What is the recommended dose of fluvoxamine (Selective Serotonin Reuptake Inhibitor) for adults with obsessive-compulsive disorder?

Fluvoxamine Dosing for Obsessive-Compulsive Disorder in Adults

For adults with OCD, start fluvoxamine at 50 mg once daily at bedtime, then increase by 50 mg increments every 4-7 days as tolerated up to a maximum of 300 mg/day, with doses above 100 mg/day split into two divided doses (larger dose at bedtime). 1

Initial Dosing

• Starting dose: 50 mg once daily at bedtime 1
• This represents the FDA-approved initial dosing for adult patients with OCD 1

Titration Schedule

• Increase in 50 mg increments every 4-7 days as tolerated until maximum therapeutic benefit is achieved 1
• The titration should continue until optimal response is obtained, not exceeding 300 mg per day 1
• Therapeutic effect typically requires 100-300 mg/day based on controlled clinical trials establishing efficacy 1

Dose Administration

• Total daily doses >100 mg should be split into two divided doses 1
• Give the larger dose at bedtime when using unequal divided doses 1
• For the controlled-release formulation, 100-300 mg can be given once daily 2

Therapeutic Range and Duration

• Effective dose range: 100-300 mg/day in clinical trials demonstrating efficacy 3, 1, 4
• Minimum trial duration: 12 weeks at effective dosage to adequately assess response 1, 2
• Significant improvement may begin as early as week 2, with sustained response through 12 weeks 2
• Response rates of 38-52% have been reported with fluvoxamine versus 0-18% with placebo 4

Special Populations

Elderly or Hepatically Impaired Patients

• Modify initial dose and subsequent titration due to decreased clearance 1
• Start lower and titrate more slowly than in younger adults 1

Pediatric Patients (Ages 8-17)

• Starting dose: 25 mg once daily at bedtime 1
• Increase by 25 mg increments every 4-7 days as tolerated 1
• Maximum dose for children up to age 11: 200 mg/day 1
• Maximum dose for adolescents: 300 mg/day (same as adults) 1
• Doses >50 mg/day should be split into two divided doses, with larger dose at bedtime 1
• Female children may achieve therapeutic effect at lower doses 1

Maintenance Treatment

• Continue treatment long-term for responding patients, as OCD is a chronic condition 1
• Maintenance therapy may reduce relapse likelihood in up to 67% of patients 4
• Adjust dosage to maintain patient on lowest effective dose 1
• Periodically reassess to determine need for continued treatment 1

Discontinuation

• Taper gradually rather than stopping abruptly to minimize discontinuation symptoms 1
• Fluvoxamine has been associated with discontinuation syndrome, particularly given its shorter half-life compared to some other SSRIs 3
• Monitor patients for withdrawal symptoms during dose reduction 1

Clinical Considerations

• Fluvoxamine demonstrated superiority over placebo starting at week 2 in controlled trials, with mean YBOCS score reduction of 31.7% versus 21.2% for placebo at 12 weeks 2
• The drug is as effective as clomipramine but with better tolerability 4
• Common adverse effects include nausea (>10%), somnolence, asthenia, headache, dry mouth, and insomnia 4
• Exercise caution with drug interactions: fluvoxamine is a potent CYP1A2 inhibitor and moderate inhibitor of CYP2C19 and CYP3A4 3, 4
• Avoid concomitant use with alprazolam or triazolam due to interaction risk 3

High-Dose Considerations

• While the FDA-approved maximum is 300 mg/day 1, case reports describe remission with 600 mg/day in treatment-resistant OCD 5
• High doses beyond 300 mg/day should only be considered in treatment-resistant cases under close monitoring 5
• Standard practice should adhere to the 300 mg/day maximum unless other interventions have failed 1