The brain metabolic patterns of clozapine- and fluphenazine-treated femalepatients with schizophrenia: Evidence of a sex effect

The regional cerebral glucose metabolic rates of clozapine-treated and flup henazine-treated women with schizophrenia and normal controls were obtained by positron emission tomography (PET) using [F-18]-2-fluro-2-deoxy-D-gluco se (FDG) as the tracer. The regional metabolic patterns were compared to ea ch other and to the changes previously observed in men. In women, as in men , both clopazine- and fluphenazine-treatment were associated with lower met abolism in the superior prefrontal cortex and higher metabolism in the medi al temporal lobe. In both men and women, clozapine treatment led to a great er lowering of inferior prefrontal cortex activity than fluphenazine, which was statistically significant in the larger male cohort. Fluphenazine led to higher metabolic rates in the lateral temporal lobe than clozapine did, but the differences between the two neuroleptics were not statistically sig nificant in either group. The greatest differences in the female as compare d to the male responses to fluphenazine and clozapine were in the cingulate and striatum. As compared to controls, the cingulate metabolic rates of wo men were reduced by 9.1% and 11.4% on clozapine and fluphenazine, respectiv ely; whereas, men have a statistically nonsignificant reduction of 0.1% wit h clozapine and a 3.2% increase with fluphenazine. In men, fluphenazine was associated with a much greater elevation in basal ganglia metabolic rates than was clozapine, 23.5% as compared to 3.75%; whereas, in women, basal ga nglia metabolic rates are nearly equally increased by fluphenazine (21.6%) and clozapine (15.1%). [Neuropsychopharmacology 21:632-640, 1999] Published by Elsevier Science Inc.