What is fluoxetine (Prozac) used for treating?

Fluoxetine Treatment Indications

Fluoxetine is primarily indicated for the treatment of major depressive disorder, obsessive-compulsive disorder (OCD), bulimia nervosa, and panic disorder as established by FDA approval. 1

FDA-Approved Indications

Major Depressive Disorder

• Approved for adults and pediatric patients (children and adolescents)
• Efficacy established in 5-6 week trials with adult and geriatric outpatients
• Effective as maintenance therapy for up to 38 weeks following acute treatment 1

Obsessive-Compulsive Disorder (OCD)

• Approved for both adults and pediatric patients
• Effective dose range: 60-80 mg daily for optimal efficacy 2
• Efficacy established in 13-week trials with OCD outpatients 1
• Treats both obsessions and compulsions with a more favorable side-effect profile compared to older medications 3

Bulimia Nervosa

• Approved for moderate to severe bulimia (at least 3 bulimic episodes per week for 6 months)
• Effective at reducing binge-eating and vomiting behaviors
• Standard therapeutic dose: 60 mg/day 1
• Maintenance efficacy demonstrated for up to 52 weeks 1

Panic Disorder

• Approved for treatment with or without agoraphobia
• Efficacy established in 12-week clinical trials 1
• Lower starting doses (5 mg) may be beneficial for panic disorder patients who cannot tolerate standard 20 mg dosing 4

Other Clinical Applications (Off-Label Uses)

• Anxiety disorders: Effective for treating anxiety symptoms associated with depression 5
• Pain management: Used in certain pain conditions, particularly in patients with depression 6
• Premenstrual syndrome: Some evidence for efficacy 6
• Eating disorders: Effective for anorexia nervosa in addition to its approved use in bulimia 6

Pharmacological Considerations

• Metabolized through CYP2D6, which can lead to potential drug interactions 2
• Lower lethal potential in overdose compared to tricyclic antidepressants 2
• Black box warning for increased risk of suicidality in children, adolescents, and young adults 2
• FDA safety labeling indicates caution in patients with congenital long QT syndrome or history of QT prolongation 5

Dosing Considerations

• Major depression: Standard dose is 20 mg daily
• OCD: Higher doses (60-80 mg) typically required for optimal efficacy 2
• Panic disorder: Consider starting at lower doses (5 mg) and gradually increasing to 20 mg, as patients with panic disorder may be more sensitive to side effects 4
• CYP2D6 poor metabolizers: May require dose adjustment due to higher drug concentrations (3.9-11.5 fold higher AUC in poor metabolizers) 5

Important Clinical Pearls

• Response may take several weeks to develop fully
• Approximately 38% of patients may not respond during initial 6-12 weeks of treatment 2
• Higher doses increase risk of adverse effects and may lead to treatment discontinuation 5
• Fluoxetine has a long half-life, which reduces withdrawal symptoms upon discontinuation compared to other antidepressants 3
• Contraindicated in bipolar patients unless used with mood stabilizers, as it may trigger manic episodes 2

When prescribing fluoxetine, carefully consider the specific indication, appropriate dosing based on the condition being treated, and patient-specific factors such as CYP2D6 metabolizer status to maximize efficacy while minimizing adverse effects.