746Tolerability of Cephalosporins and Carbapenems in Patients with Reported Penicillin Allergies in a Real World Setting

Background. Practitioners have historically avoided cephalosporins and carbapenems in penicillin allergic patients. Despite recent literature suggesting a lower crosssensitivity than originally reported; practitioners continue to avoid cephalosporins and carbapenems in this patient population. The purpose of this study is to evaluate the tolerability of cephalosporins and carbapenems in patients with reported penicillin allergies in a real world setting. Methods. A retrospective study was performed using de-identified information from patient medical records. Patients were excluded if a cephalosporin or carbapenem allergy was reported prior to receiving the antibiotic, an unspecified beta-lactam allergy was listed, or a medication to treat an allergic reaction (steroids, diphenhydramine, or IM epinephrine), were received two hours prior to receiving the antibiotic. Cross-reactions were determined if the antibiotic was discontinued and either received a medication to treat an allergic reaction or an allergy was added to their patient profile. Results. Five hundred patients were included (n = 480 Cephalosporins, n= 20 Carbapenems) and 20 met the reaction criteria resulting in a prevalence of 4% cross-sensitivity for all included patients, and 4.2% (n = 20) for cephalosporins and 0% (n = 0) for carbapenems. Reported penicillin allergy severity and the rate of reaction were found to be statistically significant (p value 0.035). When the variables gender, antibiotic received, and age were held at fixed values, andthe prior penicillin allergy reaction was listed as severe the odds ratio for another reaction was 6.6 (p-value 0.032, 95% CI 1.17-37.66) and 5.9 for mild (p-value 0.021, 95% CI 1.3126.95). Conclusion. Despite the limitations of a de-identified, retrospective study the results show a low cross-reactivity prevalence rate and the limited reactions that occur were mild in nature. Giving a cephalosporin or carbapenem to patients with reported penicillin allergies appears to be well tolerated in a real world setting. Disclosures. All authors: No reported disclosures.