Olanzapine-induced weight gain in patients with first-episode schizophrenia: a double-blind, placebo-controlled study of fluoxetine addition.
OBJECTIVE
Since olanzapine-induced weight gain may be attributable to the antagonistic activity of olanzapine at the serotonin-2C receptor, the authors hypothesized that it might be attenuated by addition of the selective serotonin reuptake inhibitor fluoxetine.


METHODS
First-episode hospitalized schizophrenia patients (N=30) were randomly assigned in an 8-week double-blind study of olanzapine, 10 mg/day, coadministered with either fluoxetine, 20 mg/day (N=15), or placebo (N=15).


RESULTS
The group receiving olanzapine plus fluoxetine showed significantly less improvement in positive and disorganized symptom dimensions than the group receiving olanzapine plus placebo. The two groups demonstrated similar and substantial gradual weight gains.


CONCLUSIONS
These results suggest that fluoxetine coadministration is clinically ineffective and cannot attenuate olanzapine-induced weight gain.
Poyurovsky
Michael
M
Research Unit, Tirat Carmel Mental Health Center, Israel.
Pashinian
Artashes
A
Gil-Ad
Irit
I
Maayan
Rachel
R
Schneidman
Michael
M
Fuchs
Camil
C
Weizman
Abraham
A
D000328:Adult; D014150:Antipsychotic Agents / Q000009:adverse effects*; D001569:Benzodiazepines; D015992:Body Mass Index; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D005473:Fluoxetine / Q000009:adverse effects / Q000627:therapeutic use*; D006760:Hospitalization; D006801:Humans; D008297:Male; D009765:Obesity / Q000139:chemically induced* / Q000517:prevention & control*; D000077152:Olanzapine; D010890:Pirenzepine / Q000009:adverse effects* / Q000031:analogs & derivatives* / Q000627:therapeutic use; D010919:Placebos; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000175:diagnosis / Q000188:drug therapy*; D012565:Schizophrenic Psychology; D017367:Selective Serotonin Reuptake Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome; D015430:Weight Gain / Q000187:drug effects*
D014150:Antipsychotic Agents; D001569:Benzodiazepines; D005473:Fluoxetine; D000077152:Olanzapine; D010890:Pirenzepine; D010919:Placebos; D017367:Selective Serotonin Reuptake Inhibitors