Taku Nakagami

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AIMS An in vitro study has suggested that risperidone is a substrate of P-glycoprotein, which is coded by MDR-1 gene. Thus, we studied the effects of major polymorphisms of the MDR-1 gene on plasma drug concentrations. METHODS Subjects were 85 schizophrenic patients receiving 3 mg twice daily of risperidone. Sample collections were conducted 12 h after(More)
The authors investigated steady-state pharmacokinetics of perospirone and its active metabolite hydroxyperospirone (ID-15036) and its prolactin response in 10 schizophrenic patients receiving 16 mg twice daily. Plasma concentrations of perospirone, hydroxyperospirone, and prolactin were monitored just before and up to 12 hours after the dosing. Thereafter,(More)
AIMS In an Asian population, the criteria for metabolic syndrome (MetS) are different from those for Western populations. The aim of this study was to assess the MetS prevalence among patients with schizophrenia or schizoaffective disorder in Japan. METHODS We recruited patients (n=1186), aged 54.8±14.8 (mean±SD) years old with the DSM-IV diagnosis of(More)
Various studies have revealed that sexual dysfunction is prevalent in schizophrenia patients treated with either first- or second-generation antipsychotics. Although sexual dysfunction may have a negative impact on adherence to treatment, no reports have studied sexual dysfunction in schizophrenia patients compared with healthy controls in Asian(More)
Smoking prevalence for schizophrenic patients is higher than for the general population. Inter-individual variability in hyperprolactinemia induced antipsychotics particularly risperidone can be explained by smoking status to some extent. We therefore studied the effects of smoking status on the plasma concentration of prolactin. Subjects included 154(More)
Polymorphic enzyme cytochrome P450 (CYP) 2C19 is expressed not only in the liver but also in the brain and mediates the biotransformation of 5-hydroxytriptamine (5-HT). We investigated possible association between genetic polymorphism of CYP2C19 and individual personality traits, possibly influenced by neurotransmitters. Mentally and physically healthy(More)
BACKGROUND This study investigated the possible association between common and potentially functional polymorphisms of antioxidant enzymes and metabolic abnormalities in patients with schizophrenia. METHODS The possible associations of the glutathione S-transferase (GST) M1 null and GSTT1 null genotypes, and the superoxide dismutase 2 (SOD2) Val16Ala(More)
AIMS A tree-drawing test acts as both a projective psychological examination as well as a supplementary psychodiagnostic tool. There is little information relating the characteristics of schizophrenia and the tree-drawing test. The present study compared the structural and morphological differences in the results of the tree-drawing test between(More)
AIMS Omeprazole is mainly metabolized by the polymorphic cytochrome P450 (CYP) 2C19. The inhibitory effect of fluvoxamine, an inhibitor of CYP2C19 as well as CYP1A2, on the metabolism of omeprazole was compared between different genotypes for CYP2C19. METHODS Eighteen volunteers, of whom six were homozygous extensive metabolizers (EMs), six were(More)