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ACE (angiotensin-converting enzyme) Inhibitors

ACE inhibitors are usually given to people with high blood pressure, heart failure, or people with a high likelihood of developing coronary artery disease. They may also be given after a heart attack to prevent more complications and to people living with heart failure. They help control your blood pressure to make it easier for the heart to pump. ACE inhibitors may also make you feel less tired and short of breath, reduce the time you spend in the hospital and help you live longer.

ACE inhibitors have been shown to reduce the risk of heart attack, stroke and death in people with a history of coronary artery disease. They have also been shown to reduce the risk of heart attack and death in people with heart failure. Since ACE inhibitors are used to control and prevent conditions of the heart, they are usually prescribed for the long term.

How does it work?
ACE inhibitors reduce the activity of an enzyme (ACE) which helps create a protein called angiotensin II.  Angiotensin II can raise blood pressure by causing your blood vessels to narrow. ACE inhibitors helps lower your blood pressure by decreasing the amount of angiotensin II your body makes. By lowering blood pressure, blood can flow better and your heart doesn’t have to work as hard.

How should I take it?
In order to prevent lightheadedness or dizziness, your doctor may start you with a small dose and increase it gradually. It is important that you keep your doctor appointments and have your blood pressure checked regularly in order to adjust your dose. Captopril is one ACE inhibitor that needs to be taken on an empty stomach. Other ACE inhibitors do not seem to be affected by food. Always talk to your doctor or pharmacist about how and when to take your medication.

What should I avoid while taking this medicine?
You should try to avoid drinking alcohol while taking ACE inhibitors.

What if I am taking other medicines?
Always tell your doctor and pharmacist about any other medication you are taking including prescription, non-prescription, over-the-counter or natural health products (vitamins and minerals, herbal remedies, homeopathic medicines, traditional medicines such as traditional Chinese medicines, probiotics and other products such as amino acids and essential fatty acids).

Some products that may interact with ACE inhibitors include:

  • Non-steroidal anti-inflammatory drugs (NSAIDS) may lessen the effectiveness of the ACE inhibitor.
  • Aluminum or magnesium-containing antacids may decrease the effect of some ACE inhibitors; check with your pharmacist.
  • Potassium supplements may result in increased potassium levels when combined with an ACE inhibitor.
  • Over-the-counter medications for weight loss, colds, cough, hay fever or sinus problems (they may increase blood pressure).

What are some common side effects?
Most people have no problems taking an ACE Inhibitor. However, some people may experience unwanted effects. Always discuss the possible side effects of your medication with your doctor and pharmacist.

Common side effects include: dizziness or lightheadedness, diarrhea, nausea, persistent dry cough, headache, loss of taste or a metallic taste in your mouth (this effect usually only occurs with high doses and goes away after a few months). Tell your doctor and pharmacist of any side effects you experience.

Combination treatments
Most people with high blood pressure need two or more medications to lower their blood pressure. In some cases, two medications can be taken as a single tablet.

Lifestyle changes
Eating a healthy diet that is lower in fat, especially saturated and trans fats, being smoke free, limiting alcohol use, being physically active and reducing stress are also important in lowering the risk of heart disease. Talk to your healthcare practitioner about how you can achieve these lifestyle changes.

For more information
Health Canada provides health and medical information to help Canadians maintain and improve their health. Learn more about Safe Use of MedicinesSafety and Effectiveness of Generic Drugs and Buying Drugs over the Internet.

Drug Product Database provides information about drugs approved for use in Canada.

MedEffect Canada provides safety alerts, public health advisories, warnings and recalls.

Your ministry of health also provides useful health resources in your province or territory. For example, Ontario has a MedsCheck program providing free pharmacist consultations on safety use of drugs. British Columbia has a Senior Healthcare webpage providing information about important health programs.  

Last modified: July 2011
Last reviewed: July 2011