Dexamethasone Suppression Test
Alternate Names : ACTH Suppression Test, Cortisol Suppression Test, DST
How is the Test Performed?
There are two different types of dexamethasone suppression tests: the low dose test and the high dose test. Each type can either be done in a overnight or standard (3 day) way.
For the low dose, overnight method, 1 mg of dexamethasone is given at 11 P.M., and the blood is drawn at 8 A.M. for a cortisol measurement (see venipuncture).
In the standard, low dose method, urine is collected at 24-hour intervals over 3 days for measurement of cortisol. On day 2, a low dose (0.5 mg) of dexamethasone is given by mouth every 6 hours for 48-hours.
For the high dose overnight method, a baseline cortisol is measured on the morning of the test and then 8 mg of dexamethasone is given at 11 P.M.. Blood is drawn at 8 A.M. for a cortisol measurement (see venipuncture). For the standard high dose test, urine is collected at 24-hour intervals over 3 days for measurement of cortisol. On day 2, a high dose (2 mg) of dexamethasone is given by mouth every 6 hours for 48-hours.
|
