The effectiveness of Pharmacist-driven Medication optimization: A Retrospective study on Warfarin and Digoxin

Background: Warfarin and digoxin are essential for managing cardiovascular conditions but carry risks of adverse drug reactions (ADRs) due to their narrow therapeutic indices, particularly in patients on concurrent therapy, with polypharmacy, or chronic kidney disease (CKD). The role of clinical pharmacists in optimizing these therapies remains underexplored. Objective: To evaluate the impact of pharmacist-driven interventions on therapeutic success, ADRs, medication adherence, and hospital readmissions in patients on warfarin, digoxin, or both. Methods: This retrospective cohort study analyzed 270 patients at Farah Medical Complex, Amman, Jordan, from January to December 2023. Outcomes included therapeutic success, time to therapeutic target and stabilization, ADR incidence, adherence, and hospital readmissions. Data were analyzed using Kaplan-Meier survival analysis, Cox proportional hazards models, and multivariate logistic regression. Results: Of 270 patients (162 warfarin-only, 80 digoxin-only, 28 concurrent), pharmacists delivered 277 interventions (1.03/patient), achieving therapeutic success in 83.7% (226/270). Warfarin-only patients reached therapeutic INR in 88.2% within 8.2 ± 11 days, digoxin-only in 86.3% within 11 ± 13 days, and concurrent therapy in 85.7% (INR) and 71.4% (digoxin) within 9.1 ± 9 and 14 ± 11 days, stabilizing at 26–33 days. Frequent interventions (HR=1.61–1.92, p