ACE inhibitors for high blood pressure

Angiotensin-converting enzyme (ACE) inhibitors block an enzyme needed to form a substance that narrows blood vessels. As a result, blood vessels relax and widen, making it easier for blood to flow through the vessels, which reduces blood pressure. These medicines also increase the release of water and sodium to the urine, which lowers blood pressure as well.

ACE inhibitors can be used alone or in combination with a diuretic or other agents.

These medicines are used alone for high blood pressure or are added to a diuretic if a diuretic by itself doesn't work.

• ACE inhibitors are a good choice for people who have had a heart attack because the medicine may help the heart work better.
• ACE inhibitors are a good choice for people with diabetes because they do not affect blood sugar levels and may help protect the kidneys.
• ACE inhibitors may be a good choice for people with asthma or disorders of the electrical system of the heart that would be made worse by other blood pressure medicines such as beta-blockers.
• ACE inhibitors may also help to prevent stroke.¹

Who should not take ACE inhibitors

These drugs should not be taken by women who are pregnant or may become pregnant.

People with advanced kidney failure may require regular blood tests to make sure these medicines do not reduce kidney function or raise potassium levels.

ACE inhibitors can reduce blood pressure in people with all types of high blood pressure. They also help people who have heart failure to live longer, and they slow the development of kidney failure in people with diabetes.

Side effects of ACE inhibitors may include:

• Dry cough.
• Rash or itching.
• Allergylike symptoms.
• Allergic reaction with generalized swelling (angioedema) or, in rare cases, swelling of the upper airway.
• Excess potassium in the body (hyperkalemia), especially in people with kidney failure.

ACE inhibitors may interact with anti-inflammatory medicines, antacids, potassium supplements, certain diuretics, and lithium.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

Usually, ACE inhibitors cause very few side effects. The most common side effect is an irritating dry cough.

It is important to take high blood pressure medicines daily as prescribed. Because high blood pressure often has no symptoms, it is easy to forget to take the pills.

In people who have high blood pressure and heart failure, ACE inhibitors may be a good first choice. Medicines in this class may help protect against kidney damage in people who have diabetes (diabetic nephropathy).

But if you already have severe kidney failure caused by diabetic nephropathy, ACE inhibitors must be used carefully. A low dose is tried first. Potassium levels and kidney function are watched closely as the dose increases.

Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.

Citations

1. PROGRESS Collaborative Group (2001). Randomised trial of a perindopril-based blood pressure-lowering regimen among 6,105 individuals with previous stroke or transient ischaemic attack. Lancet, 358(9287): 1033–1040.