fludrocortisone suppression test

Indications

• evaluation of hyperaldosteronism

Procedure

• administer fludocortisone 0.5 mg orally every 6 hours for 4 days along with sodium & potassium supplementation
• measure serum cortisol at 7 AM & 10 AM & plasma aldosterone & plasma renin at 10 AM on day 4

Interpretation

• test confirms hyperaldosteronism if
  • plasma aldosterone > 6 ng/dL
  • plasma renin < 1 ng/mL/hour
  • serum cortisol at 10 AM lower than at 7 AM

More general terms

• provocative clinical test

Additional terms

• fludrocortisone (Florinef)

Components

• aldosterone in serum/plasma
• renin in plasma
• cortisol in serum