Safety of angiotensin-converting enzyme inhibitors in patients with insect venom allergies

OBJECTIVE: To review the literature with respect to the safety of angiotensin-converting enzyme (ACE) inhibitors in patients allergic to insect venom and those undergoing venom immunotherapy (VIT). DATA SOURCES: A MEDLINE search was conducted (1966-March 2006) using the following search terms: bee sting, venom, insect stings, ACE inhibitors, angiotensin II receptor blockers, immunotherapy, and desensitization. The bibliographies of qualifying articles were also searched for relevant references. DATA SYNTHESIS: Several case reports have described severe allergic reactions, including anaphylaxis, in patients taking ACE inhibitors subsequent to being stung or receiving VIT Exacerbation of the allergic response by ACE inhibitors is thought to be related to accumulation of bradykinin and inhibition of the formation of angiotensin II. Similar reactions have not been described with angiotensin-receptor blockers, but are theoretically possible. CONCLUSIONS: ACE inhibitors may exacerbate the response to insect venom, resulting in potentially life-threatening allergic reactions to insect stings or VIT Although this risk is difficult to quantify based only on data from case reports, it seems prudent that patients with documented allergic reactions to insect venom avoid ACE inhibitor therapy, if possible. If, after careful consideration of the risks and benefits, ACE inhibitor therapy is deemed warranted, education regarding measures to minimize exposure to insect stings and training on self-administration of epinephrine should be provided, as with any person with venom allergy. In patients in whom VIT is appropriate, temporary discontinuation of the ACE inhibitor prior to each venom injection may prevent subsequent adverse reactions.