If a client's potassium level is 3.2 mEq/L, which medication should the nurse withhold?

With a potassium level of 3.2 mEq/L, the nurse should withhold furosemide, a diuretic that can lead to further potassium depletion. This medication functions by promoting increased urine production and can cause the kidneys to excrete more potassium, potentially worsening the client's hypokalemia. It’s crucial to maintain potassium levels within a normal range to ensure proper heart and muscle function, and administering furosemide in this scenario would pose a risk of serious complications such as cardiac arrhythmias or muscle weakness.

The other medications listed do not have such a direct impact on potassium levels and would not pose the same immediate risk in the context of a client with low potassium. While spironolactone is a potassium-sparing diuretic and could be safely given, aspirin and atorvastatin do not typically affect potassium levels significantly. Therefore, withholding furosemide is essential to prevent further exacerbation of the client's hypokalemia.