Double-blind, randomized study of extended release quetiapine fumarate (quetiapine XR) monotherapy in older patients with generalized anxiety disorder

Objective: The objective of the study was to evaluate once-daily extended release quetiapine fumarate (quetiapine XR) monotherapy in older patients with generalized anxiety disorder (GAD).

Methods: An 11-week (9-week treatment; 2-week posttreatment), randomized, double-blind, placebo-controlled study (D1448C00015) of flexibly-dosed quetiapine XR (50-300 mg/day) or placebo conducted at 47 sites (Estonia, Poland, Russia, Ukraine, and USA) between September 2006 and April 2008. Patients (≥66 years) with DSM-IV diagnosis of GAD, Hamilton Anxiety Rating Scale (HAM-A) total score of ≥20 with item 1 (anxious mood) and 2 (tension) scores of ≥2, Clinical Global Impressions-Severity of Illness (CGI-S) score of ≥4, and Montgomery Åsberg Depression Rating Scale (MADRS) total score of ≤16 were eligible for inclusion. Primary endpoint: week 9 change from randomization in HAM-A total score.

Results: Patients were randomized to quetiapine XR (n = 223) or placebo (n = 227). At week 9, quetiapine XR significantly reduced HAM-A total score versus placebo (least squares mean -14.97 versus -7.21; p < 0.001); symptom improvement with quetiapine XR versus placebo was significant at week 1 (p < 0.001). At week 9, quetiapine XR demonstrated significant benefits over placebo for HAM-A response and remission rates, HAM-A psychic and somatic cluster, MADRS total, CGI-S, Pittsburgh Sleep Quality Index global, pain visual analog scale, and Quality of Life, Enjoyment and Satisfaction Questionnaire short form % maximum total scores and Clinical Global Impressions-Improvement (% patients with a score of 1/2) (all p < 0.001). Adverse events (>5% in either treatment group) included somnolence, dry mouth, dizziness, headache, and nausea.

Conclusions: Quetiapine XR (50-300 mg/day) monotherapy is effective in the short term in improving symptoms of anxiety in older patients with GAD, with symptom improvement seen as early as week 1. Tolerability findings were generally consistent with the known profile of quetiapine.