Pradaxa is an anticoagulant that acts by inhibiting thrombin, an enzyme in the blood that is involved in blood clotting. The safety and efficacy of dabigatran were studied in a clinical trial comparing dabigatran with the anticoagulant warfarin.
The RE-LY study compared dabigatran at 110mg twice daily and 150mg twice daily against warfarin. Patients who took the higher dosage showed a 34% falloff in stroke risk compared with those on warfarin (p<0.001) over a median of two years.
The approval makes dabigatran available to a broad spectrum of patients, with the 150mg bid dose approved for all patients except for a small subset with severe renal impairment (creatinine clearance 15–30 mL/min) where the approved dose is 75mg bid.
As with other approved anti-clotting drugs, bleeding, including life-threatening and fatal bleeding was among the most common adverse reactions reported by patients treated with dabigatran. Gastrointestinal symptoms, including dyspepsia, stomach pain, nausea, heartburn, and bloating also were reported.
Stuart Connolly, co-principal investigator of RE-LY, Division of Cardiology at McMaster University, Hamilton, Canada, said, “Warfarin has been the standard therapy for stroke prevention in AF for many years. However, it is a very difficult treatment to use because of its interaction with various drugs, food types and the need for continuous monitoring to ensure that the drug is at the right therapeutic level. Anticoagulant monitoring is particularly burdensome and it is often difficult to maintain therapeutic range with warfarin, which puts patients at a higher risk of stroke or major haemorrhage. The approval of dabigatran etexilate provides for the first time an effective, flexible and convenient treatment option in the USA, which will be especially important for the large group of patients who currently do not take any treatment because they cannot tolerate or refuse to take warfarin, or are not adequately controlled under current treatment.”