EFFECTS OF ZOLPIDEM ON LOCAL CEREBRAL GLUCOSE-METABOLISM DURING NON-REM SLEEP IN NORMAL VOLUNTEERS - A POSITRON EMISSION TOMOGRAPHY STUDY

Using positron emission tomography with fluorodeoxyglucose ((18)FDG or FDG), we compared the effects of zolpidem (10 mg), an imidazopyridine hypnotic, which is relatively selective for the BZ(1) or omega recept or and placebo on cerebral glucose metabolism during the first non-REM sleep period of 12 young normal volunteers. Plasma zolpidem pharmacok inetics varied considerably among subjects, and plasma concentrations were lower than usually reported. In general, the effects of zolpidem on local cerebral glucose metabolism varied directly with plasma conce ntrations of zolpidem. Zolpidem induced changes in local cerebral gluc ose metabolism were unevenly distributed throughout the brain and were greater in subcortical areas than lateral cortical areas. Significant negative correlations were found between change in local absolute glu cose metabolic rate (calculated by subtracting individual data on plac ebo nights from that on zolpidem nights) and plasma concentration of z olpidem for the following areas: medial frontal cortex, cingulate gyru s, putamen, thalamus, and hippocampus. The effects of zolpidem on loca l cerebral glucose metabolism were partially but not closely related t o the reported density of BZ(1) receptors.