Escitalopram and Paroxetine Compared to Placebo in the Treatment of Generalised Anxiety Disorder (GAD)
Baldwin et al., Clinical Neuroscience Division, University of Southampton, UK; 2H.Lundbeck A/S, Copenhagen, Denmark; 3H.Lundbeck A/S, Lysaker, Norway.
The efficacy and tolerability of escitalopram and placebo in the treatment of GAD were compared in a 12-week, randomised, fixed-dose study, using paroxetine as an active reference. Patients with a DSM-IV-TR diagnosis of GAD and aged between 18 and 65 years were randomised to 12 weeks of double-blind treatment with placebo (N=139), escitalopram 5mg/day (N=134), 10mg/day (N=136), or 20mg/day (N=133), or paroxetine 20mg/day (N=140).
Patients were predominantly women (64%) and had a mean age of 41 years. The mean scores at baseline were approximately 27 for the Hamilton Anxiety Scale (HAM-A) total score and 4.6 for the Clinical Global Impressions – Severity score. Approximately 86% of the 682 patients completed 12 weeks of treatment.
Based on the primary efficacy parameter, adjusted mean change from baseline in HAM-A total score at Week 12 (intent-to-treat, last observation carried forward), a significantly better therapeutic effect was seen for both 10mg and 20mg escitalopram than for placebo (p<0.05); escitalopram 10mg was also significantly (p<0.05) more effective than paroxetine 20mg.
The proportion of patients who responded to treatment (Clinical Global Impressions – Improvement [CGI-I] score of 1 or 2) was statistically significantly greater in the escitalopram 10mg (78%) group than in either the placebo (63%) or paroxetine 20mg (66%) groups at Week 12 (p<0.05). Escitalopram 10mg was statistically significantly better than placebo from Week 2 onwards, based on the CGI-I mean scores.
The proportion of patients in remission at Week 12 (HAM-A ≤7) was statistically significantly greater in the escitalopram 5mg (44%), 10mg (48%), and 20mg (43%) groups than in the placebo (30%) group (p<0.05), and significantly greater in the escitalopram 10mg group than in the paroxetine 20mg (33%) group (p<0.05). The remission rate at Week 12 for paroxetine 20mg was not significantly higher than that for placebo.
Overall, the incidence of treatment-emergent adverse events was similar across treatment groups. The treatment-emergent adverse events that were reported with an incidence >10% in one or more of the treatment groups were nausea, fatigue, headache, insomnia, and anorgasmia.
In conclusion, escitalopram (10 and 20 mg/day) was effective and well tolerated in the treatment of GAD for 12 weeks (ref.1).
References:
1. Baldwin et al.