When caring for a client newly prescribed furosemide, what should the nurse monitor most closely?

When a client is newly prescribed furosemide, monitoring potassium levels is crucial due to the medication's mechanism of action. Furosemide is a loop diuretic that promotes diuresis by inhibiting sodium and chloride reabsorption in the kidneys, which leads to increased urine production. This diuretic effect can result in significant electrolyte loss, particularly potassium.

Hypokalemia, or low potassium levels, is a common and potentially serious side effect of furosemide use. Low potassium levels can lead to various complications, including muscle weakness, arrhythmias, and other cardiac issues. Therefore, monitoring potassium levels helps ensure that the client remains within a safe range and allows for timely intervention if levels drop dangerously low.

While edema, heart rate, and clubbing of fingers are also relevant to a patient’s overall health, they do not carry the same immediate risk associated with the electrolyte imbalances caused by furosemide. Edema may improve over time as the medication takes effect, heart rate changes might occur but are less specific to the medication’s side effects, and clubbing generally relates to chronic conditions rather than acute side effects of furosemide. Thus, potassium level monitoring is the priority in this scenario.