Maximum Recommended Dose of Fluoxetine (Lovan)
The maximum recommended dose of fluoxetine (Lovan) is 80 mg per day, though most patients respond adequately to doses between 20-60 mg daily. 1
General Dosing Guidelines
Major Depressive Disorder
- Initial dose: 20 mg once daily in the morning 1
- Dose increases may be considered after several weeks if insufficient clinical improvement is observed 1
- Doses above 20 mg/day may be administered once daily (morning) or twice daily (morning and noon) 1
- Maximum dose: 80 mg/day 1
Obsessive-Compulsive Disorder
- Initial dose: 20 mg/day in the morning 1
- Dose range: 20-60 mg/day is recommended 1
- Maximum dose: 80 mg/day (well tolerated in open studies) 1
- Full therapeutic effect may be delayed until 5 weeks of treatment or longer 1
Bulimia Nervosa
- Recommended dose: 60 mg/day (administered in the morning) 1
- For some patients, titration to target dose over several days may be advisable 1
- Doses above 60 mg/day have not been systematically studied in bulimia 1
Special Populations
Pediatric Patients
- For depression in children/adolescents: 10-20 mg/day 1
- Lower weight children may start with 10 mg/day 1
- For OCD in adolescents: Initial 10 mg/day, increase to 20 mg/day after 2 weeks, with a range of 20-60 mg/day 1
- For OCD in lower weight children: Initial 10 mg/day with a range of 20-30 mg/day 1
Patients Requiring Dose Adjustments
- Lower or less frequent dosing should be used in: 1
- Patients with hepatic impairment
- Elderly patients
- Patients with concurrent disease
- Patients on multiple concomitant medications
Safety Considerations
- Common adverse events at the recommended 20 mg/day dose affect the gastrointestinal and nervous systems 2
- Higher doses (approaching 80 mg/day) are associated with increased frequency of adverse events 2
- The long half-life of fluoxetine (1-3 days) and its active metabolite norfluoxetine (7 days) essentially preclude a withdrawal phenomenon 2, 3
- Fluoxetine inhibits cytochrome P450 (CYP) 2D6 and other CYP enzymes, increasing potential for drug interactions 2
Clinical Pearls
- Some patients, particularly those with panic disorder, may benefit from starting at lower doses (5 mg/day) and gradually increasing to standard doses 4
- Studies have shown that the 20 mg/day dose is efficacious while maintaining a favorable side effect profile compared to higher doses 5
- For maintenance treatment in major depression, 20 mg/day has shown efficacy for up to 38 weeks following 12 weeks of acute treatment 1
Remember that while 80 mg/day is the maximum recommended dose, most patients respond adequately to lower doses, and dose increases should be made only after allowing sufficient time to observe clinical response.