Long-term outcomes of initial antidepressant drug choice in a "real world"randomized trial

Objective: To compare the long-term clinical, quality-of-life, and economic outcomes after an initial prescription for fluoxetine, imipramine hydrochl oride, or desipramine hydrochloride. Design: Randomized, controlled trial. Setting: Primary care clinics of a staff-model health maintenance organizat ion in the Seattle, Wash, area. Patients: Four hundred seventy-one adults beginning antidepressant drug tre atment for depression. Intervention: Random assignment of initial medication (desipramine, fluoxet ine, or imipramine),with treatment (dosing, medication changes or discontin uation, and follow-up visits) managed by a primary care physician. Measurements: Interviews at baseline and at 6, 9, 12, 18, and 24 months exa mined medication use, clinical outcomes (Hamilton Depression Rating Scale a nd depression subscale of the Hopkins Symptom Checklist), and quality of li fe (Medical Outcomes Study SF-36 Health Survey). Medical costs were assesse d using the health maintenance organization's accounting data. Results: Patients assigned to fluoxetine therapy were significantly more li kely to continue taking the initial antidepressant but no more likely to co ntinue any antidepressant therapy. The fluoxetine group did not differ sign ificantly from either tricyclic drug group on any measure of depression sev erity or quality of life. For 24 months, antidepressant drug costs were app roximately $250 higher for patients assigned to fluoxetine therapy, but tot al medical costs were essentially identical. Conclusions: Initial selection of fluoxetine or a tricyclic antidepressant drug should lead to similar clinical outcomes, functional outcomes, and ove rall costs. Differences in antidepressant prescription costs are blunted by the large minority of tricyclic treated patients who switch to use of more expensive medications. Restrictions on first-line use of fluoxetine in pri mary care will probably not reduce overall treatment costs.