Potential effectiveness and safety of olanzapine in refractory panic disorder.

Panic disorder is a common and disabling psychiatric disorder. Despite treatment advances, refractory panic disorder requires novel interventions. One such pharmacologic intervention with theoretical and case study support includes olanzapine, a thienobenzodiazepine medication currently approved for schizophrenia in the United States. Ten people with refractory DSM-IV diagnosed panic disorder completed an 8-week, open-label, flexible-dose clinical trial. Baseline, in-treatment, and end-of-treatment data for panic attacks, anticipatory anxiety, phobic avoidance, and impairment were collected. Data were analyzed using SPSS software. Refractory panic disorder patients required a wide dose range averaging 12.3 mg/day of olanzapine to significantly improve or ablate panic attacks. On the average, number of attacks decreased from 6.1/week at baseline to 1.1/week at the end of treatment, and anticipatory anxiety from 32% of the day to 8% of the day. At treatment end, 5 of 10 participants (50%) were panic free, 4 (40%) had one attack in the previous week, 1 (10%) had seven attacks in the previous week, and 6 of 10 participants (60%) were anticipatory anxiety free. There were also statistically and clinically significant improvements in impairment over the course of the trial. There were no significant changes in vital signs, emergent side effects, or average weight, although 6 of 10 people did gain weight. Olanzapine is potentially effective and safe in panic disorder. Due to study limitations, further clinical trials are needed to demonstrate effectiveness.