By Karla Gale
NEW YORK (Reuters Health) – Paroxetine, fluoxetine, and sertraline are comparable in reducing depressive symptoms among patients treated in primary care settings, according to the results of A Randomized Trial Investigating SSRI Treatment (ARTIST).
However, many patients need to be switched to a different antidepressant if they do not adequately respond to or tolerate the initial selective serotonin reuptake inhibitor (SSRI), investigators report in December 19th issue of The Journal of the American Medical Association.
Dr. Kurt Kroenke, of the Indiana University School of Medicine in Indianapolis, and associates evaluated patients with clinical depression warranting treatment, as determined by the participating physician. The patients and their physicians made all decisions regarding dose changes and medication discontinuation or switch.
Treatment was randomized to initial starting doses of paroxetine 20 mg, fluoxetine hydrochloride 20 mg, or sertraline 50 mg. Included in the primary analysis at 9 months were 180 patients assigned to paroxetine, 184 to fluoxetine, and 182 to sertraline.
The investigators observed no significant group differences for any outcome at 3 and at 9 months. Patients who achieved an SF-36 Mental Component Summary score of 40 or greater by 9 months included 81% of those assigned to paroxetine, 77% of those assigned to fluoxetine and 84% of those assigned to sertraline.
Similar findings were recorded for other SF-36 scores, Symptoms Checklist 20 depression severity, depressive symptom count, and Health and Daily Living Form scale.
Among 451 subjects who responded at the end of the study, 81% reported their satisfaction with the SSRI prescribed for them as good, very good, or excellent, with no significant differences between groups.
The investigators found that sexual function measures tended to remain unchanged or slightly improved. Between 14% and 22% of patients switched to another antidepressant during the course of the study.
Dr. Kroenke's group concludes that these three SSRIs "do not differ across a wide array of psychological, social, work or other health-related quality of life domains in either the magnitude or the time course of response."
In an accompanying editorial, Dr. Gregory Simon, of the Group Health Cooperative in Seattle, remarks that even though the three SSRIs are nearly equivalent does not mean "they are equal for everyone." He points out that patients initially failing treatment often respond when a medication switch is made.
In an interview with Reuters Health, Dr. Simon suggested that variability in response may be due either to genetic variability in metabolism of the SSRIs or polymorphism at their sites of action.
A relatively surprising result, Dr. Simon said, is "the idea that particular characteristics of patients don't predict doing better with one SSRI than another. For example, we had thought that people with more sleep problems or anxiety would be better suited to a particular drug. However, no one has been able to demonstrate that."
"All other considerations being equal, an initial choice based on prescription costs is prudent, ethical, and clinically reasonable," Dr. Simon writes in his commentary. However, he adds, drafters of formulary policies would be not be acting ethically or prudently if they restricted use of any antidepressant for second- or third-line treatment.