Fludrocortisone Therapy in Postural Orthostatic Tachycardia Syndrome (POTS)

Mechanism of Action and Efficacy

Fludrocortisone acts as a mineralocorticoid that stimulates renal sodium retention and expands plasma volume, thereby improving orthostatic tolerance and reducing symptoms of orthostatic intolerance in POTS patients, according to the American College of Cardiology 1
The expanded fluid volume from sodium retention helps counteract the excessive venous pooling that occurs in POTS patients upon standing, which contributes to the compensatory tachycardia, as recommended by the American College of Cardiology 1

The American College of Cardiology recommends a dose of 0.1-0.2 mg of fludrocortisone taken once daily at night (up to 0.3 mg maximum) for orthostatic intolerance in POTS, with a strength of evidence based on small observational studies and one double-blind trial 1, 2, 3

Fludrocortisone should always be used in conjunction with salt loading for optimal effect, with a recommended salt intake of 5-10 g (1-2 teaspoons) of table salt per day through liberalized dietary sodium, as suggested by the American College of Cardiology 1, 2
The combination therapy of fludrocortisone and salt loading works synergistically with fluid intake of 2-3 liters of water or electrolyte-balanced fluids daily, and head-up tilt sleeping by elevating the head of the bed 4-6 inches (10-15 cm) to prevent nocturnal polyuria and maintain favorable fluid distribution, according to the American College of Cardiology and European Heart Journal 1, 2

Careful monitoring for hypokalemia is critical when using fludrocortisone, as the drug increases urinary potassium excretion, with regular electrolyte monitoring essential to prevent this potentially serious side effect, as recommended by the American College of Cardiology 1
Supine hypertension is a major limiting factor for fludrocortisone use, and other medications should be used before fludrocortisone in such cases, with consideration of the patient's history of hypertension, renal disease, heart failure, or cardiac dysfunction, according to the European Heart Journal and Circulation 2, 3