Researchers presented their findings on hypersensitivity caused by antibiotics as well as the best ways pharmacists can test for it.
In 2 posters presented at the 2024 American Pharmacists Association Annual Meeting and Exposition, researchers addressed a slew of antibiotics that caused hypersensitivity and discussed their findings on penicillin allergy skin testing (PST).
“Hypersensitivity reactions occur when the body produces inappropriate immunologic or inflammatory responses to a medication, resulting in symptoms such as rash, anaphylaxis, or serum sickness,” wrote Edwards et al.1
In the first poster, researchers at the University of South Carolina College of Pharmacy tested for hypersensitivity in 72 different antibiotics using the FDA Adverse Event Reporting System (FAERS).1
In the second poster, researchers from Health First Holmes Regional Medical Center in Melbourne, Florida, used PST and the by mouth amoxicillin challenge to determine the best measures for de-labeling patients with a penicillin allergy.2
“The FAERS Public Dashboard is a highly interactive web-based tool that will allow for the querying of FAERS data in a user-friendly fashion. The intention of this tool is to expand access of FAERS data to the general public to search for information related to human adverse events reported to the FDA by the pharmaceutical industry, health care providers, and consumers,” wrote the FDA.3
The FAERS internet database holds every drug reported to the FDA for hypersensitive reactions. Researchers considered over 16 million FDA reports as well as more than 144,000 reports of hypersensitivity.1
During evaluation, 72 different antibiotics were considered and 39 of them had a significant association with hypersensitivity.Among the top reported antibiotics were trimethoprim-sulfamethoxazole (2,550 reports), amoxicillin (1,483), and ciprofloxacin (1,327).1
“These events impact drug selection and encourage a patient-specific approach in prescribing to minimize harm. Of the adverse drug events associated with antibiotics, hypersensitivity reactions are very concerning,” wrote Edwards et al.
Finding several adverse reactions in antibiotics reported in the FAERS database, researchers encourage patients to be proactive about the drugs they choose and to use online resources open to the public, such as FAERS.
When recruiting participants for the study, researchers included adults with a history of penicillin allergies experienced over 10 years ago. Therefore, those with a PST or penicillin reaction in the past 10 years were not included.
Participants (197 outpatients) of the Linn et al study were first given PST during the study period. If the patient passed the PST, they were then given the amoxicillin challenge.2 The challenge, otherwise known as the amoxicillin oral provocation challenge, is a way of treating patients with amoxicillin to further test for an allergic reaction from penicillin.4
“Oral provocation challenge presents a safe and accessible opportunity for primary care providers to address erroneous allergy labels to penicillin and related drugs within the primary care office setting,” wrote Gateman et al.4
Of 197 outpatients, 185 (93.91%) were de-labeled from their penicillin allergy. Eleven of the 12 patients who weren’t de-labeled experienced minor itching and the 12th patient experienced a delayed reaction.2
“This study supports the pharmacist as the provider in de-labeling penicillin allergies and improving patient health outcomes. Furthermore, given the availability of having a dedicated pharmacist, providers could refer multiple patients and expect a reasonable turnaround time to complete testing, including same day testing,” concluded the authors.2
With pharmacists testing for hypersensitivity, a load is taken off primary care providers, expanding responsibilities for pharmacists and their practices. And with pharmacists’ expert knowledge on prescription drugs like penicillin, in the future, adverse reactions can be solely treated in a pharmacy setting.
