• Posted February 14, 2023

Not Allergic to Penicillin After All? Your Pharmacy May Not Know

When testing determines that a patient who was thought to be allergic to penicillin actually is not, the warning is expected to be removed from their charts and pharmacy records.

But that "de-labeling" is not always happening.

"Penicillin allergy labels are associated with increased health care cost burdens as well as adverse events for patients,"said lead author Dr. Althea Marie Diaz, an allergist at NYU Langone Long Island Hospital in Mineola, N.Y. "Many patients carrying a penicillin allergy label can safely take penicillin, but even after allergy testing we're finding those allergy labels aren't always being removed."

To study this, the researchers identified 78 charts of patients who were de-labeled for penicillin allergy from May 2019 to May 2022.

Any patient who had their penicillin allergy removed from their electronic medical record (EMR) was also provided with a wallet card, according to the study.

Letters were sent to patients' primary care physicians and their pharmacy of choice. The researchers then conducted phone interviews with patients and pharmacies to determine if penicillin had been successfully de-labeled.

The investigators found that 99% of the charts were de-labeled in the EMR system. But 31% of charts still had an active penicillin allergy listed with the pharmacy.

The research team did follow-up interviews with 68 patients. About 97% recalled they had received a negative penicillin allergy result. About 44% said they had taken penicillin since then, while 52% had not. About 4% were still avoiding penicillin despite their negative allergy result.

"We've come a long way when it comes to de-labeling penicillin allergies, but we have a long way to go,"Diaz said in a news release from the American Academy of Allergy, Asthma & Immunology. "We need to continue to examine what barriers are preventing us from completely de-labeling patients who can safely take penicillin and develop strategies to address those barriers."

The findings are scheduled for presentation in San Antonio at a meeting of the American Academy of Allergy, Asthma & Immunology, Feb. 24 to 27. The findings were also published in a February online supplement to The Journal of Allergy and Clinical Immunology.

More information

The U.S. Centers for Disease Control and Prevention has more on penicillin allergy.

SOURCE: American Academy of Allergy, Asthma & Immunology, news release, Feb. 3, 2023