Newer antipsychotics and glucose metabolism: a comparison between olanzapine and risperidone

In order to estimate the degree of glucose tolerance impairment, oral glucose tolerance test was conducted in the group of 15 schizophrenic patients taking olanzapine, the group of 15 schizophrenic patients taking risperidone and in the group of 14 healthy volunteers. In the olanzapine group the tolerance was impaired in 33% of the patients, contrary to the risperidone group in which impairment amounted to 20% of the patients. The authors discuss possible mechanisms responsible for impaired glucose tolerance in patients taking newer antipsychotic drugs.