Utilization and Predictors of PPI Co-Prescription in Warfarin- Treated Patients: Opportunities for Clinical Pharmacy Intervention

Abstract

Background: Warfarin is recommended for several diseases, but it may cause bleeding particularly gastrointestinal bleeding. Proton pump inhibitor (PPI) is recommended in five conditions such as history of peptic ulcer disease, co-administration of antiplatelet, NSAIDs, or corticosteroids. There is limited data on PPI prophylaxis in patients with warfarin treatment with these five conditions. Objective: This study aimed to find additional predictors for PPI prophylaxis in patients who received warfarin therapy with any other recommended factors. Methods: This study was a retrospective cohort study conducted on hospital database of Khon Kaen University, Thailand. The inclusion criteria were adult patients who received warfarin therapy with any indications and were indicated for PPI prophylaxis by presence of one of any recommended factors mentioned above. Rates of PPI prophylaxis in the five conditions and clinical factor predictive PPI prescription were analyzed. Results: There were 1,789 patients who required PPI prevention while taking warfarin. The mean age of all patients was 70.45 year with a proportion of male patient of 51.87%. Of those, 611 patients (34.15%) received PPI prevention. According to the recommended factors, the PPI group had higher proportions of patients with age of more than 65 years (80.36% vs 73.60%), uncomplicated peptic ulcer disease (2.95% vs 0.68%), and concomitant corticosteroid (27.66% vs 12.31%) than the non-PPI group significantly. Concomitant antiplatelet and NSAIDs were not significant (p value = 0.665 and 0.458). Several predictors for PPI prophylaxis were identified such as diabetes, ischemic heart disease, treatment with clopidogrel, or internists as a primary physician. Conclusions: PPI prophylaxis in patients treated with warfarin was low at 34.15%. Predictors both positively and negatively of PPI prophylaxis were identified in five categories. Physicians who treat patients with warfarin therapy should be acknowledged on PPI prophylaxis appropriately. Additionally, these findings highlight the need for pharmacy-led interventions, such as clinical audits or risk assessment tools, to ensure appropriate gastroprotection in patients on warfarin.