病人服用華法林（Warfarin）。護理師應優先監測哪項檢驗數值以評估藥物療效？

華法林主要影響外源性凝血路徑，臨床上以凝血酶原時間（PT）及其標準化比值（INR）作為監測指標。通常目標 INR 範圍在 2.0-3.0 之間，需依據適應症調整。若數值過低表示抗凝血不足，過高則有出血風險，需定期抽血調整劑量。

Warfarin primarily affects the extrinsic coagulation pathway, and prothrombin time (PT) with its standardized ratio (INR) is used clinically as the monitoring parameter. The target INR range is typically 2.0-3.0, adjusted based on the indication. A value that is too low indicates inadequate anticoagulation, while a value that is too high carries a bleeding risk; periodic blood sampling is therefore required for dose titration.

台美兩地皆以 INR 為標準，但美國許多診所設有抗凝血劑門診由藥師主導劑量調整，台灣則多由醫師決定。