SARS-CoV-2 and Warfarin Dose Interaction in Patients with Non-Valvular Atrial Fibrillation
Poramate Rungrattanawilai, MD1, Phanthaphan Sureeyatanaphat, MD1, Pattama Sahasoonthorn, PharmD2, Warisara Pangprasert, PharmD2, Teetouch Ananwattanasuk, MD1, Padoemwut Teerawongsakul, MD, MSc1
Affiliation : 1Department of Internal Medicine, Faculty of Medicine Vajira Hospital, Navamindradhiraj University, Bangkok, Thailand, 2Department of Pharmacy, Vajira Hospital, Bangkok, Thailand
Objective: Warfarin is commonly used to prevent cardioembolic illness in patients with atrial fibrillation (AF). However, warfarin has a narrow therapeutic range and requires continuous monitoring for safety and effectiveness. Numerous factors, including infection and inflammation, can affect the dose of warfarin. SARS-CoV-2 infection involves multiple inflammatory pathways leading to hyperinflammation. This study explored warfarin dosing in patients hospitalized with SARS-CoV-2 infection and other factors that affect warfarin dosing.
Materials and Methods: The authors performed a retrospective descriptive study among adult patients with AF receiving warfarin treatment 180 days before and after being infected with SARS-CoV-2 who were admitted to Vajira Hospital between January 2020 and June 2022. The primary outcome was a difference in average warfarin daily dose (WDD) between pre-infection and inpatient SARS-CoV-2 infection. Secondary outcomes were a difference in the average WDD between pre- and postinfection, a difference in time to therapeutic range (TTR) between pre- and postinfection, and factors affecting warfarin dosage after infection.
Results: Twenty patients were included in the present study. The average inpatient WDD was significantly lower than the average WDD before SARS-CoV-2 infection (2.10±1.11 mg vs. 3.01±1.34 mg, p<0.001), and the mean reduction in WDD was 28.3%. The mean average WDD after infection was significantly lower than the mean average WDD before infection (2.62±1.19 mg vs. 3.01±1.34 mg, p=0.002), and the mean reduction in WDD was 11.5%. There was no difference between mean pre- and postinfection TTR (46.7 vs. 44.9, p=0.794). Consumption of green chiretta was associated with a significantly higher warfarin dosage following SARS-CoV-2 infection (p=0.046).
Conclusion: SARS-CoV-2 infection may interact with the warfarin level. Adults hospitalized with SARS-CoV-2 infection and following postdischarge follow-up had considerably lower average WDDs.
Received 14 May 2024 | Revised 25 August 2024 | Accepted 10 September 2024
Keywords : Warfarin; Vitamin K antagonist; SARS-CoV-2; COVID-19
