Effects of desipramine and fluvoxamine treatment on the prolactin response to tryptophan. Serotonergic function and the mechanism of antidepressant action.
It has been hypothesized that enhancement of brain serotoninergic (5-HT) function is involved in the mechanism of action of some antidepressants. To test this, the prolactin response to intravenously administered tryptophan, a clinical measurement of 5-HT function, was assessed before and during antidepressant treatment. Depressed patients received the tricyclic desipramine hydrochloride (N = 24) or the 5-HT reuptake inhibitor fluvoxamine maleate (N = 30). The prolactin response was significantly enhanced after long-term treatment (4 weeks) but not as reliably increased after short-term (1-week) desipramine treatment. Fluvoxamine enhanced the prolactin response after both short- and long-term treatment. Enhancement of the prolactin response was not clearly correlated with clinical improvement. The results of this study are consistent with preclinical evidence of enhanced 5-HT function during treatment with these classes of antidepressants, but also indicate that enhanced 5-HT function is not a sufficient condition for antidepressant efficacy.
Price
L H
LH
Yale University School of Medicine, Clinical Neuroscience Research Unit, New Haven, Conn.
Charney
D S
DS
Delgado
P L
PL
Anderson
G M
GM
Heninger
G R
GR
D000928:Antidepressive Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002986:Clinical Trials as Topic; D003866:Depressive Disorder / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D003891:Desipramine / Q000494:pharmacology / Q000627:therapeutic use*; D004311:Double-Blind Method; D016666:Fluvoxamine; D006801:Humans; D010091:Oximes / Q000494:pharmacology / Q000627:therapeutic use*; D011388:Prolactin / Q000097:blood*; D012701:Serotonin / Q000502:physiology; D012702:Serotonin Antagonists / Q000494:pharmacology / Q000627:therapeutic use; D013997:Time Factors; D014364:Tryptophan / Q000494:pharmacology*
D000928:Antidepressive Agents; D010091:Oximes; D012702:Serotonin Antagonists; D012701:Serotonin; D014364:Tryptophan; D011388:Prolactin; D016666:Fluvoxamine; D003891:Desipramine