[Administration of once-daily extended release quetiapine in schizophrenic disorders].

This article reviews the published clinical data on schizophrenic patients managed with the new formulation of quetiapine, the once-daily extended release quetiapine fumarate (quetiapine XR). Quetiapine XR has been developed to reduce the frequency of quetiapine dosing by introducing once-daily administration and to simplify the treatment initiation schedule. Quetiapine XR (400 to 800 mg/day) was effective versus placebo across a broad range of symptom domains in acute schizophrenia and was as well tolerated as the immediate release (IR) formulation. Rapid dose escalation of quetiapine XR (300 mg on day 1,600 mg on day 2, and 800 mg on day 3) was also well tolerated, with a therapeutically effective dose reached by day 2. Clinically stable patients with schizophrenia receiving quetiapine IR (400-800 mg/day) can be switched to an equivalent once-daily dose of quetiapine XR (400-800 mg/day once-daily) without clinical deterioration or compromise in tolerability. Evidence from a clinical trial has shown that patients with schizophrenia who had a history of unsatisfactory treatment (tolerability or efficacy) on typical or atypical antipsychotic experienced improved efficacy and clinical benefit when switched to quetiapine XR. Once-daily quetiapine XR (400-800 mg/nap) was effective compared with placebo in preventing relapse in patients with clinically stable schizophrenia, and was well tolerated during long-term use. Patients could be switched from their ongoing antipsychotic to quetiapine XR within 4 days without compromising efficacy, enabling a dose of 600 mg/day and 800 mg/day to be reached by Day 2 and Day 3 respectively. This new, once-daily formulation of quetiapine offers psychiatrists and patients valuable new treatment options for the short and long-term treatment of schizophrenia.