desmethylolanzapine and Schizophrenia

This therapeutic drug monitoring (TDM) study aimed to determine the role of olanzapine (OLZ) and N-desmethyl-OLZ (DMO) levels in the therapeutic efficacy of OLZ in patients with schizophrenia.. Plasma concentrations of OLZ (COLZ) and DMO (CDMO) in schizophrenic patients 12 hours post-dose were assessed. The correlations of COLZ and CDMO with the various scores of the Positive and Negative Syndrome Scale (PANSS) were evaluated. A receiver operating characteristic curve (ROC) was utilized to identify the threshold COLZ and COLZ/CDMO ratio for maintenance of satisfactory efficacy.. A total of 151 samples from patients with schizophrenia were analyzed for individual COLZ and CDMO levels. The mean COLZ and CDMO levels were 37.0 ± 25.6 and 6.9 ± 4.7 ng/mL, respectively, and COLZ was ~50% higher in female or nonsmokers (p<0.01). In all patients, the daily dose of OLZ was positively correlated with COLZ and CDMO. Linear relationships between COLZ and OLZ dose were observed in both nonsmokers and smokers (rs = 0.306, 0.426, p<0.01), although CDMO was only correlated with OLZ dose in smokers (rs = 0.485, p<0.01) and not nonsmokers. In all patients, COLZ was marginally negatively correlated with the total PANSS score. The total PANSS score was significantly negatively correlated with the COLZ/CDMO ratio (p<0.005), except in smokers. The ROC analysis identified a COLZ/CDMO ratio ≥2.99 or COLZ ≥22.77 ng/mL as a predictor of maintenance of an at least mildly ill status (PANSS score ≤58) of schizophrenia in all patients.. A significantly negative correlation between the steady-state COLZ/CDMO ratio and total PANSS score was observed in Taiwanese schizophrenic patients. TDM of both OLZ and DMO levels could assist clinical practice when individualizing OLZ dosage adjustments for patients with schizophrenia.

Topics: Adult; Antipsychotic Agents; Benzodiazepines; Drug Monitoring; Female; Humans; Male; Middle Aged; Olanzapine; Pirenzepine; Psychiatric Status Rating Scales; ROC Curve; Schizophrenia

Olanzapine (OLZ) is one of the most prescribed atypical antipsychotic drugs but its use is associated with unfavorable metabolic abnormalities. N-desmethyl-olanzapine (DMO), one of the OLZ metabolites by CYP1A2, has been reported to have a normalizing action on metabolic abnormalities, but this remains unclear. Our aim was to explore the correlation between the concentrations of OLZ or DMO with various metabolic parameters in schizophrenic patients.. The chromatographic analysis was carried out with a solvent delivery system coupled to a Coulochem III coulometric detector to determine OLZ and DMO simultaneously in OLZ-treated patients. The correlation between the concentration of OLZ or DMO and the metabolic parameters was analyzed by the Spearman rank order correlation method (r s).. The established analytical method met proper standards for accuracy and reliability and the lower limitation of quantification for each injection of DMO or OLZ was 0.02 ng. The method was successfully used for the analysis of samples from nonsmoking patients (n = 48) treated with OLZ in the dosage range of 5-20 mg per day. There was no correlation between OLZ concentrations and tested metabolic parameters. DMO concentrations were negatively correlated with glucose (r s = -0.45) and DMO concentrations normalized by doses were also negatively correlated with insulin levels (r s = -0.39); however, there was a marginally positive correlation between DMO and homocysteine levels (r s = +0.38).. The observed negative correlations between levels of DMO and glucose or insulin suggest a metabolic normalization role for DMO regardless of its positive correlation with a known cardiovascular risk factor, homocysteine. Additional studies of the mechanisms underlying DMO's metabolic effects are warranted.

