Possible individual and gender differences in the small increases in plasma prolactin levels seen during clozapine treatment

Jose De Leon, Francisco J. Diaz, Richard C. Josiassen, George M. Simpson

Research output: Contribution to journalArticlepeer-review

21 Scopus citations

Abstract

In vitro, animal studies and acute short-term clinical studies suggest clozapine releases prolactin but the effect is much smaller than that of typical antipsychotics. Repeated early morning trough measures of plasma clozapine and prolactin levels on each subject were studied during the course of a double-blind dose-response clozapine study. After a 4-week 10 mg/day haloperidol trial and a one-week washout, treatment-refractory schizophrenics were successively randomized to 100, 300, or 600 mg/day of clozapine for a 16-week treatment. The statistical analyses included 35 subjects (19 females and 16 males). The within-subject correlation of prolactin levels was 0.32 with clozapine levels and 0.75 with haloperidol levels. An increment of 100 ng/ml in clozapine level yielded an average increment of 0.45 ng/ml of prolactin levels in females and of 0.15 ng/ml in males. An increment of 1 ng/ml in haloperidol level yielded an average increment of 2.6 ng/ml of prolactin levels in females and of 1.5 ng/ml in males. At least one fourth of patients demonstrated a significant and strong (r > 0.6) correlation between clozapine and prolactin levels. This study suggests that clozapine has effects on prolactin levels but effects are small and may be more evident in some individuals, particularly females.

Original languageEnglish
Pages (from-to)318-325
Number of pages8
JournalEuropean Archives of Psychiatry and Clinical Neuroscience
Volume254
Issue number5
DOIs
StatePublished - Oct 2004

Bibliographical note

Funding Information:
■ Acknowledgements This study was supported by the grant from the US National Institute of Health MH-47162 to GMS and RCJ. The Sandoz Research Institute provided free medication. The authors are grateful to Albert R. Di Dario, Superintendent of Norristown State Hospital for administrative support and to Robert W. Ehlers, R. N. for his help in the study particularly with blood samples.

Keywords

  • Clozapine
  • Haloperidol
  • Prolactin
  • Schizophrenia
  • Women

ASJC Scopus subject areas

  • Psychiatry and Mental health
  • Biological Psychiatry
  • Pharmacology (medical)

Fingerprint

Dive into the research topics of 'Possible individual and gender differences in the small increases in plasma prolactin levels seen during clozapine treatment'. Together they form a unique fingerprint.

Cite this