Fluvoxamine Titration Protocol
The recommended fluvoxamine titration schedule for adults is to start at 50 mg once daily at bedtime, then increase by 50 mg every 4-7 days as tolerated, up to a maximum of 300 mg daily. 1
Adult Dosing Schedule
- Initial dose: 50 mg once daily at bedtime
- Titration rate: Increase by 50 mg increments every 4-7 days as tolerated
- Maximum dose: 300 mg per day
- Dosing frequency:
- Doses ≤100 mg: Can be given as a single daily dose at bedtime
- Doses >100 mg: Should be divided into two daily doses, with the larger dose at bedtime 1
Special Population Considerations
Pediatric Patients
Ages 8-11:
- Starting dose: 25 mg once daily at bedtime
- Titration: Increase by 25 mg every 4-7 days as tolerated
- Maximum dose: 200 mg/day
- Note: Therapeutic effect in female children may be achieved with lower doses 1
Ages 12-17:
Elderly Patients
- Start at lower doses due to decreased clearance
- More cautious titration may be appropriate 1
Hepatically Impaired Patients
- Start at lower doses due to decreased clearance
- More cautious titration may be appropriate 1
Pharmacokinetic Considerations
- Fluvoxamine reaches peak plasma concentrations in 2-8 hours for standard tablets 3
- Steady-state plasma concentrations are achieved within 5-10 days 3
- Terminal elimination half-life is 12-15 hours after a single dose, prolonged by 30-50% at steady state 3
- Fluvoxamine displays nonlinear pharmacokinetics, with disproportionally higher plasma concentrations at higher doses 3
Important Clinical Considerations
Drug Interactions
- Fluvoxamine is a potent inhibitor of CYP1A2 and less potently inhibits CYP3A4 and CYP2D6 3
- Significant interactions with:
- Tricyclic antidepressants
- Benzodiazepines (alprazolam, bromazepam, diazepam)
- Theophylline
- Propranolol
- Warfarin
- Carbamazepine 3
- Contraindicated with MAOIs due to risk of serotonin syndrome 4
Adverse Effects Management
- Most common side effects involve the CNS or gastrointestinal system 5
- Gastrointestinal effects (especially nausea) are common but generally mild to moderate 6
- Monitor for:
- Nausea and vomiting
- Headache
- Insomnia or somnolence
- Dizziness 4
Discontinuation
- Gradual tapering rather than abrupt cessation is recommended
- Monitor for discontinuation symptoms (dizziness, sensory disturbances, anxiety, irritability) 1, 4
- Paroxetine, fluvoxamine, and sertraline have been associated with discontinuation syndrome 4
Clinical Pearls
- Fluvoxamine has a more favorable tolerability profile than tricyclic antidepressants in terms of cardiotoxicity, anticholinergic effects, sedation, and weight gain 6
- For patients with anxiety disorders, fluvoxamine has demonstrated efficacy in OCD, social phobia, separation anxiety disorder, and generalized anxiety disorder 5
- If doses exceed 100 mg daily, divide into two doses with the larger portion at bedtime to minimize daytime sedation 1
- Steady-state concentrations are 30-50% higher than predicted from single-dose data, which is important to consider during titration 3
By following this structured titration protocol and monitoring for adverse effects, clinicians can optimize the safety and efficacy of fluvoxamine treatment while minimizing potential side effects and complications.