RISK OF ADMINISTERING CEPHALOSPORIN ANTIBIOTICS TO PATIENTS WITH HISTORIES OF PENICILLIN ALLERGY

Objectives: The purpose of this review was to analyze available releva nt data regarding the safety of administering cephalosporins to penici llin-allergic patients, including the significance of penicillin skin test reactions and any difference related to first, second, or third g eneration cephalosporins. Background: Penicillin and cephalosporins bo th contain a beta-lactam ring. This structural similarity has led to c onsiderable confusion about the cross-allergenicity of these drugs and the risks of allergic reactions from cephalosporins in penicillin-all ergic patients. Methods: Published reports and post-marketing data fro m pharmaceutical corporations provided the basis for this analysis. Re sults: The overall incidence of adverse reactions from cephalosporins ranges from 1% to 10%, with rare anaphylaxis (<0.02%). In patients wit h histories of penicillin allergy the incidence of cephalosporin react ions is minimally, if at all increased. Post-marketing studies of seco nd and third generation cephalosporins showed no increase in allergic reactions in patients with penicillin allergy histories. Penicillin sk in tests do not predict the likelihood of allergic reactions to cephal osporins in patients with histories of penicillin allergy. One reactio n occurred in 98 patients (1%) with positive penicillin skin tests and six reactions occurred in 310 patients (2%) with negative tests. Conc lusions: These data indicate that it is safe to administer cephalospor in antibiotics to penicillin-allergic patients and penicillin skin tes ts do not identify potential reactors.