CLINICAL EFFICACY TRIALS
The efficacy of XANAX XR Tablets in the treatment of panic disorder was established in two 6-week, placebo-controlled studies of XANAX XR in patients with panic disorder.
In two 6-week, flexible-dose, placebo-controlled studies in patients meeting DSM-III criteria for panic disorder, patients were treated with XANAX XR in a dose range of 1 to 10 mg/day, on a once-a-day basis. The effectiveness of XANAX XR was assessed on the basis of changes in various measures of panic attack frequency, on various measures of the Clinical Global Impression, and on the Overall Phobia Scale. In all, there were seven primary efficacy measures in these studies, and XANAX XR was superior to placebo on all seven outcomes in both studies. The mean dose of XANAX XR at the last treatment visit was 4.2 mg/day in the first study and 4.6 mg/day in the second.
In addition, there were two 8-week, fixed-dose, placebo-controlled studies of XANAX XR in patients with panic disorder, involving fixed XANAX XR doses of 4 and 6 mg/day, on a once-a-day basis, that did not show a benefit for either dose of XANAX XR.
The longer-term efficacy of XANAX XR in panic disorder has not been systematically evaluated.
Analyses of the relationship between treatment outcome and gender did not suggest any differential responsiveness on the basis of gender.