What to Know About ACE Inhibitors

Angiotensin-converting enzyme (ACE) inhibitors are oral medications that lower blood pressure. They are used to treat a variety of heart-related conditions including high blood pressure, coronary artery disease, and heart failure. They are also used to help control the progression of diabetes and kidney disease.

This article looks at ACE inhibitors, their uses, precautions, and contraindications. It also discusses how to take and store ACE inhibitors, and what some of the side effects might be.

How ACE Inhibitors Are Used

ACE inhibitors were approved for treating hypertension in 1981. Over time, ACE inhibitor use has expanded dramatically to treat cardiovascular disease and related conditions.

Diabetes and heart disease often occur together. High blood pressure is very common in people with diabetes. It can also contribute to the development of a kind of kidney disease called diabetic nephropathy.

Heart problems in people with diabetes tend to lead to longer hospitalizations, longer recovery times, and higher risks of infection. For this reason, healthcare providers usually treat hypertension in concert with diabetes.

ACE inhibitors don’t directly lower blood sugar, but they can contribute to blood sugar control. This is because they increase the body’s sensitivity to insulin. Insulin helps you metabolize glucose (sugar) and move it from the bloodstream into cells. Once in the cells, it acts as a source of energy.

ACE inhibitors have also been shown to have additional benefits for people with diabetes and those at risk for diabetes. These include:

• Delaying the onset of type 2 diabetes
• Lowering the risk of heart attack, stroke, and kidney disease
• Reducing overall mortality
• Decreasing the risk of mortality from cardiovascular conditions

Many ACE inhibitors are available in the United States. Examples include:

• Capoten (captopril)
• Prinivil and Zestril (lisinopril)
• Vasotec (enalapril)
• Lotensin (benazepril)
• Altace (ramipril)
• Accupril (quinapril)
• fosinopril
• Mavik (trandolapril)
• Aceon (perindopril)
• Univasc (moexipril)

“Off-Label” Uses

ACE inhibitors are sometimes used "off-label." This means a healthcare provider may prescribe them to treat a health problem other than the one approved by the FDA. 

For example, ACE inhibitors are sometimes used to help control abnormal heart rhythms, particularly after a heart attack. They may also be used off-label to treat diseases like:

• Rheumatoid arthritis
• Migraines
• Raynaud’s phenomenon
• Bartter syndrome

How ACE Inhibitors Work

ACE inhibitors stop the body from producing a hormone called angiotensin II. Angiotensin II causes narrowing of blood vessels and fluid retention. This can lead to hypertension.

ACE inhibitors help prevent heart failure by reducing blood pressure and fluid retention. They may also prevent and control diabetic nephropathy and help control an eye condition called diabetic retinopathy. They do not slow the heart or directly lower blood sugar. 

Precautions and Contraindications

You should not take ACE inhibitors if:

• You have very low blood pressure (hypotension)
• You have renal artery stenosis, a condition that causes narrowing of the arteries that supply the kidneys with blood
• You have had an allergy or a cough related to ACE inhibitor use
  

If you have significant kidney damage, you will likely need adjusted dosing of ACE inhibitors.

ACE inhibitors can harm a fetus or infant. For this reason, people who are pregnant, trying to conceive, or breastfeeding should not use them. If you do become pregnant while taking an ACE inhibitor, let your healthcare provider know so you can switch to a different medication right away.

How to Take and Store

ACE inhibitor dosing varies depending on other medications you may be taking. Some ACE inhibitors should be taken with food. Always check the directions before taking your first dose.

ACE inhibitors should be stored according to the package instructions. This generally means keeping them in a cool, dry place, like a cupboard or medicine cabinet.

To prevent your blood pressure from dropping too much while you sleep, you should avoid taking an ACE inhibitor before bed. It is a good idea to track your blood pressure levels, then check with your healthcare provider to find the right time to take your medications.

Alcohol is also best avoided while taking an ACE inhibitor. Both lower blood pressure, so drinking may interact in unpredictable and unsafe ways with these medications.

Side Effects

ACE inhibitors are generally very well tolerated. Still, some side effects are possible.

For example, all blood pressure medications carry a risk of low blood pressure (hypotension). Symptoms of low blood pressure include:

• Sweating
• Nausea
• Lightheadedness
• Dizziness and fainting

If you experience low blood pressure, perhaps after standing up too quickly, try lying down for a few minutes. Eat a small, healthy snack and drink a glass of water.

If these symptoms last longer than 15 minutes, seek immediate medical help. In some cases, especially among older people, prolonged lightheadedness can be a sign of a heart attack or stroke. If your symptoms pass but recur often, check with your healthcare provider. You may need to reduce your medication dose.

Rarely, ACE inhibitors can also cause low blood sugar (hypoglycemia). This can happen in people with diabetes who have blood sugar levels that are otherwise well controlled by diet and other antidiabetic medications.

High potassium levels, called hyperkalemia, can also occur in rare cases. Be sure to tell your healthcare provider if you use a salt substitute that is high in potassium, such as Lo Salt.

The most common side effect of ACE inhibitors is a dry or hacking cough. This happens in between 4% and 35% of people who take ACE inhibitors. Many people who experience this side effect end up switching to a different medication.

If you develop a cough while taking an ACE inhibitor, talk to your healthcare provider. There are other medication options, such as angiotensin receptor blockers, that do not cause coughing.

Other side effects may include fatigue and headaches. Some people may also have skin allergic reactions, which can range from mild to severe. Rarely, ACE inhibitors can cause tissue swelling, called angioedema. This risk is higher in females and people of African and Asian descent. 

Make sure to report any side effects to your healthcare provider, even if they seem minor. This is especially important whenever you start taking any new medication. This is because side effects are often avoidable, and may also be signs of a more serious problem. 

Warnings and Interactions

If you have diabetes, it's important to tell your healthcare provider about any medication you are taking. This includes prescription and over-the-counter medications, as well as herbs and supplements.

If you're taking an ACE inhibitor, check with your healthcare provider before you start taking any additional medications or supplements. 

Summary

ACE inhibitors are medications used to treat high blood pressure. They are also used off-label to treat other conditions such as abnormal heart rhythms, rheumatoid arthritis, and migraines.

ACE inhibitors can cause side effects like low blood pressure or a dry, hacking cough. They shouldn't be taken by people with hypotension or certain kidney problems.