Elderly Man with Hyperkalemia Who Takes Digoxin

Author: Joshua Schwimmer, M.D., FACP, FASN

A 70-year-old man with advanced prostate cancer develops bilateral ureteral obstruction and acute on chronic renal failure.

His potassium rises to 7.7 mEq/L with peaked T-waves on electrocardiogram. His medications include digoxin.

The most appropriate and safest initial therapy is:
1. Hemodialysis
2. Percutaneous nephrostomy placement
3. Kayexalate
4. Intravenous glucose and regular insulin
5. Intravenous calcium gluconate

Answer: (highlight the line below with the mouse to see the answer)
4. Intravenous glucose and regular insulin.

#1, #2, and #3 cannot usually be performed soon enough and/or may not reduce the serum potassium quickly enough. #5 (calcium gluconate) is usually the initial therapy of choice, but intravenous calcium should be avoided or used cautiously when patients are on digoxin.

Published: 11/01/2006