What is the recommended timing for taking Luvox (fluvoxamine)?

Fluvoxamine (Luvox) Dosing Time Recommendations

Fluvoxamine should be administered at bedtime as a single daily dose, particularly when starting treatment or when the total daily dose is 100mg or less. 1

Recommended Administration Schedule

• The FDA-approved administration for fluvoxamine in adults recommends a starting dose of 50mg as a single daily dose at bedtime 1
• For doses exceeding 100mg per day, it is advisable to split into two divided doses, with the larger dose given at bedtime 1
• When doses are divided, the evening/bedtime dose should be larger than the morning dose to minimize daytime side effects 1

Rationale for Bedtime Administration

• Bedtime administration helps manage common side effects that may occur with fluvoxamine, particularly:
  • Sedation and somnolence, which are among the more common adverse effects 2
  • Nausea, which is the most frequently reported adverse event (occurring in >10% of patients) 2
  • Other side effects including asthenia (weakness), headache, and dry mouth 2

Dosing Considerations

• The recommended starting dose for adults is 50mg at bedtime, with gradual increases in 50mg increments every 4-7 days as tolerated 1
• Maximum recommended dose is 300mg per day, though most therapeutic benefits are achieved between 100-300mg daily 1
• For elderly patients or those with hepatic impairment, lower initial doses and more gradual titration are recommended due to decreased clearance of fluvoxamine 1

Special Populations

• For pediatric patients (8-17 years), the starting dose is 25mg at bedtime, with more gradual titration in 25mg increments 1
• Children up to age 11 should not exceed 200mg/day 1
• Elderly patients may require lower doses due to decreased drug clearance 1, 3

Pharmacokinetic Considerations

• Fluvoxamine reaches peak plasma concentrations 2-8 hours after administration (for film-coated tablets) 3
• The drug has a biphasic elimination pattern with a terminal half-life of 12-15 hours after a single dose 3
• At steady state (reached after 5-10 days), the elimination half-life is prolonged by 30-50% 3

Common Pitfalls to Avoid

• Abrupt discontinuation should be avoided; a gradual dose reduction is recommended to prevent withdrawal symptoms 1
• Taking the full dose in the morning may increase daytime side effects like nausea and somnolence 2
• Failure to adjust dosing schedule when increasing beyond 100mg daily may lead to unnecessary side effects 1
• Fluvoxamine has significant drug interactions due to its inhibition of various cytochrome P450 enzymes, particularly CYP1A2, so medication timing should consider other drugs in the patient's regimen 3