A double-blind comparison of risperidone, quetiapine and placebo in patients with schizophrenia experiencing an acute exacerbation requiring hospitalization

Randomized, Double-Blind, Placebo-Controlled Study of Paliperidone Extended-Release and Quetiapine in Inpatients With Recently Exacerbated Schizophrenia

“…This can be a particular issue in hospitalized patients owing to the confounding effect of a response due to increased care. Indeed, a high placebo response was observed in this study, consistent with findings in a previous study in a similar population (9). The placebo arm helped to control for this factor and aided in the interpretation of findings.…”

“…Based on previous studies of paliperidone extended-release and quetiapine (4)(5)(6)9), a sample of 134 patients in each activetreatment group was anticipated to have ≥90% power to detect an effect size of 0.4 in PANSS total change at day 14, with an assumption of equal variance at a 0.05 two-sided significance level. With a 2:2:1 randomization ratio for the paliperidone extendedrelease, quetiapine, and placebo groups, respectively, an estimated total of 335 subjects was required; assuming 15% attrition at day 14, the trial required a total of 395 patients in the randomization process.…”

“…Paliperidone extended-release is an osmotically released oral formulation that minimizes peak-to-trough fluctuation and allows initiation at a once-daily therapeutic dose (8) without the need for dose titration. The parent molecule, risperidone, which may necessitate titration and twicedaily dosing, has shown greater efficacy than quetiapine (another atypical antipsychotic) and placebo in a study of acutely ill hospitalized patients (9). In contrast to risperidone and other antipsychotics, paliperidone extendedrelease undergoes limited hepatic metabolism, with minimal involvement of the cytochrome P450 2D6 and 3A4 pathways and a low likelihood of hepatically mediated drug-drug interactions in patients receiving combination therapy (10,11).…”

How effective are second-generation antipsychotic drugs? A meta-analysis of placebo-controlled trials

“…29 Owing to space limitations, we do not show the results here, but any result that deviated to an important extent from the primary analysis will be mentioned.…”

Real-world use of quetiapine in early psychosis: An acute inpatient and community follow-up effectiveness study

“…Appropriate quetiapine dosing in adolescent [19] and early psychosis [20] patients are not adequately established, though a dose-finding study in the latter group has recently been reported [28]. Contrary to the results of the pivotal randomised controlled trials (RCT) supporting quetiapine's efficacy in acute psychosis, a recent international RCT found it no more effective than placebo [21].…”