Angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs)

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What are ACE inhibitors and ARBs?
Angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) are medicines commonly prescribed for hypertension. These medicines work by relaxing your blood vessels.
Your doctor may also prescribe ACE inhibitors or ARBs if you have:

There are many ACE inhibitors and ARBs available in Australia. The different ACE inhibitors and ARBs have similar effects on your medical condition but have different dosages and potential side effects.
The ARB medicines all have names ending in “sartan” so you might hear them referred to as “sartans”.
How do ACE inhibitors and ARBs work?
ACE is a natural enzyme in your body that produces a substance called angiotensin II. Angiotensin II narrows your blood vessels, causing your blood pressure to rise, making your heart work harder and releasing other hormones that can raise your blood pressure further.
ACE inhibitors work by blocking the actions of ACE. ARBs work by blocking the actions of angiotensin II in your body.
Both these types of medicine can help relax and widen your blood vessels, which lowers your blood pressure and takes strain off your heart and your kidneys. These medicines can also help limit the effects of stress hormones on your heart.
You shouldn’t take ACE inhibitors or ARBs if you:

are pregnant
have a history of allergy to ACE inhibitors or ARBs
took ACE inhibitors or ARBs in the past and they caused problems with your kidney function
have very low blood pressure
have high blood potassium levels (hyperkalaemia)

Before making any changes to your medicines or doses, speak to your doctor or pharmacist.
What types of ACE inhibitors and ARBs might I be prescribed?
ACE inhibitors that you might be prescribed include:

If you have high blood pressure (hypertension), you might be prescribed a combination pill, containing either:

2 medicines: an ACE inhibitor or ARB together with a calcium channel blocker or a diuretic
3 medicines: an ARB, a calcium channel blocker and a diuretic

If you have heart failure, you might be prescribed a combination drug containing valsartan and a drug called sacubitril.
You shouldn’t be prescribed an ACE inhibitor with an ARB. You should only be prescribed one or the other. This is because of an increased risk of acute kidney injury and high potassium levels that are linked to abnormal heart rhythms when both medicines are used together.
What are the side effects of ACE inhibitors and ARBs?
If you’re taking an ACE inhibitor or ARB, common side effects may include:

dizziness or light headedness
dry cough (more common with ACE inhibitors, if you experience a cough on taking an ACE inhibitor your doctor may suggest switching to an ARB)
worsening of your kidney function or increase in your blood potassium level (your doctor may suggest regular monitoring and may change your dose or tell you to stop taking the medicine)
allergic reactions including swelling in your face and mouth, breathing difficulty and rash (more common with ACE inhibitors)

If you or someone else is having trouble breathing, call triple zero (000) and ask for an ambulance.
When should I see my doctor?
It’s important to see your doctor regularly if you’re taking ACE inhibitors or ARBs. Your doctor will monitor your blood pressure, take regular blood tests and may suggest dose changes if necessary.
Sometimes you might be asked to monitor your blood pressure at home, or to have 24-hour ambulatory blood pressure monitoring to check that you’re prescribed the right dose of your ACE inhibitor or ARB.
If you experience side effects that trouble you such as a cough, rash or feeling dizzy, speak to your doctor or pharmacist. If your face begins to swell, or you have difficulty breathing, you should go to the nearest emergency department or call 000.
Are there alternatives to ACE inhibitors or ARBs?
Your doctor may recommend other medicines for hypertension in addition to or instead of ACE inhibitors or ARBs.
You should do your best to eat a healthy, varied diet, exercise regularly and maintain a healthy weight.
A healthy lifestyle reduces your chances of developing high blood pressure, heart and kidney disease and diabetes, and can improve your condition if you have these illnesses.
If you have high blood pressure (hypertension) you should eat a low salt diet.