NCT00150527

Specific Effects of Escitalopram on Neuroendocrine Response

• Status: Completed
• Phase: —
• Study type: Observational
• Enrollment: 8 (actual)
• Sponsor: Queen's University · Academic / Other
• Sex: All
• Age: 18 Years – 59 Years
• Healthy volunteers: Accepted

Summary

Citalopram, a selective serotonin reuptake inhibitor (SSRI), is used as a neuroendocrine probe in human subjects to assess serotonin (5-hydroxytryptamine; 5-HT) function as reflected in prolactin and plasma cortisol release. Citalopram is a racemic mixture of equal parts of the S(+) and R(-) enantiomers. The S(+) form ("escitalopram") has been identified as being the active isomer and inhibitor of serotonin reuptake and consequently antidepressant activity is associated almost exclusively with the S-enantiomer. Escitalopram has been shown to be approximately twice as potent as citalopram at the primary, high-affinity binding site on the human serotonin transporter. Interestingly, investigations have suggested an antagonistic interaction of the R- and S-enantiomer at an allosteric binding site on the serotonin transporter. This antagonism has been shown in animal studies where the addition of R-citalopram to escitalopram treatments significantly counteracts the antidepressant and anti-anxiolytic effects of escitalopram. From these clinical and experimental data, the researchers can anticipate that escitalopram would increase cortisol and prolactin in the neuroendocrine challenge paradigm more effectively than citalopram.

Detailed description

See above.

Conditions

• Healthy

Interventions

Type	Name	Description
DRUG	Citalopram	40 mg, pill, single dose
DRUG	Escitalopram	20 mg, pill, single dose
DRUG	Dexamethasone	1 mg, pill, single dose
BEHAVIORAL	Cold Pressor Test	single test

Timeline

• Start date: 2005-09-01
• Primary completion: 2006-12-01
• Completion: 2007-12-01
• First posted: 2005-09-08
• Last updated: 2009-02-05

Locations

1 site across 1 country: Canada