A client on torsemide reports cramping in the lower extremities. Which laboratory finding would you most likely expect?

A client on torsemide reports cramping in the lower extremities. Which laboratory finding would you most likely expect?

• A. Calcium level of 11 mg/dL
• B. Potassium level of 3.1 mEq/L
• C. Sodium level of 140 mEq/L
• D. pH level of 7.40

Answer: (B)

Loop diuretics like torsemide cause potassium wasting in the distal nephron. By blocking the Na-K-2Cl transporter in the thick ascending limb, they increase sodium delivery to the collecting ducts, which drives more potassium secretion into the urine. This leads to lower serum potassium (hypokalemia), and hypokalemia commonly manifests as muscle cramps, especially in the legs.

So a potassium level of 3.1 mEq/L fits best, reflecting the diuretic-induced potassium loss. The other values don’t align with this mechanism: a calcium of 11 mg/dL is elevated and not the typical result of loop diuretic action, while a normal sodium and a normal pH do not explain cramping driven by low potassium.