The Penicillin Allergy Delabeling Program: A Multicenter Whole-of-Hospital Health Services Intervention and Comparative Effectiveness Study

Background Penicillin allergies are associated with inferior patient and antimicrobial stewardship outcomes. We implemented a whole-of-hospital program to assess the efficacy of inpatient delabeling for low-risk penicillin allergies in hospitalized inpatients. Methods Patients ≥ 18 years of age with a low-risk penicillin allergy were offered a single-dose oral penicillin challenge or direct label removal based on history (direct delabeling). The primary endpoint was the proportion of patients delabeled. Key secondary endpoints were antibiotic utilization pre- (index admission) and post-delabeling (index admission and 90 days). Results Between 21 January 2019 and 31 August 2019, we assessed 1791 patients reporting 2315 antibiotic allergies, 1225 with a penicillin allergy. Three hundred fifty-five patients were delabeled: 161 by direct delabeling and 194 via oral penicillin challenge. Ninety-seven percent (194/200) of patients were negative upon oral penicillin challenge. In the delabeled patients, we observed an increase in narrow-spectrum penicillin usage (adjusted odds ratio [OR], 10.51 [95% confidence interval {CI}, 5.39–20.48]), improved appropriate antibiotic prescribing (adjusted OR, 2.13 [95% CI, 1.45–3.13]), and a reduction in restricted antibiotic usage (adjusted OR, 0.38 [95% CI, .27–.54]). In the propensity score analysis, there was an increase in narrow-spectrum penicillins (OR, 10.89 [95% CI, 5.09–23.31]) and β-lactam/β-lactamase inhibitors (OR, 6.68 [95% CI, 3.94–11.35]) and a reduction in restricted antibiotic use (OR, 0.52 [95% CI, .36–.74]) and inappropriate prescriptions (relative risk ratio, 0.43 [95% CI, .26–.72]) in the delabeled group compared with the group who retained their allergy label. Conclusions This health services program using a combination of direct delabeling and oral penicillin challenge resulted in significant impacts on the use of preferred antibiotics and appropriate prescribing.

The Oral Pheneticillin Absorption Test: An Accurate Method to Identify Patients with Inadequate Oral Pheneticillin Absorption

Severe streptococcal infections are commonly treated with intravenous followed by oral penicillin (pheneticillin) therapy. However, switching from iv to oral therapy is complicated by the variability in oral pheneticillin absorption. We employed an Oral Absorption Test (OAT) for pheneticillin to identify patients in whom oral pheneticillin absorption is poor. Out of 84 patients 30 patients (36%) were identified as insufficient absorbers. Treatment failure due to pheneticillin malabsorption can be avoided by performing an OAT, and these patients should be treated by another antibiotic, which is known to be absorbed well.

The Safety and Efficacy of an Oral Penicillin Challenge Program in Cancer Patients: A Multicenter Pilot Study

Antibiotic allergies are reported by up to 1 in 4 cancer patients, almost 50% of which are considered low risk and precede the cancer diagnosis. We demonstrate the successful and safe implementation of a pilot oral penicillin challenge program for cancer patients with low-risk penicillin allergies, increasing the use of penicillin and narrow-spectrum beta-lactams post-testing.