Clinical Benefits of Seroquel XR in Anxiety Disorder

This research will explore whether Quetiapine XR used primarily to treat psychosis may also cover for comorbid anxiety disorder and offer advantages in patients with schizophrenia and comorboid anxiety disorder. Preliminary data on pharmacological properties of Quetiapine and its metabolites and intuitive impression from our clinical experience lead to believe that Seroquel XR use in monotherapy may offer advantages over other antipsychotics in treating co-morbid anxiety disorder in patients suffering from schizophrenia. This open label switch study conducted in a schizophrenic population intends to verify this hypothesis.

This is an open label, non-randomised, single arm phase IIIB study. Patients will be enrolled in this study if their current antipsychotic medication does not provide optimal control of psychopathology symptoms, as judged by the investigator. Therefore, the patients will not be switched from their current effective and well tolerated antipsychotic regimen to the study drug for the sole reason of being enrolled into the study. After enrolment, patients will be switched to Quetiapine XR and followed in an intent-to-treat design over 6 months. Even if a patient should stop for any reason Quetiapine XR or require adding or adjusting an antidepressant for anxiety resistant symptoms, he/she will be assessed for the entire study. Data will be analysed separately. Quetiapine XR will be titrated according to the following pattern: Seroquel XR 300 mg on day 1 and Seroquel XR 600 mg on day 2. On day 3, the dosage could be either maintained at 600 mg/day or continued up to 800 mg/day or if the 600 mg dose is not tolerated, the dose could then be reduced to 400 mg/day. Following this, subjects will be flexibly dosed, according to clinical judgment of the investigator, between 400 mg/day and 800 mg/day with minimum dose adjustments of 200 mg/day. This adjustment can be performed at anytime during the study but should not take place within a week from last cognitive assessment, planned at month 6. An overlap of at least 4 days but not more than 2 weeks with the previous antipsychotic will be allowed with decreasing doses on a two-week period.