Carbapenem–valproic acid derivative drug-drug interactions: Evaluation of a pharmacist-facing OurPractice Advisory

PURPOSE: The purpose of this quality improvement evaluation was to describe implementation and postimplementation experience with a pharmacist-facing OurPractice Advisory (OPA) within the Epic electronic health record designed to identify concurrent carbapenem antibiotic and valproic acid (VPA) derivative therapy. SUMMARY: A pharmacist-facing OPA was developed to identify selected clinical scenarios involving carbapenem antibiotics and VPA derivatives, including scenarios involving active inpatient medication orders and prior-to-admission medication list entries. A retrospective review was conducted for hospitalized patients with OPA activations over a 10-month period. The OPA appeared for 30 hospitalized patients. The most common activation scenario was a carbapenem ordered in the presence of an already verified inpatient VPA derivative order, occurring in 19 patients (63.3%). The most common VPA derivative indication was mood stabilization in 12 patients (40%), followed by a seizure-related indication in 9 patients (30%). The median (IQR) time to pharmacist order decision was 21.5 (5.25-51.25) minutes. Formal infectious diseases consultation and neurology consultation occurred in 23 (76.7%) and 10 (33.3%) patients, respectively. Antibiotic therapy was switched from a carbapenem to a different antibiotic in 14 cases (46.7%), VPA derivative therapy was held, discontinued, or not verified in 7 cases (23.3%), and both agents were continued without change in 8 cases (26.7%). CONCLUSION: Implementation of a pharmacist-facing OPA provided a structured process for identifying and documenting selected carbapenem-VPA derivative drug-drug interaction scenarios during pharmacist order verification. Postimplementation review identified opportunities for refinement, including reduction of repetitive activations, clarification of acknowledgment options, and consideration of earlier prescriber-facing clinical decision support.