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. 2011:7:549-64.
doi: 10.2147/NDT.S3380. Epub 2011 Sep 21.

The management of schizophrenia: focus on extended-release quetiapine fumarate

Joseph Peuskens  1
Affiliations

The management of schizophrenia: focus on extended-release quetiapine fumarate

Joseph Peuskens. Neuropsychiatr Dis Treat. 2011.

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.

Keywords: adherence; adverse events; atypical antipsychotics.

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Figures

Figure 1
Figure 1
Reported barriers to medication adherence in patients with schizophrenia. Hudson TJ, Owen RR, Thrush CR, et al. A pilot study of barriers to medication adherence in schizophrenia. J Clin Psychiatry. 2004;65(2):211–216. Copyright © 2004 Physicians Postgraduate Press. Reprinted by permission.
Figure 2
Figure 2
Mean plasma quetiapine concentrations (and standard errors of the mean) measured over a 24-hour dosing interval for quetiapine IR and quetiapine XR. Reproduced with permission. Figueroa C, Brecher M, Hamer-Maansson JE, Winter H. Pharmacokinetic profiles of extended release quetiapine fumarate compared with quetiapine immediate release. Prog Neuropsychopharmacol Biol Psychiatry. 2009;33(2):199–204. Abbreviations: IR, immediate release; XR, extended release.
Figure 3
Figure 3
Change in PANSS total score from baseline to week 6 (MITT, LOCF). Notes: *P < 0.05; **P < 0.01; ***P < 0.001 versus placebo. Kahn RS, Schulz SC, Palazov VD, et al. Efficacy and tolerability of once-daily extended release quetiapine fumarate in acute schizophrenia: a randomized, double-blind, placebo-controlled study. J Clin Psychiatry. 2007;68(6):832–842. Copyright © 2007 Physicians Postgraduate Press. Reprinted by permission. Abbreviations: IR, immediate release; LOCF, last observation carried forward; MITT, modified intention-to-treat; PANSS, Positive and Negative Syndrome Scale; XR, extended release.
Figure 4
Figure 4
Percentage of patients achieving clinical benefit after switching to quetiapine XR (ITT population). Note: ***P < 0.001 based on null hypothesis that ≤ 50% of patients would achieve an improvement. Reproduced with kind permission. Ganesan S, Agambaram V, Randeree F, Eggens I, Huizar K, Meulien D. Switching from other antipsychotics to once-daily extended release quetiapine fumarate in patients with schizophrenia. Curr Med Res Opin. 2008;24(1):21–32. Abbreviations: ITT, intention-to-treat; XR, extended release.
Figure 5
Figure 5
Proportion of patients remaining relapse-free (survival distribution function) over time with quetiapine XR or placebo in patients with schizophrenia (interim ITT population). The final steps after 6 months in the Kaplan-Meier curves are due to a late relapse of a single patient on quetiapine XR at a time when only 2 patients were at risk and to a late relapse of a single patient in the placebo group at a time when no other patient receiving placebo was at risk. Thus, after 6 months’ exposure, Kaplan-Meier curves depend on single events and do not give reliable estimates of the percentage of relapse-free patients. Peuskens J et al. Prevention of schizophrenia relapse with extended release quetiapine fumarate dosed once daily: a randomized, placebo-controlled trial in clinically stable patients. Psychiatry (Edgemont). 2007;4(11):34–50. Reproduced with permission from Psychiatry (Edgemont). Abbreviations: ITT, intention-to-treat; XR, extended release.
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References

    1. Weiden PJ, Preskorn SH, Fahnestock PA, Carpenter D, Ross R, Docherty JP. Translating the psychopharmacology of antipsychotics to individualized treatment for severe mental illness: a Roadmap. J Clin Psychiatry. 2007;68(Suppl 7):1–48. - PubMed
    1. Lacro JP, Dunn LB, Dolder CR, Leckband SG, Jeste DV. Prevalence of and risk factors for medication nonadherence in patients with schizophrenia: a comprehensive review of recent literature. J Clin Psychiatry. 2002;63(10):892–909. - PubMed
    1. Valenstein M, Ganoczy D, McCarthy JF, Myra KH, Lee TA, Blow FC. Antipsychotic adherence over time among patients receiving treatment for schizophrenia: a retrospective review. J Clin Psychiatry. 2006;67(10):1542–1550. - PubMed
    1. Velligan DI, Lam F, Ereshefsky L, Miller AL. Psychopharmacology: perspectives on medication adherence and atypical antipsychotic medications. Psychiatr Serv. 2003;54(5):665–667. - PubMed
    1. Byerly MJ, Nakonezny PA, Lescouflair E. Antipsychotic medication adherence in schizophrenia. Psychiatr Clin North Am. 2007;30(3):437–452. - PubMed