藥物警訊（藥師週刊第1758期）

Pradaxa (dabigatran etexilate mesylate): Drug Safety Communication - Safety Review of Post-Market Reports of Serious Bleeding Events

AUDIENCE: Cardiology, Pharmacy, Hematology

ISSUE: FDA is evaluating post-marketing reports of serious bleeding events in patients taking Pradaxa (dabigatran etexilate mesylate). Bleeding that may lead to serious or even fatal outcomes is a well-recognized complication of all anticoagulant therapies. The Pradaxa drug label contains a warning about significant and sometimes fatal bleeds. In a large clinical trial (18,000 patients) comparing Pradaxa and warfarin, major bleeding events occurred at similar rates with the two drugs.

FDA is working to determine whether the reports of bleeding in patients taking Pradaxa are occurring more commonly than would be expected, based on observations in the large clinical trial that supported the approval of Pradaxa.

BACKGROUND: Pradaxa is a blood thinning (anticoagulant) medication used to reduce the risk of stroke in patients with non-valvular atrial fibrillation (AF), the most common type of heart rhythm abnormality.

RECOMMENDATION: At this time, FDA continues to believe that Pradaxa provides an important health benefit when used as directed and recommends that healthcare professionals who prescribe Pradaxa follow the recommendations in the approved drug label.

Patients with AF should not stop taking Pradaxa without talking to their healthcare professional. Stopping use of blood thinning medications can increase their risk of stroke. Strokes can lead to permanent disability and death.

FDA will communicate any new information on the risk of bleeding and Pradaxa when it becomes available.

FDA正在評估Pradaxa (dabigatran etexilate mesylate)上市後嚴重出血的不良事件，而出血可能導致嚴重或致死的結果是所有抗凝血療法廣為人知的併發症；Pradaxa的仿單中已註明可能有重 大且致死性出血的警語；但在一個18,000人的大型臨床試驗中，比較分別使用Pradaxa與warfarin，發現二組發生嚴重出血的機率相似。

FDA正在評估這些上市後的嚴重出血不良事件，相較於先前臨床試驗的觀察，是否比預期中的還多。

Pradaxa是一種抗凝血劑，用於降低常見的非瓣膜性心房纖維顫動（non-vavular atrial fibrillation）病人罹患中風的風險。

此時，FDA認為依據藥品仿單資訊使用dabigatran仍具有其重要之臨床效益，並建議醫護人員處方Pradaxa時，需依照藥品仿單建議使用，同時 也建議AF的病人不可擅自停藥，因為停止使用抗凝血劑可能會增加中風的風險，甚至會永久傷殘或死亡。FDA將會持續更新相關資訊。

相關訊息與連結請參考FDA網址：
http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm282820.htm

[Posted 12/07/2011]

資料來源：美國FDA之藥物安全警訊
資料提供：台大醫院藥劑部