ACE-inhibitor–related angioedema

Abstract

Otolaryngologists are called upon frequently to care for patients with potentially life-threatening angioedema. This condition usually is associated with angiotensin-converting enzyme (ACE) inhibitors. ACE inhibitors are among the most commonly prescribed medications worldwide because they are indicated in the management of hypertension, congestive heart failure, myocardial infarction, diabetic nephropathy, and chronic kidney disease.1,2 Angioedema is a potentially life-threatening adverse effect of ACE inhibitors, with a reported incidence of 0.1 to 6%.2-8 ACE-inhibitor-related angioedema is asymmetric, nonpitting, non tender edema that can appear anywhere in the body but commonly affects the head and neck area.' Otolaryngologists should be familiar with this drug class and its potential complications. ACE-inhibitor-related angioedema is not a true allergy but is considered an adverse class effect secondary to the mechanism of action. 2,4,s-1O The proposed pathophysiologic mechanism is the accumulation of bradykinin secondary to the inhibition of ACE.2,4,S However, this cannot explain how ACE-inhibitor-related angioedema can occur anytime from hours to deft ient h dth di ti 3411-13 cades a er a patient as starte e me lca IOn. ' , About a quarter of patients with ACE-inhibitor-related angioedema present within 1 week of starting the medication." On the other end of the spectrum, approximately half present after having been on the medication for at least a year," This may be explained by the fact that in the setting of ACE inhibition, aminopeptidase P (APP) and dipeptidyl peptidase 4 (DPP4) become responsible for breaking down the vasoactive peptides bradykinin and substance P, respectively." Factors adversely affecting these enzymes may trigger angioedema. 14 Female gender, African-American descent, and tobacco use are risk factors for the development of ACEinhibitor-related angioedema.3.4.6,7,14 Certain atopic diseases, such as seasonal allergies and asthma, may also be risk factors.Y'":" On the other hand, diabetes mellitus is possibly associated with a decreased risk because diabetic patients appear to have increased DPP4 activity to aid in the breakdown of substance p' ,14,IS Currently, no laboratory test exists to confirm the