Off-label higher doses of serotonin reuptake inhibitors in the treatment of obsessive-compulsive disorder: Safety and tolerability

Objective: To examine the long-term safety and tolerability of off-label high-dose serotonin reuptake inhibitors (OLHD-SRIs) in the treatment of obsessive-compulsive disorder (OCD). Methods: A retrospective longitudinal study was performed on 105 randomly selected outpatients diagnosed with OCD and were treated with OLHD-SRIs for at least 6 months. Patients received sertraline >200 mg/day, escitalopram >20 mg/day, fluvoxamine >300 mg/day, and fluoxetine >60 mg/day, combined with exposure and response prevention therapy. Patients were divided into three dosing groups: sertraline equivalent dose (SED) ≤ 200 mg/day (n = 26, 24.7%), 201–400 mg/day (n = 51, 48.5%) and 401–650 mg/day (n = 28, 26.6%). Safety and tolerability were assessed with an electrocardiogram, blood biochemistry, complete blood count, and side-effects monitoring. Results: SED ranged from 100 to 650 mg/day and the mean duration of OLHD-SRI treatment was 20.8 months. The most common side-effects reported were sexual dysfunction (n = 36, 34%), weight gain (n = 28, 27%), sedation (n = 27, 26%), hyperhidrosis (n = 20, 19%), and tremor (n = 11, 10%). Abnormal ECG was documented in one patient, and another patient experienced a first-time seizure, whereas elevated liver enzymes were seen in 4.8% of the sample (n = 5). None of the patients had serotonin syndrome or drug-induced liver injury. Side-effects did not differ among the three dosing groups. Conclusion: OLHD-SRIs appear to be safe and well tolerated in OCD patients in SED ≤ 650 mg/day doses and the side-effects did not differ between the three dosing groups.