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Specific effects of escitalopram on neuroendocrine response

Psychopharmacology volume 207, Article number: 27 (2009) Cite this article

Abstract

Purpose

Citalopram, a selective serotonin reuptake inhibitor, is used as a neuroendocrine probe in human subjects to assess serotonin function as reflected in prolactin and plasma cortisol release. Citalopram is a racemic mixture of equal proportions of the S(+) and R(−) enantiomers. Inhibition of serotonin reuptake and, consequently, antidepressant activity is associated, almost exclusively, with the S(+) enantiomer (“escitalopram”). Studies in animal models indicate that the presence of the R(−) isomer may interfere with the serotonin reuptake activity of escitalopram. The current study compared the neuroendocrine effects of citalopram and escitalopram in healthy human volunteers.

Methods

Plasma cortisol and prolactin levels following a single oral dose of citalopram (40 mg) or escitalopram (20 mg) were compared in samples taken every 15–30 min over a period of 240 min. Plasma citalopram concentration was determined at the same intervals.

Results

Escitalopram and citalopram caused equivalent increases in plasma cortisol and prolactin. The administration of dexamethasone prior to the escitalopram challenge blocked the evoked increase in cortisol.

Conclusion

This is the first study to prove that a single dose of escitalopram acts centrally and not peripherally, providing further support of the use of oral escitalopram as a probe for brain serotonergic function.

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Acknowledgements

We are grateful to Diana Hall, Registered Technologist, for performing the hormone assays. We are also grateful to Lundbeck Canada, Inc., for providing an unrestricted grant in support of this study. Lundbeck Canada, Inc., was, however, not responsible for creation of the study protocol, acquisition of the data, including the hormonal and citalopram assays, the data analysis, data interpretation, or writing of the manuscript, which were solely performed by the authors.

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Affiliations

  1. Providence Care Centre-Mental Health Services, Kingston, ON, Canada

    Emily R. Hawken, James A. Owen & Nicholas J. Delva

  2. Department of Pharmacology and Toxicology, Queen’s University, Kingston, ON, Canada

    James A. Owen

  3. Department of Psychiatry, Queen’s University, Kingston, ON, K7L 3N6, Canada

    Emily R. Hawken, James A. Owen & Nicholas J. Delva

  4. Department of Medicine (Endocrinology), Queen’s University, Kingston, ON, Canada

    Robert W. Hudson

  5. Department of Psychiatry, Dalhousie University, Halifax, NS, Canada

    Nicholas J. Delva

Authors
  1. Emily R. Hawken
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  2. James A. Owen
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  3. Robert W. Hudson
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  4. Nicholas J. Delva
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Corresponding authors

Correspondence to James A. Owen or Nicholas J. Delva.

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Hawken, E.R., Owen, J.A., Hudson, R.W. et al. Specific effects of escitalopram on neuroendocrine response. Psychopharmacology 207, 27 (2009). https://doi.org/10.1007/s00213-009-1633-1

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  • DOI: https://doi.org/10.1007/s00213-009-1633-1

Keywords

  • Citalopram
  • Escitalopram
  • Neuroendocrine challenge
  • Cortisol
  • Prolactin
  • Serotonin