A Double-Blind Comparison of Escitalopram and Paroxetine in the Long-Term Treatment of Generalized Anxiety Disorder

Background. This study compared the efficacy and tolerability of escitalopram, a newer SSRI, with paroxetine in the treatment of generalized anxiety disorder (GAD). Methods. Patients with DSM-IV-defined GAD were randomized to receive 24 weeks of double-blind flexible-dose treatment with either escitalopram (10–20 mg/day) or paroxetine (20–50 mg/day), followed by a 2-week, double-blind, down-titration period. Mean change from baseline to endpoint (LOCF) in Hamilton Anxiety Scale (HAMA) scores was the primary efficacy
variable.

Results. Mean baseline HAMA scores for the escitalopram (N=60) and paroxetine (N=61) groups were 23.7 and 23.4, respectively. After 24 weeks of treatment, mean changes in HAMA scores were −15.3 and −13.3 for escitalopram and paroxetine, respectively (p=0.13). Significantly fewer patients withdrew from escitalopram than paroxetine treatment due
to adverse events (6.6% vs. 22.6%; p=0.02). The frequency of treatment-emergent adverse events was higher with paroxetine vs. escitalopram: overall (88.7% vs. 77.0%), insomnia (25.8% vs. 14.8%), constipation (14.5% vs. 1.6%), ejaculation disorder (30.0% vs. 14.8%), anorgasmia (26.2% vs. 5.9%), and decreased libido (22.6% vs. 4.9%). Conversely, diarrhea and upper respiratory tract infection were reported more with escitalopram than paroxetine (21.3% vs. 8.1%, and 14.8% vs. 4.8%, respectively).

Conclusions. These results support the use of escitalopram as a first-line treatment for GAD.

Reference: Bielski et al  Ann Clin Psychiatry 2005; 17: 65–69