Switching from serotonin reuptake inhibitors to duloxetine in patients with resistant obsessive compulsive disorder: a case series.

Obsessive compulsive disorder (OCD) is a chronic disorder, currently recognized as one of the most common psychiatric disorder as well as one of the most disabling of all medical disorders. OCD is characterized by high rates of partial and/or absent response to standard, recommended treatments (serotonin reuptake inhibitors and psychotherapy). Recent investigation showed that Venlafaxine, a dual serotonin and norepinephrine reuptake inhibitor (SNRI), may be a valid alternative for some treatment-refractory patients. We present the cases of four OCD patients with comorbid mood or anxiety disorders, who were treated with serotonin reuptake inhibitors (SRIs) at adequate doses for at least 12 weeks, showing partial/no response. Patients were then switched to Duloxetine up to 120 mg/day and followed up for 12 weeks. Three out of four patients showed a Yale-Brown Obsessive Compulsive Scale(Y-BOCS) score reduction >or=35%. Duloxetine may be helpful in patients with treatment-resistant OCD, although larger and controlled studies are warranted to confirm this preliminary observation.