Introduction: The high percentage (between 40% and 60%) of resistance to first-line drugs, such as clomipramine or selective serotonin reuptake inhibitors, is a major problem in the pharmacologic management of obsessive-compulsive disorder (OCD). In these cases, different strategies have been employed with controversial outcomes. The meager information available on the association of two serotonergic drugs prompted us to explore the possible effectiveness and tolerability of citalopram+clomipramine in resistant OCD patients.
Methods: Twenty outpatients with a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition diagnosis of OCD, who had failed to respond to at least two trials with a selective serotonin reuptake inhibitor and were currently taking clomipramine at different doses, were administered citalopram at a maximum dose of 60 mg/day. The clinical assessment was carried out at baseline (t0) and at the 4th (t1), 12th (t2), 24th (t3), 36th (t4), and 48th (t5) week by means of the Yale-Brown Obsessive Compulsive Scale, Hamilton Rating Scale for Depression, Clinical Global Impression scale, and the Dosage Record and Treatment Emergent Symptom Scale. The response was defined as a 35% decrease of the Yale-Brown Obsessive-Compulsive Scale total score.
Results: The results showed that approximately 50% of the patients improved significantly after 1 month of this regimen and after 1 year of treatment.
Conclusion: This study, although carried out in a small sample and in an open fashion, represents one of the few experiences with the association of two serotonergic compounds in resistant OCD and confirms its potential usefulness and good tolerability profile. Controlled research on this association in OCD is recommended.