Hi TaintedLuv, The medicine that youre on will affect the results of any further cortisol tests, for some reason all around the world doctors seem to have very little knowledge of how to test for Adrenal insufficiency and are often completely unaware that a normal cortisol result does not rule out Adrenal insufficiency! And that it essential that the test is done at the right time of day, and that other tests have to be done at the same time as well.
What should be done is explained in this article
http://www.suite101.com/content/adrenalinsufficiency-a1543 It says
When adrenal insufficiency is suspected, blood for an AM cortisol level along with an ACTH level and an aldosterone level is drawn. With a normal range of 9-25, mcg/dl, blood cortisol levels higher than 19 generally rule out the possibility of adrenal insufficiency. Levels lower than 3 suggest adrenal insufficiency, and levels between 3-19 are indeterminate. In primary adrenal insufficiency, the blood ACTH level is high. A low cortisol with a high ACTH is sufficient to diagnose primary adrenal insufficiency; a low ACTH with a low cortisol level is seen in secondary adrenal insufficiency. Further tests can be used to differentiate pituitary from hypothalamic causes in secondary conditions.
Regardless of the cortisol level, if adrenal insufficiency is highly suspect, an ACTH stimulation test is performed. In this test the patient is given an injection containing cosyntropin, a synthetic form of ACTH. Cortisol levels are tested prior to administering the drug and at 30 and 60 minutes after the ACTH is given. In adrenal insufficiency the rise is blood cortisol levels is negligible. A longer version of the test can be used to determine if abnormal results are due to pituitary or adrenal disease.
Patients with adrenal insufficiency are also tested for adrenocorticol antibodies (ACA) and antibodies to the hormone 17-hydroxylase. In autoimmune adrenal insufficiency, these antibodies are present with highest levels seen early in the disease course. Imaging studies are used to help evaluate damaged adrenal glands. In autoimmune adrenal insufficiency, the glands are reduced in size.
Note: Blood levels of cortisol are decreased in hypothyroidism and increased in hyperthyroidism--levels improve when thyroid hormone levels are corrected. Cortisol may also be increased in pregnancy, in emotional stress, various illnesses, and by oral contraceptives, hydrocortisone, and spironolactone. A normal salt diet should be followed for 2-3 days before having blood drawn. Salivary cortisol tests are more accurate when levels are elevated than in conditions in which cortisol is low.
ACTH levels are decreased by dexamethasone, prednisone, hytdrocortisone, prednisolone, methylprednisolone and megestrol acetate. ACTH levels rise with the use of amphetamines, insulin, levodopa, metoclopromade, and RU 486.
In shift workers the AM and PM cortisol and ACTH levels will be reversed.
So its very important not to be taking medications that effect cortisol results, that the test is done early in the morning, around 8 am because cortisol levels decline throughout the day, so the test needs to be done close to when you wake up, if there to give a true indication of what your highest cortisol levels are,
More information on the Cortisol test can be found here
http://www.labtestsonline.org/understanding/analytes/cortisol/sample.html
Serum ACTH and Serum Aldosterone must be done at the same time otherwise without doing these tests as well, nobody going to be able to work out whats going on, but the reality is a lot of doctors dont know this and dont do them. Im not aware of any literature that says that the cortisol test needs to be done fasting when testing for Adrenal insufficiency.
More information on the ACTH stimulation test, which will need to be done if there are any doubts about the initial results can be found here
http://www.acthstimulationtest.com/
On this site theres a very good graph that shows how the different results for the likes of cortisol Aldosterone, DHEA etc can be used to tell between Primary, Secondary and Tertiary Adrenal insufficiency
http://en.wikipedia.org/wiki/Adrenal_insufficiency
Hope this helps, like a say a lot of doctors dont know how to test properly for Adrenal Insufficiency so its very important that you do, and can make sure its being done properly!!
All the best
