What are the recommended dosing guidelines, safety precautions, and contraindications for Luvox (fluvoxamine) when used to treat obsessive‑compulsive disorder in adults and children?

Luvox (Fluvoxamine) for Obsessive-Compulsive Disorder: Dosing, Safety, and Contraindications

Fluvoxamine is highly effective for OCD in both adults and children, but requires careful attention to its extensive drug interaction profile, black-box warning for suicidality through age 24, and specific dosing adjustments based on age. 1

Adult Dosing

• Start at 50 mg once daily at bedtime, then increase in 50 mg increments every 4–7 days as tolerated, targeting 100–300 mg/day (maximum 300 mg/day). 2
• Divide doses above 100 mg/day into twice-daily administration, giving the larger dose at bedtime. 2
• Therapeutic response typically occurs by week 6, with maximal benefit by weeks 10–12 or later; at least 8–10 weeks at maximum tolerated dose is required before declaring treatment failure. 3
• Response rates are 38–52% versus 0–18% with placebo, with efficacy equivalent to clomipramine but superior tolerability. 1, 4

Pediatric Dosing (Ages 8–17)

• Start at 25 mg once daily at bedtime to minimize early treatment-emergent anxiety or agitation. 2, 1
• Titrate weekly by 25–50 mg increments to a target range of 50–200 mg/day in children up to age 11 (maximum 200 mg/day) or up to 300 mg/day in adolescents. 2, 1
• Use twice-daily dosing at any dose in youth due to shorter half-life, with the larger dose at bedtime if doses are unequal. 1, 2
• Steady-state plasma concentrations are 2–3 times higher in children (ages 6–11) than adolescents, necessitating the lower 200 mg/day maximum in younger children. 5, 6

Critical Safety Monitoring

Black-Box Warning for Suicidality

• All patients through age 24 require intensive monitoring for suicidal thinking and behavior, especially during the first month and after dose adjustments. 2, 1
• Pooled absolute risk: 1% with antidepressants versus 0.2% with placebo (risk difference 0.7%, NNH = 143). 1
• Contact patients shortly after initiation to review adherence, current status, and emergence of adverse events. 3

Behavioral Activation

• Monitor for motor/mental restlessness, insomnia, impulsiveness, disinhibited behavior, or aggression, particularly in the first month or with dose increases, as activation is more common in younger patients and anxiety disorders. 1
• Begin with a subtherapeutic "test" dose (25 mg in pediatrics, 50 mg in adults) to minimize early treatment-emergent activation. 1

Serotonin Syndrome

• Monitor for confusion, agitation, tremor, clonus, hyperreflexia, muscle rigidity, and autonomic instability, especially within 24–48 hours after dose changes or when combined with other serotonergic agents. 3

Absolute Contraindications

• Never co-administer with MAOIs due to high risk of serotonin syndrome. 3, 2
• Avoid drugs that prolong the QT interval due to risk of additive QT prolongation. 3

Drug Interaction Profile

Fluvoxamine has the most extensive drug interaction profile among SSRIs, requiring careful attention to concomitant medications. 1

• Potent inhibitor of CYP1A2 and moderate inhibitor of CYP2C19, CYP2C9, CYP3A4, and CYP2D6. 3, 2
• Exercise particular caution with alprazolam or triazolam, as fluvoxamine significantly increases their levels. 3
• As fluvoxamine is discontinued, medications previously affected by these interactions may have increased clearance, potentially requiring dose adjustments. 7

Discontinuation Protocol

• Taper gradually over 1–2 weeks rather than stopping abruptly to minimize discontinuation syndrome. 3, 2
• Discontinuation syndrome includes dizziness, fatigue, myalgias, headaches, nausea, insomnia, sensory disturbances, paresthesias, anxiety, and agitation; fluvoxamine is specifically associated with these withdrawal symptoms due to its shorter half-life. 7, 3
• If intolerable symptoms occur following dose reduction, resume the previously prescribed dose and decrease more gradually. 2

Special Populations

Elderly and Hepatically Impaired

• Modify initial dose and subsequent titration due to decreased clearance of fluvoxamine in these populations. 2

Pregnant Women (Third Trimester)

• Carefully weigh risks versus benefits, as neonates exposed late in the third trimester have developed complications requiring prolonged hospitalization, respiratory support, and tube feeding. 2
• Consider tapering in the third trimester if clinically appropriate. 2

Combination with Cognitive-Behavioral Therapy

• For moderate to severe OCD or anxiety presentations, combination treatment with CBT plus fluvoxamine is preferable to monotherapy, yielding larger effect sizes than SSRI alone. 1
• Offer 10–20 sessions of exposure and response prevention (ERP) when feasible. 1

Common Pitfalls to Avoid

• Do not undertitrate: OCD typically requires higher SSRI doses (100–300 mg/day in adults) for adequate response. 1, 2
• Do not dismiss early sedation or activation: persistent adverse effects at low doses signal the need for medication change or slower titration. 1
• Do not abruptly discontinue: this dramatically increases risk of discontinuation syndrome. 7, 3
• Do not overlook drug interactions: fluvoxamine's extensive CYP450 inhibition requires systematic review of all concurrent medications. 3
• Parental oversight of medication regimens is paramount in adolescents, and parents must be educated about potential side effects including suicidality. 1