does dexamethasone affect cortisol level?
<answer> Yes <context> A normal response to Dexamethasone is still suppression of Cortisol to less than 50 nmol/L. Synacthen tests: normal response is cortisol above 420 nmol/L on 30-minute sample. Consider pituitary failure if low baseline cortisol, especially if below 170 nmol/L in morning.