As people age, their ability to filter blood, called the glomerular filtration rate (GFR) decreases. Drugs that are eliminated by the kidney can accumulate with declining GFR. The usual biomarker for estimating GFR is serum creatinine, and as it rises, it reflects a decrease in GFR. A recent case study presented in the Annals of Pharmacotherapy (April 2012) illustrated what can happen with a decline in GFR. An elderly woman with atrial fibrillation was receiving dabigatran to reduce the risk of stroke. She had congestive heart failure, type 2 diabetes, hypertension, among other diseases, and a history of chronic kidney disease (CKD). When she presented to the hospital emergency department, she was vomiting blood and was diagnosed with acute GI bleeding. Her serum creatinine was elevated (3.6mg/dL; normal range 0.7 – 1.2 mg/dL) and in review the medical records, had not been assessed just prior to starting dabigitran or within the following 2 months. For older adults, kidney function should be assessed at least once a year. For those with CKD, twice a year is appropriate for most. When initiating new drugs that require the kidneys for elimination from the body, kidney function should be assessed prior to starting therapy and with any change in medical status. Anticoagulant drugs are big contributor to adverse drug events in older individuals. Keep a close eye on kidney function for those receiving these drugs. For mobile device users, our application, ClotRx, provides a quick source to access this information (iTunes store).
Wednesday, May 30, 2012
Posted in Clinical Care