Impact of Antimicrobial Stewardship Interventions on Peripartum Antibiotic Prescribing in Patients with Penicillin Allergy.

BACKGROUND: Beta-lactam antibiotics (e.g. penicillins, cephalosporins, carbapenems) are preferred for Group B Streptococcus prophylaxis, intraamniotic infection, and cesarean surgical site infection prophylaxis. Non-beta-lactam alternatives are associated with inferior efficacy and contribute to higher rates of surgical site infection rates and longer lengths of stay. The majority of patients who report a penicillin allergy can tolerate penicillins without any adverse reaction. There are low rates of cross-reactivity between penicillins and other beta-lactams, including cephalosporins and carbapenems. Efforts to evaluate penicillin allergy and promote the use of beta-lactams are needed.

OBJECTIVE: To evaluate whether an antimicrobial stewardship intervention improved the use of first-line antibiotics for peripartum indications in patients with a reported penicillin allergy, following updates to institutional guidelines.

STUDY DESIGN: This was a retrospective study of adult patients presenting for vaginal or cesarean delivery at two hospitals within a healthcare system. Patients received at least 1 dose of antibiotics for a peripartum indication between May 1 2018 - October 31 2018 (pre-intervention) and May 1 2020 - October 31 2020 (post-intervention). The stewardship intervention bundle, which was implemented between March 2019 and April 2020, included updates to institutional antibiotic guidelines, reclassification of severe penicillin allergy, development of obstetric prophylaxis and treatment order sets, promotion of allergy referral services, and establishment of a physician champion. The primary outcome was the composite rates of patients with reported penicillin allergy who received a preferred antibiotic for a peripartum indication. Secondary measures included maternal and neonatal outcomes.

RESULTS: A total of 192 patients with a history of documented penicillin allergy were evaluated (96 patients in the pre-intervention group and 96 patients in the post-intervention group). Hives were the most commonly reported index symptom in both groups [40/96 (41.7%) vs 39/96 (40.6%), P=0.883]. Following stewardship interventions, there was a significant increase in the rate of preferred antibiotic use [33/96 (34.3%) vs 81/96 (84.3%), P<0.001]. The effect was greatest in patients with non-severe allergy [14/76 (18.4%) vs 68/82 (82.9%), P<0.001]. There were no differences in the rates of postpartum endometritis, 30-day readmission, 90-day surgical site infection, or neonatal early-onset sepsis between the pre- and post-intervention groups. One patient in the post-intervention group experienced itching and another patient developed a rash, both which resolved with medical management.

CONCLUSION: A comprehensive antibiotic stewardship intervention was associated with a 50% increase in the use of preferred antibiotics for peripartum indications in patients with penicillin allergy. Allergic reactions with first-line beta-lactams were minimal and manageable.