Background: To study the influences of drug type and gender on the neuroend
ocrine response to neuroleptic treatment we compared the endocrine actions
of two neuroleptics with different receptor affinity profiles-a substituted
benzamide, amisulpride, a selective D-2-like dopamine antagonist; and a th
ioxanthene, flupenthixol, a mixed D-1/D-2-like antagonist also blocking ser
otonin, H-1, and D-1 receptors-on anterior pituitary hormone secretion in s
chizophrenic patients (DSM-III-R).
Methods: Blood was withdrawn at 15-min intervals to assess basal secretion
of prolactin, growth hormone (GH), and thyroid-stimulating hormone (TSH). F
our hundred micrograms of thyrotropin-releasing hormone (TRH) was injected
IV to investigate drug effects on TRH-stimulated secretion of prolactin TSH
, and GH.
Results: Prolactin plasma levels were markedly elevated in both treatment g
roups. In female, but not in male patients, this elevation was significantl
y more pronounced under amisulpride than under flupenthixol, The prolactin
response to TRH was significantly blunted by amisulpride only in male subje
cts. While basal TSH secretion was significantly increased by both compound
s, TRH-stimulated TSH secretion was elevated only in patients treated with
amisulpride. Low basal prolactin levels predicted improvement of negative s
ymptoms in patients treated with amisulpride.
Conclusions: Amisulpride's more pronounced endocrine effects may be a refle
ction of its distinguished pharmacology and pharmacokinetics. Biol Psychiat
ry 1999;45: 89-97 (C) 1999 Society of Biological Psychiatry.