Elevation of Prolactin Levels by Atypical Antipsychotics

Abstract

OBJECTIVE: Atypical antipsychotics are thought not to elevate prolactin levels. The authors examined data suggesting that atypical antipsychotics do elevate prolactin levels but more transiently than typical antipsychotics. METHOD: Prolactin levels in 18 male patients with schizophrenia who were receiving atypical antipsychotics were monitored over the 24-hour period following administration of their daily oral dose of risperidone, olanzapine, or clozapine. RESULTS: The baseline prolactin levels in patients receiving risperidone (mean=27 ng/ml, SD=14) were abnormally high, but baseline prolactin levels in patients receiving olanzapine (mean=9 ng/ml, SD=5) and clozapine (mean=9 ng/ml, SD=5) were not high. All three atypical antipsychotics caused a doubling of prolactin levels over baseline levels 6 hours after medication administration. CONCLUSIONS: These data suggest that these atypical antipsychotics raise prolactin levels, although the increases with olanzapine did not reach statistical significance. Th...