Patients diagnosed with adrenal insufficiency are generally treated with hydrocortisone in the range of 60 to 80 mg intravenously (IV), 3 to 4 times daily for a total dose of 200 to 300 mg per day. However, in a patient who has not had a cosyntropin stimulation test to confirm the diagnosis of adrenal insufficiency, hydrocortisone should be switched to dexamethasone 2 to 4 mg IV every 6 to 8 hours for three doses until that test can be completed. Since therapy with supraphysiologic doses of any corticosteroid for even as few as five days can result in adrenal suppression for up to 1 year following cessation of therapy, use of steroids should not be undertaken lightly and as such a stimulation test should be considered. The reason for switching from hydrocortisone to dexamethasone is that hydrocortisone directly interferes in the assay used by labs to determine cortisol levels in blood samples while dexamethasone does not.