For which medication should a nurse withhold administration for a client with a potassium level of 3.2 mEq/L?

In the case of a client with a potassium level of 3.2 mEq/L, withholding furosemide is a critical action. Furosemide is a loop diuretic that can further deplete potassium levels, potentially exacerbating hypokalemia, which is already present in this client. Hypokalemia can lead to serious complications, including cardiac arrhythmias, muscle weakness, and fatigue. Therefore, administering furosemide to a patient with low potassium would not only fail to address the underlying issue but could also worsen their condition.

The other medications listed may also have considerations regarding potassium levels, but their direct relationship to the risk of further lowering potassium does not match the immediate concern posed by furosemide in this scenario. For instance, while digoxin can have potent effects on the heart and its efficacy can be influenced by potassium levels, the pressing issue here is the significant risk of worsening hypokalemia with furosemide. Lisinopril and amiodarone have differing mechanisms and effects that do not pose the same immediate risk based on the provided potassium level. Thus, prioritizing patient safety by withholding furosemide is the key rationale in this situation.