Effects of oral racemic citalopram on neuroendocrine responses.
Citalopram, a selective serotonin reuptake inhibitor (SSRI), has been used as a neuroendocrine probe to assess serotonin (5-HT) function in human subjects. In an effort to characterize the oral citalopram challenge, we hypothesized that oral racemic citalopram would increase plasma cortisol, prolactin and adrenocorticotropic hormone (ACTH) concentrations; ACTH had not been measured in previous studies on the neuroendocrine effects of citalopram. Nine healthy male subjects initially received 20 mg of citalopram in an open-label study, and subsequently received placebo and 40 mg of citalopram in a single-blind, randomized, cross-over study. The administration of citalopram 20 mg failed to produce a significant neuroendocrine response but 40 mg resulted in reliably increased plasma cortisol concentrations. The 40 mg dose, however, did not reliably influence the levels of plasma prolactin or plasma ACTH. The results of this study indicate that caution should be used in accepting oral racemic citalopram as a potential presynaptic serotonergic challenge agent. Further studies are needed to fully determine the validity of racemic citalopram and the active enantiomer, escitalopram, as 5-HT probes.
Hawken
Emily R
ER
Providence Continuing Care Centre-Mental Health Services, 752 King Street, Kingston, Ontario, Canada K7L 4X3. hawkense@pccchealth.org
Owen
James A
JA
Van Vugt
Dean
D
Delva
Nicholas J
NJ
D000284:Administration, Oral; D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D015283:Citalopram / Q000008:administration & dosage*; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D008875:Middle Aged; D009490:Neurosecretory Systems / Q000187:drug effects* / Q000378:metabolism; D011388:Prolactin / Q000097:blood; D017367:Selective Serotonin Reuptake Inhibitors / Q000008:administration & dosage*; D016037:Single-Blind Method; D013997:Time Factors
D000324:Adrenocorticotropic Hormone; D015283:Citalopram; D006854:Hydrocortisone; D011388:Prolactin; D017367:Selective Serotonin Reuptake Inhibitors