Antibiotic Prescribing for Cellulitis in the Absence of Penicillin-Cephalosporin Cross-Reactivity Alerts: A...

Cephalosporins are often avoided in patients with penicillin adverse drug reaction (ADR) labels. In our institution's electronic medication management system, penicillin and cephalosporin ADR labels do not generate cross-reactivity alerts. Penicillins and cephalosporins are preferred treatments for cellulitis. We aimed to describe penicillin, cephalosporin, and non-penicillin, non-cephalosporin (NPNC) prescribing for inpatients with cellulitis in the presence/absence of penicillin and/or cephalosporin ADR labels. Index cellulitis admissions were included from 2017 to 2024 where at least one penicillin, cephalosporin, or NPNC was administered, and were categorized according to the presence/absence of penicillin and/or cephalosporin ADR labels. Penicillin, cephalosporin, and NPNC prescribing was compared between groups with and without labels using odds ratios (OR) with 95% confidence intervals (CI). Of the 8374 included index admissions, 7567 had no penicillin/cephalosporin labels, 729 had penicillin-only labels, 42 had cephalosporin-only labels, and 36 had both labels. Inpatients with penicillin labels were significantly more likely (OR 13.07; 95% CI, 11.05-15.45) to be prescribed cephalosporins than those without labels. There were no differences in penicillin prescribing between those with cephalosporin labels and those without labels (OR 1.04; 95% CI, 0.44-2.47). Inpatients with penicillin and/or cephalosporin labels were 6 to 52 times more likely to receive NPNC antibiotics than those without labels. The absence of cross-reactivity alerts was associated with increased cephalosporin use for cellulitis in inpatients with penicillin ADR labels, sparing NPNC antibiotics that may be less effective. The removal of cross-reactivity alerts may be effective for increasing cephalosporin prescribing for inpatients with penicillin ADR labels.