Two epinephrine doses may be needed for anaphylaxis

NEW YORK (Reuters Health) - Some patients who are at risk for a severe allergic reaction caused by a food allergy will require two doses of epinephrine, rather than just one, according to the findings of a new study. Researchers therefore recommend that allergic patients carry two doses of epinephrine.

Dr. Eyal Oren of Massachusetts General Hospital in Boston and colleagues reviewed the records of patients seen at the hospital's emergency department for food-induced anaphylaxis, a severe, life-threatening allergic reaction that requires immediate treatment. It is characterized by swelling of the airways that can block breathing and may also include a dramatic drop in blood pressure.

The investigators reviewed medical records of 39 patients who sought treatment for severe allergic reactions to food at the hospital's emergency department over the course of 1 year. Nineteen had anaphylaxis.

Twelve of the patients were given at least one dose of epinephrine, while three, or 16 percent, received two doses. The patients given two doses were allergic to peanuts or tree nuts, and two of the three experienced a drop in blood pressure.

"These results suggest that the use of multiple doses of epinephrine in the management of food-induced anaphylaxis is not a rare occurrence," they write in the current issue of the Annals of Allergy, Asthma and Immunology.

Recent recommendations have called for allergic individuals to carry two doses of epinephrine rather than just one. These findings suggest that those with food allergies will also benefit from doing so, Oren and his team note.

Given the small size of the study and the fact that patients who were not seen in the emergency room for treatment weren't included, more research is needed to confirm the findings, the researchers say.

Nevertheless, they conclude, the findings suggest that patients "at risk for food-induced anaphylaxis should carry at least two doses of self-injectable epinephrine."

SOURCE: Annals of Allergy, Asthma and Immunology, November 2007.