Switching from imipramine to sertraline in panic disorder

There are no systematic switching studies of antidepressants in the treatment of panic disorder. The present pilot study examined the usefulness of switching from imipramine to sertraline in 18 patients diagnosed with panic disorder with agoraphobia.

15 patients who had had an unsatisfactory outcome in a 24-week, open, weight-adjusted fixed-dose imipramine treatment study and 3 patients who had had a very satisfactory outcome but had subsequently relapsed following imipramine discontinuation were systematically switched to protocolized, 24-week open treatment with sertraline, 50-100 mg/day. Uniform measures of efficacy and side effects were used throughout the study. The net benefit obtained from the switch was assessed using an operationalized outcome grade ranging from 0-2, where 0 = inadequate duration of trial (dropouts) or non-response, 1 = partial response or full responders with side effects necessitating a change in treatment, and 2 = full response without complications.

Based on paired t-tests, following the switch from imipramine to sertraline, a significant improvement was seen on phobic and panic symptomatologies, side effects, and overall outcome grade (from 0.67 [+/- 0.77] to 1.17 [+/- 0.92], p < or = 0.05]. Of the 18 patients who were switched to sertraline treatment, 9 (50%) clearly gained from the switch, 6 (33.3%) had an outcome similar to that achieved with imipramine, and 3 (16.7%) had a worse outcome following the switch. Of the 9 patients who failed to respond to or were unable to tolerate treatment with imipraminel (rating of 0), 3 patients (33.3%) achieved full and 2 patients (22.2%) achieved partial response after switching to sertraline.

The findings in this study suggest that switching between antidepressants with established antipanic efficacy may be an effective strategy in the management of patients with panic disorder who have had an unsatisfactory outcome with the first antidepressant tried.