procedure for dexamethasone plasma and urine levels in man. Eur

intravenous administration to a healthy man. Although methylprednisolone possesses pharmacological properties similar to thoseof dexamethasone, it is unlikely that these two agents would deliberately be used in combi-nation in treating a patient. Therefore, we believe it is a good choicefor use as an internal standard. The chromato-graphic procedure described differs from those previously reported by the use ofa fast, efficient, and inexpensive solid-phase extraction step. The process takes approximately 40 mm to the completionof the drying step, so that about 20 samples of plasma canbe analyzedwithin an 8-h work day. We believe this procedure is suitable for clinical applications and offers significant advantages over previously described methods