Abstract P307: Effect of Bradykinin Receptor Antagonism on ACE Associated Angioedema

Abstract

The B2 receptor antagonist icatibant is approved for treatment of attacks of hereditary angioedema. Icatibant has been reported to decrease time-to-resolution of ACE inhibitor-associated angioedema in one study of European patients. Patients with ACE inhibitor-associated angioedema (defined as swelling of lips, tongue, pharynx or face during ACE inhibitor use and no swelling in the absence of ACE inhibitor use) were randomized within six hours of presentation to SQ icatibant 30 mg or placebo at zero and six hours later. Patients assessed severity of swelling using a visual analog scale serially following study drug administration or until discharge. Thirty-one patients were randomized to and received treatment, with 13 receiving icatibant and 18 receiving placebo. One patient randomized to icatibant did not complete the visual analog scale and was excluded. Two-thirds of patients were African American and two-thirds were women. Time-to-resolution of symptoms was similar in placebo and icatibant treatment groups [p=0.19 for the primary symptom (Figure) and p>0.16 for individual symptoms of face, lip, tongue, or eyelid swelling]. Frequency of administration of H1 and H2 blockers, corticosteroids, and epinephrine was similar in the two treatment groups. Lip swelling was more severe in blacks (p=0.03), while tongue swelling was more severe in whites (0.02). White patients were significantly more likely to receive epinephrine (p=0.01). Time-to-resolution of symptoms was similar in blacks and whites. This study does not support the clinical efficacy of administration of a B 2 receptor blocker in black or white American patients with ACE inhibitor-associated angioedema.