Topics: Adult; Antipsychotic Agents; Benzodiazepines; Chromatography, High Pressure Liquid; Female; Humans; Male; Middle Aged; Olanzapine; Pirenzepine; Reproducibility of Results; Schizophrenia; Young Adult

The aim of this study was to assess dose-related steady-state serum concentrations of olanzapine (OLZ) and its metabolites N-desmethyl OLZ (DMO) and 2-hydroxymethyl OLZ (2-OH-OLZ) (assessed by high-performance liquid chromatography) in 122 child and adolescent psychiatric patients (age 16.9 +/- 2.2, range, 10-21 years; 74 males, 48 females) with a variety of diagnoses: schizophrenia group (n = 80); nonschizophrenia group (n = 29); anorexia nervosa (AN) group (n = 13). Median OLZ serum concentrations were 32.7 (range, 1-118; all patients), 37.7 (2-115; schizophrenia group), and 18.7 (1-63, AN group) ng/mL. The median OLZ concentration-to-dose (C/D) ratio (n = 122) was 2.6, with 90% of the distribution between 0.8 and 5.5 (ng/mL)/(mg/d). OLZ concentration was significantly correlated with DMO (r = 0.567; P < 0.0005) but not with 2-OH-OLZ (r = 0.122; P = 0.188). Daily OLZ dose was correlated with OLZ concentration in all (r = 0.684; P < 0.0005), schizophrenic (r = 0.542; P < 0.0005), and AN (r = 0.805; P = 0.001) patients, respectively. Patients aged less than 16 years displayed similar C/D for OLZ (P = 0.58) but higher C/D for DMO (P = 0.003) than those 16 years or older. AN patients received lower median OLZ doses (7.5; 5-15 mg) than schizophrenic patients (12.5; 2.5-40 mg), even after correcting for body mass index (P = 0.02). OLZ dose did not differ (P = 0.088) between smokers and nonsmokers, but smokers showed lower C/D for OLZ than nonsmokers (P = 0.008). C/D for OLZ was 38% higher (P = 0.041) under comedication with selective serotonin reuptake inhibitors when compared with OLZ monotherapy. Multiple linear regression analysis revealed that 46% of the variation of OLZ concentration can be explained by dose, diagnosis, age, sex, smoking, and comedication. The data are compared with the literature, and the relevance of therapeutic antipsychotic drug monitoring in previously sparsely investigated subgroups, such as children and adolescents or patients with AN, is emphasized.

Topics: Adolescent; Adult; Age Factors; Anorexia Nervosa; Antipsychotic Agents; Benzodiazepines; Child; Drug Combinations; Female; Humans; Male; Olanzapine; Pirenzepine; Schizophrenia; Sex Factors; Smoking

A high-performance liquid chromatographic method with amperometric detection for the analysis of the novel antipsychotic drug olanzapine and its metabolite desmethylolanzapine in human plasma has been developed. The analysis was carried out on a reversed-phase column (C8, 150 x 4.6 mm I.D., 5 microm) using acetonitrile-phosphate buffer, pH 3.8, as the mobile phase. The detection voltage was + 800 mV and the cell and column temperature was 30 degrees C. The flow-rate was 1.2 ml min(-1). Linear responses were obtained between 5 and 150 ng ml(-1), with repeatability <3.3%. A careful pretreatment of the biological samples was implemented by means of solid-phase extraction (SPE) on C8 cartridges. The method requires 500 microl of plasma for one complete analysis. Absolute recovery exceeded 97% for both olanzapine and desmethylolanzapine, and the detection limit was 1 ng ml(-1) for both analytes. Repeatability, intermediate precision and accuracy were satisfactory. This sensitive and selective method has been successfully applied to therapeutic drug monitoring in schizophrenic patients treated with Zyprexa tablets.

Topics: Antipsychotic Agents; Benzodiazepines; Chromatography, High Pressure Liquid; Electrochemistry; Humans; Olanzapine; Pirenzepine; Reproducibility of Results; Schizophrenia; Sensitivity and Specificity