What is Angioedema?

The Full Story

ACE-inhibitors are medications that are commonly used for the treatment of high blood pressure and heart failure, and to prevent kidney disease in patients with diabetes. Their names end with “pril” and examples include lisinopril, enalapril, and ramipril. They work by blocking the ACE enzyme in the body, which is the enzyme that produces angiotensin II, a hormone that that causes blood vessels to constrict. Constriction of blood vessels leads to high blood pressure and kidney problems and worsens heart failure. 

ACE-inhibitors are very effective at reducing blood pressure, preventing kidney failure, and decreasing death from heart failure. For this reason, they are commonly prescribed medications. At the same time, they are generally well tolerated with mild adverse effects, such as a dry cough and dizziness.  

There is one serious adverse effect associated with ACE-inhibitor use, called angioedema. Angioedema is swelling of the tissues primarily around the mouth, lips, and eyes. In more serious cases, the area in the throat around the vocal cords may swell and block the person’s ability to breathe. Angioedema happens in less than 1% of patients taking ACE-inhibitors, but when it does occur, it can be life-threatening because the swelling may close off the airway and make breathing difficult or impossible. Angioedema occurs most frequently within the first week of treatment with an ACE-inhibitor, but in one third of cases, it occurs after months or years of treatment. Angioedema from ACE-inhibitors is five times more common in African Americans than whites. 

Angioedema can occur from causes other than ACE-inhibitors, including other medications, allergic reactions, vasculitis (inflammation of the blood vessels), and hereditary diseases. Angioedema can also involve other areas of the skin and the intestinal tract, but this is more common with causes of angioedema not related to medication. One other important class of drugs that cause angioedema, but less commonly than ACE-inhibitors, is angiotensin receptor blockers (ARBs). These drugs are similar to ACE-inhibitors and often end with “artan”. Common examples include losartan and valsartan. 

Angioedema from ACE-inhibitors is not an allergic reaction; it is caused by a chemical called bradykinin that accumulates in the body when taking an ACE-inhibitor. Sometimes medicines used to treat allergic reactions such as steroids or antihistamines can also be used to treat angioedema, but they are not always effective. The most important part of treatment for angioedema from ACE-inhibitors is stopping the medication and monitoring the swelling. This is best done in an emergency department or hospital because if the swelling progresses, it can affect the airway and breathing. Although rare, in these cases a breathing tube may be needed. 

It is important to remember if someone has angioedema from an ACE-inhibitor, they should never take that medication again. Other ACE-inhibitors can cause the same reaction and they should be avoided as well. Always let your doctor know if you or a loved one has had angioedema after using ACE-inhibitors, so that a safe substitute can be prescribed. Always tell your healthcare team that you have had angioedema from an ACE-inhibitor so they know to avoid these medications. 

If someone on an ACE-inhibitor is having swelling around the face, contact your doctor and seek medical care immediately. If the person is having trouble breathing, call 911 for immediate assistance. Get an immediate personalized recommendation online or call Poison Control at 1-800-222-1222. Both options are free, confidential, and available 24 hours a day.

Maryann Amirshahi, PharmD, MD, MPH, PhD
Medical Toxicologist