Which electrolytes should be closely monitored with amphotericin B therapy?

• A. Sodium and chloride
• B. Potassium and magnesium
• C. Calcium and phosphate
• D. Iron and copper

Answer: (B)

Amphotericin B is notably nephrotoxic and damages renal tubular function, which leads to wasting of electrolytes in the urine. The two most clinically important losses are potassium and magnesium, resulting in hypokalemia and hypomagnesemia. These imbalances can cause dangerous arrhythmias, muscle weakness, cramps, and other neuromuscular symptoms, so they’re the ones that clinicians monitor most closely during therapy. Regular labs should track potassium and magnesium levels, with prompt supplementation as needed and, if nephrotoxicity is a concern, consideration of a less nephrotoxic formulation or dose adjustments. While other electrolytes can be affected, potassium and magnesium are the primary monitoring focus due to their frequency of loss and immediate clinical impact.