Instruction for Low Dose (Overnight) Dexamethasone Suppression Test

What is the purpose of the test?  

Your doctor had ordered this test to determine if you have Cushing's syndrome.

Cushing's syndrome is a collection of signs and symptoms due to prolonged exposure to cortisol. Cortisol is a natural steroid hormone produced by the adrenal glands.

What do I have to do?  

  1. Ensure you have collected 1mg of Dexamethasone from the pharmacy. You can collect them either from TTSH B2B main pharmacy (during office hours) or B1 emergency pharmacy (after office hours).
  2. 1 day before your scheduled test date, take the 1mg of Dexamethasone at 11pm.
  3. Come to TTSH Clinic B2B on the scheduled test date (which should be the morning after taking your tablets), between 8 to 8:30am, and register to have your blood test done.

It is important that the tablets and the blood test are taken at the correct time, otherwise the results of the tests may be unreliable. Your doctor may not be able to make the correct diagnosis if the results are unreliable and this may mean that the tests would need to be repeated.

Who do I contact if I have questions? 

If you have any questions or doubts, please call Tan Tock Seng Hospital Clinic B2B at 96571104.