The efficacy and tolerability of once-daily extended release quetiapine fumarate in hospitalized patients with acute schizophrenia: a 6-week randomized, double-blind, placebo-controlled study.

Manhattan Psychiatric Center-Nathan Kline Institute for Psychiatric Research, New York University, New York, NY, USA.
Psychopharmacology bulletin (Impact Factor: 0.5). 01/2008; 41(3):11-35.
Source: PubMed

ABSTRACT This study aimed to demonstrate efficacy of once-daily extended release quetiapine fumarate (quetiapine XR) versus placebo in patients with acute schizophrenia.
In this 6-week, randomized, double-blind study (5077IL/0041) patients were randomized to receive quetiapine XR (300, 600, or 800 mg/day), quetiapine fumarate immediate release (quetiapine IR) [300 or 600 mg/day], or placebo. Primary endpoint was change from baseline in the Positive and Negative Syndrome Scale (PANSS) total score at Day 42. Secondary variables included PANSS response rate at Day 42 (>/=30% decrease in PANSS total score from baseline) and Clinical Global Impressions Severity (CGI-S) and Improvement (CGI-I) ratings. Safety assessments included adverse event (AE) reporting and laboratory measures.
Of 532 patients randomized, 222 (41.7%) completed the study. Improvements in PANSS total scores from baseline to Day 42 across treatment groups were: quetiapine XR 300 mg/day -5.01, 600 mg/day -13.01 and 800 mg/day -11.17, quetiapine IR 300 mg/day -9.42 and 600 mg/day -6.97, and placebo -5.19; the difference in change was statistically significant only for quetiapine XR 600 mg/day (p = 0.033). There were no statistically significant differences between active treatment groups and placebo for PANSS response rates. Several post hoc analyses were conducted to explain the study efficacy outcome but these were inconclusive. Quetiapine XR was generally well tolerated with the majority of AEs being mild or moderate in intensity and no unexpected AEs.
Superior efficacy of quetiapine XR versus placebo in patients with schizophrenia was demonstrated for quetiapine XR 600 mg/day. The safety and tolerability profile of quetiapine XR was similar to that of quetiapine IR.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Pharmacokinetic measurement of the psychotropic compound quetiapine and four related metabolites in human plasma was conducted using a sensitive and specific liquid–chromatography tandem mass spectrometry (LC–MS/MS) assay that has been developed and validated for this purpose. The assay employs a single liquid–liquid extraction of quetiapine and its N-desalkyl (norquetiapine, M211,803, M1), 7-hydroxy (M214,227, M2), 7-hydroxy N-desalkyl (M236,303, M3), and sulfoxide (M213,841, M4) metabolites from human plasma, and utilizes dual-column separation, using Luna C18 columns (50 mm × 2.0 mm, 5 μm) and positive ionization tandem MS detection in the multiple reaction monitoring (MRM) mode of the analytes and their respective stable labeled internal standards. The method provides a linear response from a quantitation range of <0.70 ng/ml to at least 500 ng/ml for each analyte using 40 μl of plasma. The applicable range was extended by dilution up to 100-fold with blank matrix. The accuracy and precision for quetiapine were less than 6.0% and 6.4% for quetiapine, respectively. The accuracy (and precision) was less than 9.4% (5.9%) for norquetiapine; 6.4% (6.2%) for M2; and 10.0% (6.4%) for M3; and 8.6% (9.5%) for M4. This methodology enabled the determination of the pharmacokinetics of quetiapine and its metabolites in human plasma, and an example of its application is presented.
    Journal of pharmaceutical and biomedical analysis 04/2010; 51(5-51):1113-1119. DOI:10.1016/j.jpba.2009.11.018 · 2.83 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The atypical antipsychotic, quetiapine, is frequently prescribed on-label and off-label for the treatment of a variety of psychiatric disorders. As quetiapine has variable affinity for dozens of receptors, its clinical effects should also show a large variation as a function of dose and diagnostic category. This study attempts to elucidate the dose-response and comparative efficacy and tolerability (metabolic data) of quetiapine across psychiatric disorders. A systematic search was carried out in the electronic databases, PubMed and EMBASE, using the keywords 'quetiapine' and 'placebo'. Both monotherapy and add-on studies were included. A total of 41 studies were identified. In unipolar and bipolar depression, studies consistently found quetiapine to be effective versus placebo, at doses of approximately 150-300 and 300-600 mg per day, respectively. In bipolar mania, they consistently found quetiapine to be effective at doses of approximately 600 mg per day. In acute exacerbation of schizophrenia, the majority of studies found quetiapine to be effective at doses of approximately 600 mg per day; however, a few large studies found no difference versus placebo. In contrast, studies consistently found quetiapine to be more effective than placebo for stable schizophrenia. In obsessive-compulsive disorder, studies did not consistently find quetiapine to be effective at doses of approximately 300 mg per day. However, studies may have underestimated the efficacy of quetiapine for obsessive-compulsive disorder due to concomitant administration of antidepressants and the utilization of treatment-refractory patients. In generalized anxiety disorder, studies consistently found quetiapine to be effective at doses of approximately 150 mg per day. Finally, analysis of metabolic tolerability data suggests that even low doses of quetiapine may lead to increase in weight and triglycerides across psychiatric disorders. Interestingly, however, quetiapine-induced elevations in low-density lipoprotein and total cholesterol seem to be restricted to schizophrenia patients.
    International clinical psychopharmacology 03/2011; 26(4):183-92. DOI:10.1097/YIC.0b013e3283430a0e · 3.10 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Effective management of schizophrenia remains a significant clinical challenge. While antipsychotic medications have proven efficacy in this disease, there remains an opportunity to further improve symptom control and long-term relapse prevention. Also, a number of factors, including tolerability and complex dosing regimens, can result in nonadherence to medication. Quetiapine is an atypical antipsychotic with proven efficacy and an established tolerability profile in schizophrenia. The once-daily extended-release formulation (quetiapine XR) offers a simplified dosing regimen and titration schedule. Short-term clinical studies have shown that quetiapine XR (400-800 mg/d) is efficacious in the acute treatment of schizophrenia, while a long-term study has shown that quetiapine XR was significantly more effective than placebo at preventing relapse. Furthermore, an investigation in which stable patients switched from the immediate-release formulation (quetiapine IR) to quetiapine XR showed that quetiapine XR is generally well tolerated and has no loss of efficacy compared with quetiapine IR. In patients who experienced insufficient efficacy or poor tolerability on their previous antipsychotic, switching to quetiapine XR significantly improved efficacy compared with the previous treatment. In conclusion, quetiapine XR is an effective and generally well tolerated treatment for schizophrenia. Furthermore, once-daily dosing may improve patient adherence, which may impact positively on patient outcomes.
    Neuropsychiatric Disease and Treatment 09/2011; 7:549-64. DOI:10.2147/NDT.S3380 · 2.15 Impact Factor