HomeClinical TopicsCardio-PulmonaryWhen ACE inhibitors cause angioedema

When ACE inhibitors cause angioedema


Chances are, you’ve administered angiotensin-converting enzyme (ACE) inhibitors, such as captopril, enalapril, or lisinopril, to many patients. Worldwide, more than 40 million people take these drugs—most of them to treat heart failure or hypertension, especially after myocardial infarction. These drugs also are given for coronary artery disease, diabetes mellitus, chronic renal disease, or recurrent stroke.

The most common adverse reactions to ACE inhibitors are cough, hypotension, and dizziness. Hyperkalemia and functional renal failure arise less often. An even rarer but potentially much more serious adverse reaction is angioedema. This localized skin swelling results from release of inflammatory mediators, which leads to increased capillary permeability and fluid extravasation into the tissue. (See A greater risk for African-Americans.)

A greater risk for African-Americans

Overall, angioedema occurs in only about 0.1% to 0.2% of patients receiving angiotension-converting enzyme (ACE) inhibitors. But the incidence is higher among African-Americans. A study of more than 12,000 patients taking enalapril found black patients were about three times more likely to develop angioedema within 6 months of starting therapy (1.62% versus .55% of white patients). In other research, the mean age of patients who experienced angioedema from ACE inhibitors or angiotensin receptor blockers (ARBs) was 60, with a higher incidence in women (60%) and African-Americans (69%).

Angioedema can develop over minutes to hours, and typically resolves in 1 to 2 days. Although usually self-limiting, it can be life-threatening—especially if it goes unrecognized and untreated.
ACE inhibitor-related angioedema usually arises shortly after drug therapy begins, but in some cases it’s delayed for months or even years. Occasionally, it doesn’t begin until several weeks after the patient has stopped taking the drug.


Signs and symptoms of ACE inhibitor-related angioedema can range from mild and clinically insignificant to severe and life-threatening. Edema may be so mild that patients may not even report it to a healthcare provider. Rarely, pruritus accompanies angioedema; some patients have associated erythema. Symptoms may resolve spontaneously, only to recur at irregular intervals. Unlike edema linked to heart failure or renal disease, angioedema common takes an asymmetric pattern and isn’t gravity dependent.

In a multicenter study of emergency-department patients with the condition, the most common presenting signs and symptoms were shortness of breath, lip and tongue swelling, and laryngeal edema. In more severe cases, patients had swelling of the lips, tongue, posterior pharynx, and eyes. Up to 20% of patients experience dyspnea, dysphagia, dysphonia, and stridor, which may progress rapidly to life-threatening airway obstruction unless treated.

If you suspect angioedema, obtain a thorough medical history (including medication history). Be sure to document a description of the edema and its pattern, noting its first appearance and associated signs and symptoms.

Ruling out other causes

Other possible causes of angioedema include allergies to food, drugs, latex, and insect stings or bites. However, pruritus or urticaria usually accompany angioedema from these causes. The physician also must rule out idiopathic angioedema and C1 esterase inhibitor deficiency—a hereditary or acquired condition that disrupts the pro-inflammatory response, causing recurrent angioedema.


In most cases, stopping the ACE inhibitor is the only treatment needed. However, be sure to evaluate the patient for airway compromise, and be prepared to intervene appropriately. A patient with significant airway compromise that threatens ventilation should be hospitalized for careful observation, with an intubation tray kept near the bedside. Be aware that nasotracheal intubation is recommended, as nonpitting edema can make oral intubation difficult or even impossible.

For acute treatment of ACE inhibitor-related angioedema, antihistamines are the standard therapy. However, these drugs may be ineffective because inflammatory mediators other than histamine appear to be the basis for angioedema caused by ACE inhibitors. I.V. corticosteroids and subcutaneous epinephrine are reserved for more severe episodes. Be aware, though, that corticosteroids have unproven value, and epinephrine works in a nonspecific way to temporarily constrict leaky blood vessels. Recently, fresh-frozen plasma has been shown to substantially improve ACE inhibitor-related angioedema.

Patient education

For patients who need ACE inhibitors despite a high risk for angioedema—for instance, those who’ve had previous idiopathic angioedema—provide an epinephrine kit, as ordered, and give instructions on how to use it. Teach them to discontinue the ACE inhibitor if angioedema occurs and to contact a healthcare provider or seek emergency care immediately.

Inform patients who’ve experienced ACE inhibitor-related angioedema that they are allergic to this drug class. Advise them to mention this allergy to all healthcare providers so they won’t receive ACE inhibitors in the future. Teach first-time ACE inhibitor users how to recognize adverse drug reactions; instruct them to notify a healthcare provider promptly if angioedema or another serious adverse drug reaction occurs.

Maureen P. Flattery is a heart transplant coordinator at Pauley Heart Center at Virginia Commonwealth University Health System in Richmond.


Austen KF. Diseases of immediate type hypersensitity. In Harrison’s Principles of Internal Medicine. 16th ed. McGraw Hill, New York, 2004.

Banerji A, et al. Multicenter study of patients with angiotensin-converting enzyme inhibitor-induced angioedema who present to the emergency department. Ann Allergy Asthma Immunol. 2008;100(4):327-332.

