Dose-dependent effects of olanzapine on QT intervals and plasma prolactin levels in Japanese patients with stable schizophrenia.

Abstract

OBJECTIVES:

There have been few reports regarding olanzapine (OLZ)-related QT prolongation and hyperprolactinemia. This study evaluated the dose-dependent effect of OLZ on QT interval and plasma prolactin (PRL) level in a single sample of patients with schizophrenia.

METHODS:

Twenty-six subjects treated with varying starting doses of OLZ were enrolled in the study. Following baseline assessments, which included completion of the Brief Psychiatric Rating Scale (BPRS), measurements of Body Mass Index (BMI), QT interval, electrolytes, fasting plasma glucose, PRL, hemoglobin A1c (HbA1c), total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL), and low density lipoprotein (LDL), the dose of OLZ was increased for each subject. The same parameters were evaluated following the increased dose treatment.

RESULTS:

A significant decrease was observed in BPRS score (p = 0.01) following treatment with an increased dose of OLZ. Significant increases were observed in BMI (p = 0.032), QTc (p = 0.031), and plasma PRL level (p = 0.028). The mean values of electrolytes, fasting plasma glucose, HbA1c, TC, TG, HDL and LDL treatment were unchanged by the switch to increased-dose OLZ treatment.

CONCLUSION:

We have demonstrated the dose-dependent effect of OLZ on the QT interval and the plasma PRL level of patients with schizophrenia.

• Authors: Yutaro Suzuki, Shin Ono, Takuro Sugai, Naoki Fukui, Junzo Watanabe, Nobuto Tsuneyama, Kazushi Sawamura, Toshiyuki Someya
• Journal: Human psychopharmacology (Hum Psychopharmacol) Vol. 26 Issue 6 Pg. 440-3 (Aug 2011) ISSN: 1099-1077 [Electronic] England
• PMID: 21823168 (Publication Type: Comparative Study, Controlled Clinical Trial, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2011 John Wiley & Sons, Ltd.

Chemical References

• Antipsychotic Agents
• Benzodiazepines
• Prolactin
• Olanzapine

Topics

• Adolescent
• Antipsychotic Agents (administration & dosage, adverse effects, therapeutic use)
• Benzodiazepines (administration & dosage, adverse effects, therapeutic use)
• Body Mass Index
• Dose-Response Relationship, Drug
• Female
• Humans
• Japan
• Long QT Syndrome (chemically induced)
• Male
• Olanzapine
• Prolactin (blood, drug effects)
• Psychiatric Status Rating Scales
• Schizophrenia (drug therapy)
• Young Adult