Compare the Effect on Cognitive Functioning of Two Formulations of Seroquel, Seroquel XR and IR in Patients With Stable Schizophrenia
Condition: Schizophrenia
MeSH terms: Schizophrenia
Intervention: Seroquel XR- quetiapine fumarate extended release; Seroquel IR - quetiapine fumarate; Placebo matching Seroquel XR; Placebo matching Seroquel IR
Intervention description: Seroquel XR dose 400-700 mg (in tablet form). The investigator established the dosing schedule for each patient depending on the patient's dose when entering the study. The patients continued on the same dose during the study as they had prior to enrolment. Dose taken once a day for 10-16 days.; Seroquel IR dose 400-700 mg (in tablet form). The investigator established the dosing schedule for each patient depending on the patient's dose when entering the study. The patients continued on the same dose during the study as they had prior to enrolment. Dose taken twice a day for 10-16 days.; Placebo matching Seroquel XR dose 400-700 mg (in tablet form). Dose taken once a day for 10-16 days.; Placebo matching Seroquel IR dose 400-700 mg (in tablet form). Dose taken twice a day for 10-16 days.
Intervention MeSH terms: Quetiapine Fumarate
Phase: Phase 4
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Enrollment: 75.0
Sex: All
Minimum age: 18 Years
Maximum age: 50 Years
Healthy volunteers: No
Keywords: Stable schizophrenia; cognitive functioning

Summary:

      This will be a phase IV 20 -32 day prospective, double blind, double-dummy, randomised
      crossover study that will evaluate the effect of quetiapine XR and quetiapine IR on cognitive
      performance in patients with schizophrenia stabilized on a single antipsychotic medication.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Provision of written informed consent prior to any study specific procedures

          -  Documented clinical diagnosis of schizophrenia, paranoid type, for at least 2 years
             before randomisation meeting the Diagnostic and Statistical Manual of Mental
             Disorders, 4th Edition (DSM-IV, American Psychiatric Association 2000) criteria of
             schizophrenia (DSM-IV codes 295.3) confirmed by MINI version 5.0

          -  Outpatient status at enrolment

          -  Dose of quetiapine IR or quetiapine XR unchanged during the last 56 days before
             randomisation

        Exclusion Criteria:

          -  Diagnosis of any DSM-IV Axis I disorder other than those included in inclusion
             criteria above within 6 months before randomisation (e.g., alcohol dependence or
             psychoactive substance dependence not in full remission, concurrent organic mental
             disorder, or mental retardation [axis II diagnosis]) of a degree that may interfere
             with the patient's ability to co-operate.

          -  Previous stable use of high dosage of benzodiazepines during one year or more

          -  Significant neurological medical history (complicated head trauma as judged by the
             investigator, epilepsy, meningo-encephalitis)

          -  Use of the following medication:

          -  other antipsychotic drug than quetiapine within 28 days prior to randomisation

          -  a depot antipsychotic injection within two dosing intervals (for the depot) before
             randomisation (Visit 2)

          -  other psychoactive drugs within 14 days prior to randomisation (hypnotic or anxiolytic
             drugs, other than those allowed)

          -  Use of concomitant therapy likely to affect cognition, Medication prohibited 28 days
             prior to randomisation: benzodiazepines, amphetamines, reboxitin, atomoxinetine,
             buspiron, donepezil, duloxetine, galantamine, ginko biloba, memantine,
             methylphenidate, modafinil, rivastigmine, tacrine, smoking cessation therapy
             varencicline and any dosage form of nicotine replacement therapy. Medication
             prohibited 14 days prior to randomisation: irreversible monoamine oxidase inhibitors
             (MAOI), tricyclic antidepressants (TCA), biperiden, antoicholinergic agents (even if
             the indications are extra pyramidal symptoms or urinary symptoms)