Quetiapine

Abstract

Quetiapine (Seroquel), a dibenzothiazepine derivative, is an atypical antipsychotic with demonstrated efficacy in acute schizophrenia. In short-term, randomised, double-blind trials, it was usually more effective than placebo, and was generally effective against both positive and negative symptoms. Overall, quetiapine (up to 750 mg/day) was at least as effective as chlorpromazine (up to 750 mg/day) and had similar efficacy to haloperidol (up to 16 mg/day) in patients with acute schizophrenia in randomised, double-blind trials; it was at least as effective as haloperidol 20 mg/day in patients with schizophrenia unresponsive or partially responsive to previous antipsychotic treatment. Improvements in overall psychopathology and positive and negative symptoms with quetiapine (up to 800 mg/day) were similar to those with risperidone (up to 8 mg/day) or olanzapine (15 mg/day) [interim analysis]. Efficacy was maintained for at least 52 weeks in open-label follow-up studies in adult and elderly patients. Quetiapine improved cognitive function versus haloperidol, and depressive symptoms and hostility/aggression versus placebo. Quetiapine is well tolerated. It is associated with placebo-level incidence of extrapyramidal symptoms (EPS) across its entire dose range, appears to have a low risk for EPS in vulnerable patient groups (e.g. the elderly, adolescents or patients with organic brain disorders) and has a more favourable EPS profile than risperidone. Irrespective of dose, quetiapine, unlike risperidone and amisulpride, does not elevate plasma prolactin levels compared with placebo, and previously elevated levels may even normalise. Quetiapine appears to have minimal short-term effects on bodyweight and a favourable long-term bodyweight profile. Preliminary studies indicate that there is a high level of patient acceptability and satisfaction with quetiapine. In conclusion, quetiapine has shown efficacy against both positive and negative symptoms of schizophrenia, and has benefits in improving cognitive deficits, affective symptoms and aggression/hostility. The beneficial effects of quetiapine have been maintained for at least 52 weeks. Quetiapine was effective and well tolerated in hard-to-treat patients, and may be of particular use in these individuals. It is at least as effective as standard antipsychotics and appears to have similar efficacy to risperidone and olanzapine. The relative risk/benefit profile of quetiapine compared with other atypical antipsychotics requires further research in head-to-head trials, although quetiapine's relatively benign tolerability profile distinguishes it from other commonly used atypical agents, particularly with respect to bodyweight, EPS and plasma prolactin levels. Overall, quetiapine has an excellent risk/benefit profile and is a suitable first-line option for the treatment of schizophrenia.

Formulation and pharmaceutical development of quetiapine fumarate sustained release matrix tablets using a QbD approach

“…The newly developed agents, called atypical antipsychotics, are successfully used in the treatment of both positive and negative symptoms of schizophrenia and are associated with fewer neurological and endocrine side effects compared to older medications (1). Quetiapine is a recently introduced atypical antipsychotic, which has an excellent risk/benefit ratio and is indicated as the first-line option for the treatment of psychotic disorder manifestations and schizophrenia (2). Quetiapine is available as fumarate salt in immediate as well as in sustained released formulations, the innovative product being Seroquel.…”

Quetiapine Free Base Complexed with Cyclodextrins to Improve Solubility for Parenteral Use

“…Estimation of the Stoichiometric Ratio of Quetiapine/ β-CD Complex To estimate the stoichiometry of the com plex prepared in the phase solubility studies, we measured the 1 HNMR spectrum of the precipitated powder after dissolving the solid complex in DMSOd 6 . 31) Under the present experi mental conditions, information regarding only the stoichiom etry of the complex but not the formation of the complex can be obtained because the βCD molecules should dissociate from the complex.…”

“…Moreover, compared with conven tional antipsychotic drugs, quetiapine is associated with fewer instances of extrapyramidal side effects, agranulocytosis, and hyperprolactinemia. [3][4][5][6][7] Quetiapine is marketed in tablet and fine particle formula tions; fumarate salt ( Fig. 1(I)) is the principal agent.…”

Efficacy and tolerability of quetiapine versus haloperidol in first-episode schizophrenia: a randomized clinical trial

“…Quetiapine is a second-generation antipsychotic that is approved for the treatment of schizophrenia for not only its favorable side-effect profile but also its clinical efficacy [9]. Several short-term studies indicate that quetiapine is more effective than the conventional antipsychotic haloperidol for the treatment of negative schizophrenic symptoms such as withdrawal from social interactions and blunted emotional expression [10].…”