Overnight Dexamethasone Suppression Test

ACTH Suppression Test, Cortisol Suppression Test, Dexamethasone Suppression Test (DST), DST (Dexamethasone Suppression Test)

How It Is Done

The night before your blood is drawn (usually at 11:00 p.m.), you will swallow a pill containing 1 milligram (mg) of dexamethasone. The next morning (usually at 8:00 a.m.), a health professional will draw a sample of your blood. Take the pill with milk or an antacid to help prevent an upset stomach or heartburn.

The health professional drawing blood will:

• Wrap an elastic band around your upper arm to stop the flow of blood. This makes the veins below the band larger so it is easier to put a needle into the vein.
• Clean the needle site with alcohol.
• Put the needle into the vein. More than one needle stick may be needed.
• Attach a tube to the needle to fill it with blood.
• Remove the band from your arm when enough blood is collected.
• Put a gauze pad or cotton ball over the needle site as the needle is removed.
• Put pressure to the site and then put on a bandage.

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Author:	Sydney Youngerman-Cole, RN, BSN, RNC	Last Updated August 3, 2006
Medical Review:	Caroline S. Rhoads, MD - Internal Medicine David C.W. Lau, MD, PhD, FRCPC - Endocrinology & Metabolism
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