Dabigatran and the elderly
August 2, 2011, 5:10 pm
The Use of Dabigatran in Elderly Patients. Legrand M et al. Arch Intern Med July 25 2011;171:1285-88.
This short but important article present 2 cases of over-anti-coagulation in elderly patients, and makes the following key points:
- Dabigatran is eliminated predominantly by the kidneys.
- The RE-LY trial, the major study evaluating the use of dabigatran etexilate (Pradaxa) as an anticoagulant to prevent stroke in patients with atrial fibrillation, excluded patients with creatinine clearance (CrCl) less than 30 ml per minute.
- It is unreasonable to assume that all elderly (> 75 years old) patients started on dabigatran will have a specific CrCl measured, and renal impairment may not be apparent from the creatinine level alone in this patient population.
- Therefore, the risk of overdose in significantly increased in this population, especially since there is not a good test to measure the precise anticoagulation effect of dabigatran, and there is no specific antidote.
As an accompanying commentary states:
Impaired renal function, often in the presence of normal serum creatinine level, is common yet frequently overlooked among elderly patients. Low body weight and advanced age further exaggerates the magnitude of underascertainment of impaired renal function.
Most important reading.