A pharmacist-driven deprescribing protocol for negative urine and sexually transmitted infection cultures in the emergency department increases antibiotic-free days

Purpose Emergency department (ED) pharmacists commonly perform positive culture follow-ups that result in optimized antibiotic prescribing. The purpose of this study was to evaluate the potential positive impact on the outcome of antibiotic-free days through an ED pharmacist-driven protocol to contact patients with negative urine cultures and sexually transmitted infection (STI) test results who were discharged with antibiotics.Methods This was a single-center, prospective, observational, pre-post intervention study to determine antibiotic use in patients with negative urine cultures who were discharged from the Loyola Medical University Center ED with antibiotics prescribed. Patients were identified through daily positive culture reports. The primary outcome was days free of antibiotics, defined as the number of calendar days within 28 days after urine culture or STI test collection on which the patient did not receive any antibiotic treatments.Results One hundred ninety-two patients were screened. Sixty-three and twenty-six patients met the inclusion criteria in the pre- and postintervention groups, respectively. The study identified 163/465 (35.1%) antibiotic free days for the preintervention group, compared to 150.5/187 (80.5%) antibiotic-free days for the postintervention group. A majority of the patients did not have urinary tract infection as the chief complaint. The most common urinary and STI symptoms upon ED admission in the pre- and postintervention groups were dysuria (19.2% vs 28.1%) and unusual discharge (30.8% vs 28.6%), respectively.Conclusion This study showed that a pharmacist-driven protocol increased the number of antibiotic-free days for patients prescribed empiric antibiotic therapy and discharged from the ED with subsequent negative urine cultures and STI results. We propose taking a novel approach in discontinuation of antibiotics by implementing an expansion of ED culture programs to include negative cultures that promote antimicrobial stewardship.