexetil. NICE British National Formulary. bnf.nice.org.uk, last updated 31 January 2024
- Losartan with hydrochlorothiazide. NICE British National Formulary. bnf.nice.org.uk, last updated 31 January 2024
- Ramipril 10mg tablets. emc. www.medicines.org.uk, last updated 10 June 2021
- Visseren FLJ, Mach F, Smulders YM, et al. 2021 ESC guidelines on cardiovascular disease prevention in clinical practice: Developed by the Task Force for cardiovascular disease prevention in clinical practice with representatives of the European Society of Cardiology and 12 medical societies with the special contribution of the European Association of Preventive Cardiology (EAPC). Eur Heart J 2021; 42(34):3227–337. doi: doi.org/10.1093/eurheartj/ehab484
- Williams B, Mancia G, Spiering W, et al. 2018 ESC/ESH guidelines for the management of arterial hypertension: the Task Force for the management of arterial hypertension of the European Society of Cardiology (ESC) and the European Society of Hypertension (ESH). Eur Heart J 2018; 39(33):3021–104. doi: doi.org/10.1093/eurheartj/ehy339
- Rachael Mayfield-Blake, Freelance Health Editor
