The extended-release formulation of quetiapine fumarate (quetiapine XR) adjunctive treatment in partially responsive generalized anxiety disorder (GAD): An open label naturalistic study.

AIMS: To assess the effect of adjunctive treatment with extended-release formulation of quetiapine fumarate (quetiapine XR) to other antidepressants in the treatment of partially responsive, poorly functioning patients with generalized anxiety disorder was assessed.
MATERIALS AND METHODS: Twenty four consenting adult outpatients with confirmed DSM-IV diagnosis of generalized disorder were identified. All patients failed at least one 8-week treatment trial with SSRI or SNRI antidepressant. All were treated with quetiapine XR as an add on treatment to citalopram or vanlafaxine antidepressant for at least 12 weeks. The primary efficacy measure was the Clinical Global Impression Scale (CGI-S). Other scales included; the Hamilton Anxiety Scale (HAM-A) scale, Sheehan Disability Scale, and the Abnormal Involuntary Movement Scale (AIMS). Baseline measures prior to adding quetiapine XR were compared to those at 4, 8 and 12 weeks with the adjunctive treatment.
RESULTS: Twenty three patients completed the trial. There was significant rapid resolution of the anxiety symptoms in all effectiveness measures, including the symptoms of anxiety as shown by changes from baseline in HAM-A, and CGI at four weeks. Improvement was maintained to week twelve. Impairments in work, social, and home responsibilities were also reduced significantly, and there were no significant changes in weight at 12 weeks. Patients tolerated the adjunctive treatment well.
CONCLUSION: Quetiapine XR may have anxiolytic properties and could be used effectively as adjunctive treatment with SSRIs in GAD patients with partial response to SSRs or SNRISs. However double blind randomized trials are needed to support these results.