Sample Collection and Processing for Cortisol TestingĪdrenal function tests should be started in the morning to avoid possible circadian fluctuations in cortisol.ĭraw all blood samples into plain red-top tubes and allow blood to clot at room temperature for approximately one hour. If Azium® is injected intravenously, do so very slowly.Ĭollect additional blood samples 6 and 8 hours later. Dexamethasone sodium phosphate is recommended for the high-dose DST.

Inject 0.1 mg/kg of dexamethasone intramuscularly or intravenously.Įither dexamethasone sodium phosphate or Azium® (dexamethasone with polyethylene glycol) can be used. This test, combined with results from the LDDST or ACTH-response test, is used to differentiate between pituitary-dependent hyperadrenocorticism and adrenocortical tumor(s). High-Dose Dexamethasone-Suppression Test (HDDST) measuring Cortisol

Inject 0.015 mg/kg of dexamethasone intramuscularly or intravenously.Įither dexamethasone sodium phosphate or Azium® (dexamethasone with polyethylene glycol) can be used.Ĭollect additional blood samples at 6 and 8 hours. Severe illness, certain medications, etc. This is the preferred test for the initial diagnosis of Cushing’s syndrome. Low-Dose Dexamethasone-Suppression Test (LDDST) measuring Cortisol Inject 0.25 mg Cortrosyn® or 5 ug/kg intramuscularly or 2.2 IU/kg of ACTH Gel intramuscularly.Ĭollect samples 1 hour after Cortrosyn® injection or 1 & 2 hours after compounded ACTH Gel preparations. ACTH-Response tests to monitor Trilostane® treatment should be started 4-6 hours after Trilostane® administration.ĭraw a baseline blood sample in a plain red-top tube for serum. It should be used to evaluate adrenocortical function after treatment for Cushing’s syndrome with o,p’-DDD (mitotane, Lysodren®) or Trilostane® and to diagnose iatrogenic Cushing’s syndrome.

This test may be used for diagnosing Addison’s disease and Cushing’s syndrome.

Adrenals function