Effects of the GABA-reuptake inhibitor tiagabine on panic and anxiety in patients with panic disorder.

INTRODUCTION: There is evidence that a decreased GABAergic tone plays a role in the pathophysiology of panic disorder (PD). Selective GABAergic treatment has been suggested as a new therapeutic strategy in PD. In this pilot-study anxiolytic effects of the GABA reuptake inhibitor tiagabine (TGB) were investigated in PD.

METHODS: A total of 19 patients were treated with TGB (n=10) or placebo (n=9) for 4 weeks. PAS, HAM-A, and CGI ratings were administered every week. To further assess specific antipanic activity, panic challenges with CCK-4 were carried out in single subjects.

RESULTS: Although there was a significant reduction of clinical rating scores over time, no differences were detected between the groups. However, during challenge experiments TGB treated subjects showed decreased sensitivity to CCK-4.

DISCUSSION: Whereas tiagabine did not show beneficial effects on clinical symptoms in PD compared to placebo, results of challenge experiments suggest effects of TGB on sensitivity to experimentally induced panic.