In a patient on mineralocorticoid therapy, what finding best suggests a therapeutic effect?

In the context of mineralocorticoid therapy, an improved sodium level is a key indicator of therapeutic effect. Mineralocorticoids, such as aldosterone, play a critical role in regulating sodium and potassium balance in the body. They increase sodium reabsorption in the kidneys, which can lead to elevated sodium levels in the bloodstream.

A sodium level of 138 mEq/L is typically considered within the normal range, suggesting the successful maintenance of sodium homeostasis, particularly in patients who may have previously experienced hyponatremia (low sodium levels). In patients receiving mineralocorticoids, an optimal sodium level signifies that the therapy is effectively promoting sodium retention, thereby providing therapeutic benefit.

While the other parameters like red blood cell count, chloride levels, and prothrombin time might change based on various factors, they do not specifically reflect the direct therapeutic effects of mineralocorticoids in the same way sodium levels do. Therefore, a sodium level within the normal range confirms that the mineralocorticoid therapy is functioning as intended to stabilize electrolyte balance.