What assessment finding demonstrates a therapeutic effect of fludrocortisone in the treatment of Addison's disease?

Rationale: A. Increased potassium level: Fludrocortisone acts as a mineralocorticoid, promoting sodium retention and potassium excretion in the distal renal tubules. An increase in potassium would indicate poor therapeutic effect or inadequate dosing, rather than a positive response. B. Decreased fluid retention: Fludrocortisone promotes sodium and water retention to maintain blood pressure and fluid balance in Addison’s disease. A decrease in fluid retention would suggest insufficient drug effect, which is contrary to the desired therapeutic outcome. C. Decrease calcium level: Fludrocortisone has minimal direct effect on calcium metabolism. Changes in calcium are not a relevant indicator of therapeutic efficacy in the management of Addison’s disease. D. Increased sodium level: Fludrocortisone’s mineralocorticoid action enhances sodium reabsorption in the kidneys, which helps correct hyponatremia commonly seen in Addison’s disease. An increased sodium level reflects effective therapy and improved electrolyte balance, indicating a positive therapeutic response.