Underreported Risk of Lisinopril-Induced Angioedema in a Veteran Population

Background: Lisinopril-induced angioedema (LIA) is a rare but serious adverse drug event (ADE) with a published incidence of 0.1% to 0.7%. It is well known that ADEs are widely underreported; however, LIA is one of the most reported ADEs within the Veterans Health Administration (VHA). Objective: To estimate the effect of underreporting on the risk of LIA within VHA. Methods: The reported risk of LIA was calculated from reports submitted to the Veterans Affairs (VA) Adverse Drug Event Reporting System (VA ADERS) and the number of veterans prescribed lisinopril. To estimate underreporting, local chart review identified cases of LIA that were compared to reports submitted. The underreporting rate was then applied to the national reported risk. Results: Locally, 68 reports of LIA were submitted of the 21 262 patients prescribed lisinopril, for a reported risk of 0.32%. Nationwide, 14 289 reports of LIA were submitted of the 3 109 661 patients prescribed lisinopril, for a crude reported risk of 0.46%. Of the 324 patients identified for chart review, 240 patients were diagnosed with LIA, suggesting that at least 71.7% of cases were unreported. When this underreporting rate is extrapolated to the national reported risk, a better estimate of the risk of LIA within VHA could increase to 1.6%. Conclusion and Relevance: When estimating the effect of underreporting, the risk of LIA increases to approximately 1.6% or 1 in 63 patients. Because this ADE may affect more patients than previously understood, providers may wish to take LIA into consideration when prescribing lisinopril.