Cortisol measurements in patients receiving oral corticosteroid replacement treatment.

Eight women receiving corticosteroid replacement in the form of 50 mg cortisone acetate or 40 or 50 mg cortisol orally daily were studied. The cortisol "urinary productions rate" and "blood production rate" measurements suggested that the steroid was rapidly metabolized in the gut or in the first passage through the liver. The 24-hour mean plasma cortisol concentration obtained from blood samples drawn every 20 minutes over a 24-hour period and the "blood production rate" were close to the values in normal women. However, since the normal 24-hour plasma cortisol concentration profile could not easily be reproduced and this may be relevant for optimal physiologic function, the patient's clinical status will continue to be the main guide to the choice of the appropriate replacement dose.