Deborah Brauser

March 01, 2010

Dr. James Li

March 1, 2010 (New Orleans, Louisiana) — Patients with a history of anaphylaxis to penicillin yet who have negative results on penicillin skin testing can safely take preoperative cephalosporins, according to a retrospective study presented here at the American Academy of Allergy, Asthma and Immunology 2010 Annual Meeting.

In fact, "over 98.8% of this patient population in our study was able to tolerate cephalosporins," lead author James T. Li, MD, PhD, professor of medicine and chair of the allergy and immunology division at the Mayo Clinic College of Medicine in Rochester, Minnesota, told meeting attendees.

"We were able to successfully decrease vancomycin use, which is beneficial to the hospital and it's a benefit to the patient because they can receive a first-line antimicrobial agent rather than a second-line agent," said Dr. Li in an interview with Medscape Allergy and Clinical Immunology. "I would like to see this practice generalized to other hospitals."

Assessing Preoperative Cephalosporins

Approximately 1300 patients with a history of penicillin allergy are evaluated at Mayo each year. "When patients have this allergy and they're ready to go into surgery, many won't receive cephalosporins because of the concern of cross-reactivity. So vancomycin is the second-line medication of choice," explained Dr. Li.

He noted that although the literature cites a 10% incidence rate of self-reported penicillin allergies, about 90% of these patients undergoing skin-prick tests will show a negative result.

Although past studies have shown that patients with a negative penicillin allergy skin test can take cephalosporins safely, the objective of this study was to assess whether this was still true in patients who also had a history of anaphylaxis to penicillin, "because these are most of the patients who end up on vancomycin."

Dr. Li and his team examined data on 15,298 patients from their penicillin allergy database from January 1999 to April 2009 and identified 193 with a self-reported history of anaphylaxis to penicillin. The investigators then reviewed their charts for penicillin skin test results, whether preoperative cephalosporins were given, and if there were any subsequent adverse drug reactions.

"The skin testing procedure used was standard at Mayo, using benzylpenicilloyl polylysine, penicillin G potassium, and penicilloate," reported Dr. Li.

Safe Use of Cephalosporin in 79 of 80 Patients

Results at the end of the study showed that 178 of those with a penicillin anaphylaxic history underwent the skin tests, with 12 (6.7%) showing positive reactivity and 156 (87.6%) showing negative allergic reactions. The remaining 10 had equivocal results.

Of the 156 patients with no reactions, 80 received a cephalosporin antibiotic preoperatively. Only 1 (1.25%) of these had a possible adverse drug reaction, which was reported as muscle and joint pain after a plastic surgery procedure.

"This was actually unlikely to be an allergic reaction and, frankly, we don't really believe it had anything to do with the cephalosporin use," said Dr. Li. "I think that 1 patient was a nonissue."

"The main finding of the study was that patients with a history of anaphylaxis to penicillin can receive preoperative cephalosporin safely if their skin tests are negative," he summarized.

During the Q&A session after the presentation, he said that their were several reasons they wanted to try to reduce the administration of vancomycin at their institution, including the fairly high incidence of adverse drug reactions (such as red skin erythema, rashes, and sometimes kidney disorders), the fact that its increased use drives the emergence of vancomycin-resistant organisms, and the fact that it delays surgery.

"Part of the reason our project ended up being successful is that we were able to partner with our surgeons and anesthesia people," said Dr. Li. "A patient going for surgery with a history of penicillin allergy and subsequent use of vancomycin delays their start time. What drove the success of this enterprise was that we wanted to keep the operating rooms running on time."

Penicillin Skin Testing a Useful Tool

"This study is a big deal because you can't really get [vancomycin] administered anymore without prior approval from infectious disease consultants, who are responding to the overuse of antibiotics," said session comoderator Kim E. Mudd, RN, MSN, CCRP, clinical research coordinator at Johns Hopkins University Medical Center in Baltimore, Maryland.

"There's a protocol for using vancomycin that can be lengthy. So for [the investigators] to go back and partner with the [operating room] surgeons is absolutely brilliant. It made this whole study very doable and it's a very useful tool because we don't want to be hanging vancomycin on patients if we don't have to," said Ms. Mudd, who was not involved with the study.

"Everybody faces this situation, every institution. There's an overidentification of penicillin allergy and then you layer that onto the need to control infection in the hospital. I think this could be a standard-changing approach. They obviously need to expand the research, but I think a lot of people are going to end up doing this," concluded Ms Mudd.

Dr. Li and Ms. Mudd have disclosed no relevant financial relationships.

American Academy of Allergy, Asthma and Immunology (AAAAI) 2010 Annual Meeting: Abstract 250. Presented February 27, 2010.


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