The long-term clinical benefit and effectiveness of switching to once-daily quetiapine extended release in patients with schizophrenia.

AbstractObjective:To evaluate the long-term clinical benefit and effectiveness of switching to once-daily quetiapine extended release (XR) from an oral antipsychotic in patients with schizophrenia. Reasons for switching included insufficient efficacy, tolerability, and/or non-acceptability. The primary endpoint was the percentage of patients achieving an improvement in Clinical Global Impression – Clinical Benefit (CGI-CB) scale scores.Research design and methods:A 24-week, international, multicentre, open-label, prospective study (www.clinicaltrials.gov: NCT00640601). After a 7–14 day enrolment period (depending whether prior antipsychotic mono- or combination therapy), all patients received quetiapine XR 300 mg once daily (day 1), 600 mg/day (day 2), 600–800 mg/day (day 3) and 400–800 mg/day thereafter, with down-titration and discontinuation of prior antipsychotic by day 4.Results:A total of 62% of patients completed the study and 56.9% (LOCF, ITT) achieved a significant improvement in CGI-CB (95% CI [...