Should pharmacists play an active role in penicillin skin testing? These practitioners think the move could help reduce antimicrobial resistance

Penicillin allergy is one of the most frequently self-reported drug allergies with an incidence ranging from 10-20%, but research shows only a much smaller percentage is truly allergic.

Meanwhile patients with documented penicillin allergies (either self-reported or clinically confirmed) often receive broader-spectrum antibiotics, a practice associated with increase antimicrobial resistance.

Use of penicillin skin testing to evaluate for true allergies before prescribing broad-spectrum antibiotics has therefore been strongly recommended for decades by major organisations such as the Centers for Disease Control and Prevention.

However practitioners from the NewYork-Presbyterian Brooklyn Methodist Hospital in the US say such testing is not routinely offered in many healthcare settings.

To combat this, clinical pharmacy coordinator Eunah Cheon and infectious disease specialist Dr Harold Horowitz suggest wider adoption of a model wherein pharmacists play an active role in penicillin skin testing.

Standardised penicillin skin testing is a method to assess type I (IgE-mediated) reactions that has been shown to be safe and effective, explain Ms Cheon and Dr Horowitz.

The negative predictive value of this test ranges from 97-99% and systemic adverse reactions are extremely uncommon (<1%).

So far the most common model in the US has been for pharmacists to screen and interview patients with documented penicillin allergies and to refer them to allergists for the test when appropriate.

Allowing pharmacists to conduct the tests themselves could help to bolster the service and consequently reduce the unnecessary use of broader-spectrum antibiotics, they say.

“The pharmacist’s role on patient care teams has expanded greatly in recent years,” the practitioners wrote in the Clinical Infectious Diseases journal this month.

“For instance, it has become fairly common practice for pharmacists to administer immunisations.

“Advancing pharmacist’s roles to provide penicillin skin testing would be a step in the same direction and we suspect an important contribution to patient care.”

However the authors point out there are several challenges to forwarding this idea, including lack of standardised training programs and limited experience with implementation of such services.

They add that “the biggest obstacle is the fact that the scope of practice for pharmacists as defined in [US] state board regulations more often than not does not include penicillin skin testing.”