Warfarin is the most commonly prescribed oral anticoagulant in Indonesia. However, the time in the therapeutic range (TTR) remains low across different countries worldwide. This study aimed to analyze the challenges associated with achieving optimal warfarin control. The analysis consisted of two distinct stages. The first stage was a prospective observational study that aimed to analyze anticoagulation control, dosing consistency, INR monitoring compliance, medication adherence, and knowledge of warfarin. Meanwhile, in the second stage, focus group discussion was used to propose strategies for overcoming the challenges. The result showed that the average TTR was 49.4 ± 32.1, where only 37.5% of patients had values ≥ 65%. 

The average dosing consistency obtained was 62.33 ± 32.42%. The majority of patients with supratherapeutic INR values required a 1-month monitoring interval after dose adjustment. Further analysis indicated that only 43.8% of patients were classified as adherent and 39.5% had good knowledge of warfarin, suggesting the level of medication adherence and knowledge was not optimal. Approximately 14.6% of patients received other drugs that potentially interacted with warfarin, causing fluctuations in INR. In conclusion, this study found several challenges associated with achieving optimal warfarin control including barriers to dosing consistency, INR monitoring, medication adherence, and knowledge of warfarin, as well as drug interactions. The proposed solution is a holistic approach combining multifaceted strategies to address each barrier.

Wenny Putri Nilamsari, Indri Yuliani Hamdani, Budi Suprapti, Mochamad Yusuf Alsagaff, Mohammad Yogiarto, and Suharjono

Department of Pharmacy Practice, Faculty of Pharmacy, Universitas Airlangga

Department of Pharmacy, Universitas Airlangga Teaching Hospital, Surabaya 

Department of Cardiology and Vascular, Universitas Airlangga Teaching Hospital, Surabaya 

Department of Cardiology and Vascular, Faculty of Medicine Universitas Airlangga