Pearl: estimating renal function in patients on dabigatran (Pradaxa)
October 18, 2013, 6:24 pm
I was reminded of an key point about dabigatran (Pradaxa) while reading a recent article about estimating renal function in patients on new oral anticoagulants. The RE-LY trial comparing dabigatran versus warfarin in patients with atrial fibrillation excluded patients with creatinine clearance (CrCl) < 30 ml/min. (Recommendations in the current package insert are somewhat more liberal.) This is important, since dabigatran is eliminated almost entirely by the kidneys and can build up in patients with significant renal failure, causing over-anticoagulation. In fact, many patients who develop severe or fatal hemorrhage on the drug are elderly and have renal insufficiency.
The method used in the RE-LY trial to determine renal function was the Cockcroft-Gault formula. This equation uses the patient’s weight, age, gender and serum creatinine to estimate the CrCl. There are a number of online calculators that make it easy to do the math, including this one from MDCalc. Certainly, anyone being started on dabigatran should have their CrCl determined by the formula and documented in the medical record.