Abstract
Background. Patients with reported β-lactam antibiotic allergies (BLAs) are more likely to receive broad-spectrum antibiotics and experience adverse outcomes. Data describing antibiotic allergies among solid organ transplant (SOT) and hematopoietic cell transplant (HCT) recipients are limited. Methods. We reviewed records of adult SOT or allogeneic HCT recipients from 1 January 2013 to 31 December 2017 to characterize reported antibiotic allergies at time of transplantation. Inpatient antibiotic use was examined for 100 days posttransplant. Incidence rate ratios (IRRs) comparing antibiotic use in BLA and non-BLA groups were calculated using multivariable negative binomial models for 2 metrics: Days of therapy (DOT) per 1000 inpatient days and percentage of antibiotic exposure-days. Results. Among 2153 SOT (65%) and HCT (35%) recipients, 634 (29%) reported any antibiotic allergy and 347 (16%) reported BLAs. Inpatient antibiotics were administered to 2020 (94%) patients during the first 100 days posttransplantation; average antibiotic exposure was 41% of inpatient-days (interquartile range, 16.7%-62.5%). BLA patients had significantly higher DOT for vancomycin (IRR, 1.4 [95% confidence interval {CI}, 1.2-1.7]; P < .001), clindamycin (IRR, 7.6 [95% CI, 2.2-32.4]; P = .001), and aztreonam in HCT (IRR, 9.7 [95% CI, 3.3-35.0]; P < .001), and fluoroquinolones in SOT (IRR, 2.9 [95% CI, 2.1-4.0]; P < .001); these findings were consistent when using percentage of antibiotic exposure-days. Conclusions. Transplant recipients are frequently exposed to antibiotics and have a high prevalence of reported antibiotic allergies. Reported BLA was associated with greater use of β-lactam antibiotic alternatives. Pretransplant antibiotic allergy evaluation may optimize antibiotic use in this population. © The Author(s) 2019.