2010 Heart Failure Society of America Comprehensive Heart Failure Practice Guidelines Website. Available at: http://www.hfsa.org/heart-failure-guidelines-2/. Accessed March 9, 2011.

Kostis JB, et al. Incidence and characteristics of angioedema associated with enalapril. Arch Intern Med. 2005;165:1637-1642.

Malder B, Regalado J, Greenberger PA. Investigation of angioedema associated with the use of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers. Ann Allergy Asthma Immunol. 2007;98:57-65.

Sarkar P, Nicholson G, Hall G. Brief review: Angiotensin converting enzyme inhibitors and angioedema: anesthetic implications. Can J Anesth 2006; 53: 994-1003.

Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure 2003. http://www.nhlbi.nih.gov/guidelines/hypertension/index.htm. Accessed December 1, 2006.

Sica DA, Black HR. Angioedema in heart failure: Occurrence with ACE inhibitors and safety of angiotensin receptor blocker therapy. CHF 2002; 8: 334-41, 45.

Weber MA, Messerli FH. Angiotensin-converting enzyme inhibitors and angioedema: estimating the risk. Hypertension. 2008;51:1465.


  1. My S/O had a severe allergic reaction to Ace inhibitors in October 2018. ER had to shove a breathing tube down his throat and he was put into a coma for five days on a fentinal drip and benedryl. It was terrifying and he has never been the same since. He was in very closely observed by robot doctors from Stanford in Palo Alto. He now has developed extreme heart problems, and also received merca in his nose from hospital he was in ICU for 5 days, and an infection from catheder and later lead into pnemonia, and 3 more ER trips in 2019.

  2. 30 year old white female here. Been hospitalized 3 times for angioedema in my small bowel and we think it is from the lisinopril I was on for 2 years. Switched to Novasc in January, but just recently had a flare up, even though I’m not on the ACE inhibitor anymore.

  3. I am a 69 year old retired R.N. and was taking lisinopril since April of 2018 for hypertension. Went to the ER a couple of months ago with bilateral +3 pitting edema of both feet, and no cause was ever found. About two weeks ago, my lower right lip swelled and I thought possibly I had experience some type of bug bite in my sleep, and it resolved within a day. Three nights ago, I suddenly felt that I possibly had a canker sore on the right side of my tongue, but then began to feel my tongue swell. After about an hour I went to ER, and they gave me IV solumedrol, benadryl, and pepcid. It began to resolve after approx 2 hours and I convinced them to release me. I have discontinued the drug, but evidently have to now live in fear that this could occur again at any time and might not have such a favorable outcome if and when it does. Angry, frightened and traumatized doesn’t cover it. Horrible experience to wonder if at any moment you might be intubated and possibly die if unsuccessful!

  4. I have been taking Lisinopril for 2 months I am 52 yr old black female had to go to ER for Angioedema just got switched to Losartan I am really worried I am going to have more attacks I have been taken off the meds due to the fact that I have severe environmental allergies. I just read the Harvard article on blood pressure meds that can trigger allergic reactions this is very scary!!!!

  5. I’m a white female age 71 and I had Angioedema of the tongue. They were talking ICU and tracheotomy! Fortunately a dose of Benadryl, Solu-Medrol and a new drug works in an hour or two.

  6. My uvula swells after taking a 20 mg lisinipril every time I also take a nsaid….even a baby aspirin. Hate to go back to larger doses of amlodipine calcium channel blocker because of ankle swelling….Losartan worked fine until I needed a higher dose, then the skin rashes came on…… really frustrating dilemma!

  7. I’m 52. I was taking Benazapril and developed angioadema every 3-4 months finally taken off it and given Losartan and developed more side effects. I’ m done. I’m looking for herbal treatments now.

  8. This happened to me a few weeks ago and I was completely shocked. I’m black American. I’d never had an allergic reaction in all my life. I got very stressed out and my lip started swelling. I was upset for another reason and hoped it was just swelling due to crying. It would be odd but it was the only thing I could think of. In the afternoon, I realized it wasn’t going down and went to my medical center’s acute care unit. I got diagnosed and immediately taken off the ACE inhibitor I was taking

  9. I am a 58 yr old female. I have been to ER 6 times since Dec 2011. Sewlling of lips, face, tongue, midsection, botom of my feet. Aweful Alwys the same treatment syeroids, benadryl, pepsid and most recently an anti anxiety med (I freak out when I feel it coming on). I do not take high blood prssre meds. I havebeen tested for food and environmental aleries and try to avoid things I amallergic to. ost recentlt i started afterwhat seeme to b spider bites then suddenly progressed and escalated.

  10. My daughter is 9 years old and has been on enalapril for four years. Her tongue swelled….cause is enalapril. Scary, scary,scary!

  11. I am a 5o y.o. RN who has been taking Enalapril 10mg po OD for 4 years. 48 hours ago I was in an ambulance rushing to the ER with a moderate case of ACE induced-angioedema. Primary involvement was face (asymmetrical), throat, tongue, lips, and neck. There was no stridor present but swallowing was extremely difficult. Following IV treatment with steroids, benadyl and pepcid, the edema subsided and I was d/c’d home on all 3 meds for 7 days. It is a very real and terrifying adverse event.


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