What is the recommended titration schedule for fluoxetine (selective serotonin reuptake inhibitor)?

Fluoxetine Titration Schedule

For adults with depression, the recommended initial dose of fluoxetine is 20 mg/day administered in the morning, with potential increases after several weeks if insufficient clinical improvement is observed. 1

Initial Dosing for Different Conditions

Major Depressive Disorder

• For adults, start with 20 mg/day administered in the morning 1
• For pediatric patients, start with 10 mg/day for lower weight children and 10-20 mg/day for adolescents and higher weight children, with potential increase to 20 mg/day after 1 week 1
• The American Academy of Family Physicians alternatively recommends starting with 10 mg every other morning or 10 mg daily for some adult patients 2

Obsessive-Compulsive Disorder (OCD)

• For adults, start with 20 mg/day administered in the morning 1
• For adolescents and higher weight children, start with 10 mg/day, increasing to 20 mg/day after 2 weeks 1
• For lower weight children, start with 10 mg/day with potential increases after several weeks 1

Bulimia Nervosa

• Recommended dose is 60 mg/day administered in the morning 1
• For some patients, it may be advisable to titrate up to this target dose over several days 1

Panic Disorder

• Start with 10 mg/day, then increase to 20 mg/day after 1 week 1
• Most frequently administered dose in clinical trials was 20 mg/day 1

Dosage Adjustments and Considerations

• Morning dosing is preferred as fluoxetine is activating and may cause insomnia if taken later in the day 2
• Due to fluoxetine's very long half-life (1-3 days for fluoxetine, 4-16 days for its active metabolite norfluoxetine), side effects may not appear immediately but can develop over several weeks of treatment 2, 3
• Lower or less frequent dosage should be used in patients with hepatic impairment 1
• Lower or less frequent dosage should be considered for elderly patients and those with concurrent disease or on multiple medications 1
• Dosage adjustments for renal impairment are not routinely necessary 1

Dose Range and Maximum Doses

• For depression: Dose range of 20-80 mg/day, not to exceed 80 mg/day 1
• For OCD: Dose range of 20-60 mg/day, not to exceed 80 mg/day 1
• For bulimia nervosa: Recommended dose is 60 mg/day 1
• For panic disorder: Dose range of 10-60 mg/day 1

Special Considerations

Dose Increases for Relapse

• For patients who relapse while on fluoxetine, increasing the dose can be beneficial 4
• In one study, 57% of patients responded to an increase from 20 mg/day to 40 mg/day 4

Low-Dose Initiation

• Some patients, particularly those with panic disorder, may benefit from starting at lower doses (e.g., 5 mg/day) and gradually increasing to standard doses 5
• This approach may be useful for patients who cannot tolerate the standard 20 mg dose but appear to benefit from lower doses 5

Weekly Dosing for Maintenance

• Once-weekly dosing may be an option for maintenance treatment in some conditions due to the long half-life of fluoxetine and its active metabolite 6
• Weekly dosing should be initiated 7 days after the last daily dose of fluoxetine 20 mg 1

Titration Schedule Summary

1. Start with recommended initial dose based on condition and patient characteristics
2. Allow 4-8 weeks for full therapeutic effect to manifest 1, 7
3. Consider dose increases if insufficient clinical improvement is observed after several weeks
4. Maintain patient on the lowest effective dose
5. For long-term treatment, consider continuation at effective dose or potential switch to weekly dosing where appropriate