Synacthen is a drug, which is used to stimulate the production of cortisol by the adrenal glands. Synacthen works in a similar way to Adrenocorticotropic Hormone (ACTH). The test measures the rise in cortisol to determine whether the adrenal glands are working effectively to produce cortisol.
The test is used primarily to diagnose Addison’s disease; the results of the test determine how much cortisol is being produced by the adrenal glands.
The test is usually ordered when a doctor suspects that a patient is not producing enough cortisol; symptoms of this include tiredness, weight loss, sickness and lethargy.
The test is done by taking a sample of blood from a vein in the arm; the patient will be asked to lie down during the course of the test. A canula (a small tube) with a valve will be inserted into a vein in the arm; a sample of blood is taken from the vein and then a solution containing Synacthen is injected into the vein and a second sample is taken 30 minutes later; a final sample is then taken 60 minutes after. The test is used to measure the levels of cortisol.
A regular rise in cortisol indicates that the adrenal glands are working normally; the regular range will be determined by doctors. If the rise in cortisol is low or non-existent, this indicates that the patient has got Addison’s disease.