ACE inhibitor drugs okay with venom therapy

By David Douglas

NEW YORK (Reuters Health) - Use of a class of blood pressure-lowering drugs called angiotensin-converting enzyme (ACE) inhibitors does not appear to be contraindicated in people with severe allergies to bee, wasp or hornet stings who are being treated with venom from these stinging insects, Texas-based researchers report.

The treatment, known as venom immunotherapy, involves exposure to tiny amounts of venom that activates a small allergic reaction. The idea is to stimulate the immune system to build up a tolerance to the venom; over time, the treatment can prevent allergic reactions in most people.

In a report published in the medical literature this month, Dr. Kevin M. White and Dr. Ronald W. England of Wilford Hall Medical Center, San Antonio, note that there have been several case reports of severe system-wide reactions in venom allergic and other patients taking ACE inhibitors who have been stung or exposed to venom immunotherapy.

Their current findings are "preliminary evidence that patients who receive life-saving venom immunotherapy can safely continue or start ACE inhibitors," White told Reuters Health.

White and England identified 79 people who had venom immunotherapy, 17 of whom were taking ACE inhibitors to control blood pressure.

None of the patients taking an ACE inhibitor experienced an adverse systemic reaction while having venom immunotherapy, they report. On the other hand, 13 (21 percent) of the patients who were not taking an ACE inhibitor did have a systemic reaction.

There does not appear to be an association between ACE inhibitors and systemic reactions, the researchers conclude.

"ACE inhibitors are a cornerstone of treating cardiovascular and renal disease and should not be withheld without good evidence," White commented.

SOURCE: Annals of Allergy, Asthma and Immunology, October 2008.