What are the most commonly used synthetic mineralocorticoids?

Most Commonly Used Synthetic Mineralocorticoids

The most commonly used synthetic mineralocorticoid is fludrocortisone (9α-fludrocortisone acetate, brand name Florinef), which is the standard mineralocorticoid replacement therapy for conditions requiring mineralocorticoid supplementation. 1

Primary Synthetic Mineralocorticoid

Fludrocortisone (Florinef)

• Dosage and administration:

  • Standard dosage range: 0.05-0.2 mg once daily 1, 2
  • Usually administered as a single oral dose in the morning 1
  • Available in tablet forms of 0.1 mg and 0.05 mg 1
  • Refrigeration was previously recommended but is not strictly necessary (decay rate only 0.1% in 6 months at room temperature) 1

• Clinical applications:

  • Primary adrenal insufficiency (Addison's disease) 3
  • Salt-losing forms of congenital adrenal hyperplasia 3, 4
  • Severe hypotension to restore adequate plasma volume 3
  • Management of mineralocorticoid deficiency in any condition with aldosterone deficiency 2

• Monitoring parameters:

  • Blood pressure (supine and standing positions)
  • Serum electrolytes (sodium and potassium)
  • Presence of peripheral edema
  • Plasma renin activity (PRA) - aim for upper normal range 2, 5
  • Salt cravings or lightheadedness 1

Other Mineralocorticoid Agents

Desoxycorticosterone Pivalate (DOCP)

• Used primarily in veterinary medicine for canine hypoadrenocorticism
• More effective at suppressing plasma renin activity compared to fludrocortisone in dogs 5
• Not commonly used in human medicine

Special Considerations for Fludrocortisone Use

Dose Adjustments

• Pregnancy: Higher doses (up to 500 μg daily) may be needed in the last trimester due to progesterone's anti-mineralocorticoid effects 1, 2
• Hot weather: Dose adjustments may be needed in high ambient temperatures to avoid sodium depletion 2
• Hypertension: Dose reduction is recommended, but monitor for hyperkalemia 2

Drug Interactions

• Medications to avoid or use with caution:
  • Diuretics
  • Acetazolamide
  • Carbenoxolone and licorice
  • NSAIDs
  • Drospirenone-containing contraceptives (may need more fludrocortisone) 1

Potential Side Effects

• Hypernatremia
• Hypokalemia
• Hyperglycemia
• Congestive heart failure (with chronic use) 3
• Hypertension

Monitoring Mineralocorticoid Replacement

Clinical Assessment

• Regular monitoring of blood pressure and electrolytes
• Assessment for peripheral edema
• Evaluation of salt cravings or orthostatic symptoms

Laboratory Monitoring

• Plasma renin activity (PRA) - the gold standard for monitoring mineralocorticoid treatment 2, 5
• Serum sodium and potassium levels
• Consider more frequent monitoring during:
  • Initial treatment phase
  • Pregnancy
  • Hot weather
  • When taking medications that may interact with fludrocortisone

Common Pitfalls in Mineralocorticoid Replacement

• Under-replacement is common and may lead to recurrent adrenal crises 1
• Over-replacement with mineralocorticoids can lead to hypertension and edema
• Glucocorticoid over-replacement is sometimes used to compensate for mineralocorticoid under-replacement, which should be avoided 1
• Essential hypertension should be treated with vasodilators rather than stopping mineralocorticoid replacement 1

Mineralocorticoid replacement is a critical component of therapy for patients with adrenal insufficiency, and proper dosing and monitoring are essential to prevent complications related to both under- and over-replacement.