Escitalopram in the Treatment of Panic Disorder: A Randomized, Double-Blind, Placebo-Controlled Trial

Background: Escitalopram, the therapeutically active isomer of the racemic selective serotonin reuptake inhibitor antidepressant citalopram, has shown significant anxiolytic effects in placebo-controlled clinical trials of social anxiety disorder, generalized anxiety disorder, and anxiety symptoms associated with major depression. This study evaluated the safety and efficacy of escitalopram in outpatients diagnosed with panic disorder.

Method: Male and female outpatients between 18 and 80 years of age meeting DSM-IV criteria for panic disorder, with or without agoraphobia, were randomly assigned to 10 weeks of double-blind treatment with escitalopram, citalopram, or placebo in a study conducted from September 1999 to July 2001. The primary measure of efficacy was panic attack frequency at week 10 relative to baseline, as assessed by the Modified Sheehan Panic and Anticipatory Anxiety Scale.

Results: A total of 366 subjects (128 escitalopram patients, 119 citalopram patients, and 119 placebo patients) received at least 1 dose of double-blind treatment. The frequency of panic attacks was statistically significantly improved (p = .04), and the increase in percentage of patients with zero panic attacks reached borderline significance (p = .051), in the escitalopram-treated group relative to the placebo-treated group. Both escitalopram and citalopram statistically significantly reduced panic disorder symptoms and severity versus placebo at endpoint (p <= .05), as measured by the Panic and Agoraphobia Scale total score, the Clinical Global Impressions scale, the Patient Global Evaluation, and the Quality of Life Enjoyment and Satisfaction Questionnaire. Treatment with escitalopram was safe and well tolerated, with a similar incidence of the most common adverse events for the escitalopram and placebo groups. The rate of discontinuation for adverse events was 6.3% for escitalopram, 8.4% for citalopram, and 7.6% for placebo.

Conclusion: Escitalopram is efficacious, safe, and well tolerated in the treatment of panic disorder.