Two SSRIs useful in long-term generalized anxiety: efficacy was similar, but a direct comparison showed that escitalopram was better tolerated than paroxetine.
Selective serotonin reuptake inhibitors (SSRIs) are increasingly being prescribed for generalized anxiety disorder, according to Dr. Bielski, a researcher at Summit Research Network in Okemos, Mich., which conducts clinical trials for pharmaceutical companies, including Forest Labs Inc., the maker of escitalopram (Lexapro).
In a rare direct comparison, he and his colleagues assessed the efficacy and tolerability of escitalopram and paroxetine (Paxil), two agents approved by the Food and Drug Administration for treating generalized anxiety disorder. (Extended-release venlafaxine is also FDA approved for this condition.)
All participants met the DSM-IV definition for generalized anxiety disorder: a baseline score on the Hamilton Anxiety Scale of 18 or more. The mean age of the participants was 37 years.
There were 60 patients randomized to escitalopram and 61 to paroxetine. The study began with a week of single-blind placebo treatment, followed by 24 weeks of double-blind, flexible-dose treatment with either 10-20 mg/day of escitalopram or 20-50 mg/day of paroxetine. After an additional 2 weeks to titrate participants down, their Hamilton anxiety scores were compared for mean change from baseline.
Efficacy was similar; both agents improved anxiety symptoms. The mean baseline Hamilton anxiety score was 23.7 in the escitalopram group and 23.4 in the paroxetine group. At the end of the study, the mean reduction in scores was 15.3 in the escitalopram group and 13.3 in the paroxetine group.
"The SSRIs are a family of antidepressants that are really revolutionary. They are so much better tolerated than their predecessors," said Dr. Bielski.
A representative of GlaxoSmithKline, the maker of paroxetine, declined to comment on the findings.
There were differences in adverse effects between the two treatment groups. The researchers noted the most frequent adverse events in 10% or more of patients. In the escitalopram group, diarrhea (21%), upper respiratory tract infection (15%), and fatigue (12%) were most common. In the paroxetine group, ejaculation disorder (30%), anorgasmia (26%), and insomnia (26%) were most common.
There was a statistically significant difference in the numbers of patients who withdrew from the study because of adverse events, Dr. Bielski said.
A total of 6.6% withdrew from the escitalopram group, compared with 22.6% of the paroxetine group.
Dr. Bielski said that Forest Labs Inc. is considering conducting future studies to assess these findings.
Most Common Adverse Effects ESCITALOPRAM GROUP Diarrhea 21% Upper respiratory infection 15% Fatigue 12% PAROXETINE GROUP Ejaculation disorder 30% Anorgasmia 26% Insomnia 26% Note: Table made from bar graph.
BY DAMIAN MCNAMARA
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|Title Annotation:||Psychiatry; Selective serotonin reuptake inhibitors|
|Publication:||Internal Medicine News|
|Date:||Nov 1, 2004|
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