What are ACE inhibitors and ARBs?

Angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) are medicines commonly used to treat hypertension (high blood pressure). These medicines work by relaxing your blood vessels.

Your doctor may also prescribe an ACE inhibitors or ARB if you have:

• heart failure
• chronic kidney disease
• diabetes with proteinuria (too much protein in your urine)
• had a heart attack (myocardial infarction)

There are many ACE inhibitors and ARBs available in Australia.

The different ACE inhibitors and ARBs have similar effects on your:

• heart
• kidneys
• blood circulation

Your doctor will choose the best medicine for you. Your doctor will think about how they could help with your condition and about 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 makes your blood vessels become narrower, which causes your blood pressure to rise.

When your blood pressure goes up, your heart needs to work harder. Angiotensin II works with other hormones to raise your blood pressure further.

ACE inhibitors work by blocking the actions of ACE in your body. 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. This helps lower 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 or trying to conceive
• have a history of allergy to ACE inhibitors or ARBs
• took ACE inhibitors or ARBs in the past and had problems with your kidney function
• have very low blood pressure
• have high blood potassium levels (hyperkalaemia)

Speak to your doctor or pharmacist before making any changes to your medicines or doses.

What types of ACE inhibitors and ARBs might I be prescribed?

You might be prescribed one of these ACE inhibitors:

• captopril
• enalapril
• fosinopril
• lisinopril
• perindopril
• quinapril
• ramipril
• trandolapril

You might be prescribed one of these ARBs or 'sartans':

• candesartan
• irbesartan
• losartan
• olmesartan
• telmisartan
• valsartan

If you have hypertension (high blood pressure), you might need a combination medicine. These can contain either an:

• ACE inhibitor AND a calcium channel blocker OR a diuretic
• ARB AND a calcium channel blocker OR a diuretic
• ARB AND a calcium channel blocker AND a diuretic

If you have heart failure, you might be prescribed a combination medicine containing valsartan and sacubitril.

Your doctor shouldn't prescribe an ACE inhibitor with an ARB.

You should only take one or the other. This is because using both medicines together increases your chance of:

• acute kidney injury
• high potassium levels

This can lead to abnormal heart rhythms.

What are the side effects of ACE inhibitors and ARBs?

If you're taking an ACE inhibitor or ARB, the more common side effects include:

• dizziness or light headedness
• increase in the amount of potassium in your blood
• muscle aches and pains
• low blood pressure
• dry cough — more common with ACE inhibitors
• worsening of your kidney function
• allergic reactions — this could be swelling in your face and mouth, breathing difficulty or a rash

If you get a cough while taking an ACE inhibitor your doctor may suggest switching to an ARB.

Your doctor may start you on a low dose at first to lower the chance of side effects. Your doctor will give you instructions on how to slowly increase the dose.

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
• will organise regular blood tests
• may suggest dose changes if needed

Your doctor may ask you to monitor your blood pressure at home. You may need to have ambulatory blood pressure monitoring for 24-hours.

Doing these checks helps to make sure you are on the right dose. If your blood pressure is well controlled it will help to prevent other heart and kidney problems.

Speak to your doctor or pharmacist if you have side effects that trouble you such as:

• a cough
• rash
• feeling dizzy

If your face begins to swell, or you have difficulty breathing, you should go to the nearest emergency department or call triple zero (000).

Are there any alternatives to ACE inhibitors or ARBs?

Your doctor may recommend other medicines for hypertension. They may prescribe other medicines in addition to or instead of ACE inhibitors or ARBs.

You should do your best to:

• eat a healthy, varied diet
• exercise regularly
• maintain a healthy weight

A healthy lifestyle lowers your chance of developing:

• high blood pressure
• heart
• kidney disease
• diabetes

A balanced diet and regular exercise can improve your health if you have these conditions.

If you have high blood pressure your doctor or dietitian might suggest a low salt diet.

If you have sleep apnoea, see your doctor for treatment. Obstructive sleep apnoea can increase your chance of high blood pressure.

Resources and support

For more information and support, try these resources:

• Heart Foundation — blood pressure and your heart.
• National Stroke Foundation — blood pressure and stroke.
• Watch the Heart Foundation's video series on living well with heart failure, or download the booklet.

Do you prefer to listen in a language other than English? The Heart Foundation's video series on living well with heart failure is available in a number of languages.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with you 24 hours a day, 7 days a week.