July 1994

A Multicenter Investigation of Fixed-Dose Fluoxetine in the Treatment of Obsessive-compulsive Disorder

Author Affiliations

From the Psychopharmacology Division, Eli Lilly and Company, Indianapolis, Ind (Drs Tollefson, Rampey, Potvin, and Genduso); the Departments of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston (Dr Jenike), University of Texas Southwestern Medical School, Dallas (Dr Rush), University of Miami (Fla) School of Medicine, (Dr Dominguez); the Departments of Psychiatry and Behavioral Sciences, Stanford (Calif) University School of Medicine (Dr Koran); the Departments of Psychiatry, New York Hospital, Cornell University Medical College, Ithaca (Dr Shear); and Connecticut Mental Health Center, Yale University Medical School, New Haven (Dr Goodman). Dr Shear is currently with the University of Pittsburgh (Pa) Western Psychiatric Institute and Dr Goodman is currently with the University of Florida School of Medicine, Gainesville.

Arch Gen Psychiatry. 1994;51(7):559-567. doi:10.1001/archpsyc.1994.03950070051010

Objectives:  To determine the effectiveness of fluoxetine hydrochloride at fixed doses of 20 mg/d, 40 mg/d, and 60 mg/d in patients with obsessive-compulsive disorder (OCD) and to evaluate its safety.

Methods:  Fixed-dose fluoxetine hydrochloride (20 mg/d, 40 mg/d, 60 mg/d) was compared with placebo in two randomized, double-blind, parallel, 13-week trials of identical design in 355 outpatients with OCD aged 15 to 70 years (DSM-III-R criteria; 1 year's duration or longer; depression secondary if present).

Results:  Fluoxetine (all doses) was significantly (P±001) superior to placebo on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) total score (mean baseline-to-end—point decrease, 4.6,5.5, and 6.5 vs 0.9, respectively, studies pooled) and other efficacy measures (P±01). A trend suggesting greater efficacy at 60 mg/d was observed. Most patients (79.2%) completed the study. Eight adverse events were statistically significantly more frequent with fluoxetine and one, with placebo. For some events, incidence tended to increase with increasing dosage; however, few patients discontinued treatment for any single event.

Conclusion:  Fluoxetine was associated with a statistically significant reduction in OCD severity, including time engaged in obsessional and/or compulsive behaviors. Adverse events infrequently led to study discontinuation.