What is the initial dose and maximum dose of fluvoxamine (Selective Serotonin Reuptake Inhibitor - SSRI) for treating Obsessive-Compulsive Disorder (OCD)?

How to Start and Titrate Fluvoxamine for OCD

Initial Dosing

For adults, start fluvoxamine at 50 mg once daily at bedtime, and for children/adolescents ages 8-17, start at 25 mg once daily at bedtime. 1

• The lower pediatric starting dose accounts for the 2-3 times higher steady-state plasma concentrations observed in children aged 6-11 years compared to adolescents 2
• Single daily dosing at bedtime minimizes daytime side effects during the initial titration phase 1

Titration Schedule

Increase the dose by 50 mg increments every 4-7 days in adults (or 25 mg increments in children) as tolerated until maximum therapeutic benefit is achieved. 1

• Once the total daily dose exceeds 100 mg in adults (or 50 mg in pediatric patients), split into two divided doses with the larger dose given at bedtime 1
• Therapeutic response typically occurs by week 6, with maximal benefit by weeks 10-12 or later, so patience during titration is essential 3
• The controlled trials establishing efficacy used dose ranges of 100-300 mg/day in adults and 50-200 mg/day in pediatric patients 1, 4

Maximum Doses

The maximum dose is 300 mg/day for adults and adolescents ages 12-17, and 200 mg/day for children up to age 11. 3, 1, 2

• The American Academy of Family Physicians specifically recommends a maximum of 150 mg twice daily (300 mg total) for OCD 3
• Female children may achieve therapeutic effect at lower doses due to pharmacokinetic differences 1
• Elderly patients and those with hepatic impairment require lower initial doses and slower titration due to decreased clearance 1

Critical Safety Monitoring

Monitor intensively for suicidal ideation in patients ≤24 years old during the first months of treatment and after every dose adjustment. 3

• The FDA black-box warning mandates close observation for clinical worsening, suicidality, and unusual behavioral changes, especially during initial treatment and dose changes 5
• Contact patients (in-person or by telephone) shortly after initiation to review adherence, current status, and emergence of adverse events 5
• Common adverse events include insomnia, asthenia, abdominal discomfort, nausea, and CNS symptoms, though most occur at similar rates to placebo 2, 4

Important Drug Interactions

Fluvoxamine is absolutely contraindicated with MAOIs due to serotonin syndrome risk. 3

• Fluvoxamine is a potent CYP1A2 inhibitor and moderately inhibits CYP2C19, CYP2C9, CYP3A4, and CYP2D6, requiring careful review of all concurrent medications 3
• Exercise particular caution with alprazolam and triazolam, as fluvoxamine significantly increases their levels 3

Discontinuation Protocol

Always taper fluvoxamine gradually over 1-2 weeks rather than stopping abruptly to minimize discontinuation syndrome. 6, 3

• Fluvoxamine is specifically associated with withdrawal symptoms including dizziness, fatigue, sensory disturbances, paresthesias, anxiety, and agitation 6
• If intolerable symptoms occur during taper, resume the previous dose and decrease more gradually 1

Common Pitfalls to Avoid

• Do not use inadequate doses or insufficient duration: Higher doses are required for OCD than for depression or other anxiety disorders, and at least 8-10 weeks at maximum tolerated dose is needed before declaring treatment failure 5
• Do not start at high doses: Starting at higher than recommended doses increases risk of deliberate self-harm and suicide-related events 5
• Do not ignore the need for divided dosing: Once exceeding 100 mg/day in adults, failure to split doses increases side effect burden 1