Escitalopram and fluvoxamine combination therapy in a patient with treatment-resistant obsessive-compulsive disorder: a case report

Abstract

Selective serotonin reuptake inhibitors (SSRIs) are useful for the treatment of obsessive-compulsive disorder (OCD). Although combination therapies are recommended for treatment-resistant OCD, combination therapies involving the use of two SSRIs are not recommended. Here we report the case of a Japanese female who experienced improvement from combination therapy with escitalopram (ESC) and fluvoxamine (FLV). This patient had previously stopped taking other antidepressants because of tolerability issues. Since ESC had been partially effective, she refused to stop taking ESC. We therefore augmented her ESC therapy with FLV 25 mg/day, which resulted in inhibition of the metabolism of ESC by cytochrome P450 2C19 (CYP2C19). After this augmentation, the patient experienced a remarkable improvement in social functioning. The patient had a CYP2C19*1/*1 polymorphism. The patient's serum levels of ESC in the use of ESC plus FLV combination therapy and in the use of ESC alone were 67.7 ng/mL and 36.0 ng/mL, respectively. ESC and FLV combination therapy may be effective provided patients' CYP2C19 polymorphisms are checked and their serum concentrations of ESC are monitored.