List of products in the National Drug Code with proprietary name . Fludrocortisone is a man-made form of a natural substance (glucocorticoid) made by the body. It is used along with other medications (e.g., hydrocortisone) to treat low glucocorticoid levels caused by disease of the adrenal gland (e.g., Addison's disease, adrenocortical insufficiency, salt-losing adrenogenital syndrome). Glucocorticoids are needed in many ways for the body to function well. They are important for salt and water balance and keeping blood pressure normal. They are also needed to break down carbohydrates in your diet.