Abstract
The bioavailability of dexamethasone (DEX) has recently been demonstrated to be a critical factor in determining Dexamethasone Suppression Test (DST) status in psychiatric patients. This brief review focuses on several aspects of DEX bioavailability as they relate to the use of the DST in neuroendocrine research. Several methodologies, including radioimmunoassay, high-performance liquid chromatography, and gas chromatography-mass spectrometry are available for quantification of DEX in biological fluids, although few detailed comparisons between methods have been reported. Surprisingly, little systematic research on the metabolism of DEX has been reported, but it appears that hepatic rather than renal mechanisms are the major source of DEX elimination. The marked variability in serum DEX levels following oral administration in psychiatric patients is also observed in normal controls and patients with Cushing's syndrome. A variety of drugs can modify serum DEX levels and thereby alter the effectiveness of DEX in suppressing serum cortisol levels. Simultaneous measurement of serum DEX and cortisol levels appears to be necessary for the appropriate evaluation of DST results. This procedure may help explain many of the inconsistencies in recent DST research.
Original language | English (US) |
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Pages (from-to) | 373-385 |
Number of pages | 13 |
Journal | Biological psychiatry |
Volume | 22 |
Issue number | 3 |
DOIs | |
State | Published - Mar 1987 |
Funding
Pmm the Department of Psychiatry, Case Western R-e University, Cleveland, OH. Supported by NIGH GITIII~SM H-41683-01 and MH-41684. H.Y.M. is a ncipient of USPHS Research Career Scientist Award MH 47,808. Address mplblt quests to h. Martin T. Lowy, Department of Psychiatry, Case Western Reserve University, 2040 Abingtoo Road, Cleveland, OH 44106. Received March 27, 1986; revised July 14, 1986.
ASJC Scopus subject areas
- Biological Psychiatry