The acetate salt of a synthetic fluorinated corticosteroid with antiinflammatory and antiallergic activities. As a glucocorticoid-receptor agonist, fludrocortisone binds to cytoplasmic receptors, translocates to the nucleus, and subsequently initiates the transcription of glucocorticoid-responsive genes such as lipocortins to inhibit phospholipase A2 (PLA2). Inhibition of PLA2 activity prevents the release of arachidonic acid, a precursor of eicosanoids such as prostaglandins and leukotrienes; eicosanoids are important mediators in the pro-inflammatory response mechanism. As a mineralocorticoid-receptor agonist, this agent stimulates Na+ reabsorption and water retention and K+ and H+ secretion in the distal tubules and collecting ducts of the kidney.