What is the role of fluoxetine (selective serotonin reuptake inhibitor) in treating anxiety disorders in pediatric patients?

From the Guidelines

Fluoxetine is commonly used to treat anxiety disorders in children, typically starting at a low dose of 5-10 mg daily and potentially increasing to 20-60 mg daily based on response and tolerability, as recommended by the most recent guidelines 1.

Key Considerations

• Treatment usually begins with a lower dose for 1-2 weeks before considering adjustments, with full therapeutic effects often taking 4-6 weeks to develop 1.
• The medication should be taken consistently, preferably in the morning to minimize sleep disturbances.
• Common side effects include nausea, headache, sleep changes, and initial increases in anxiety, which typically improve over time.
• Parents should monitor for rare but serious side effects such as increased suicidal thoughts, especially during the first few weeks of treatment, as highlighted by the FDA black-box warning 1.

Monitoring and Maintenance

• Close monitoring is essential, particularly during the first few months of treatment and after dose changes, to assess for clinical worsening, suicidality, or unusual changes in behavior 1.
• Treatment typically continues for 6-12 months after symptom improvement, with gradual tapering when discontinuing to avoid withdrawal effects 1.
• Fluoxetine is most effective when combined with cognitive-behavioral therapy and should be prescribed as part of a comprehensive treatment plan under close medical supervision 1.

Important Safety Information

• The FDA has issued a black-box warning for suicidal thinking and behavior in children and adolescents treated with antidepressants, including fluoxetine 1.
• The risk of suicidal ideation and behavior is higher in the first few months of treatment and after dose changes, emphasizing the need for close monitoring 1.
• Fluoxetine has a boxed warning for suicidal thinking and behavior through age 24 years, and the pooled absolute rates for suicidal ideation across all antidepressant classes and all non-OCD anxiety indications have been reported to be 1% for youths treated with an antidepressant and 0.2% for youths treated with a placebo 1.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Fluoxetine Treatment for Children with Anxiety Disorders

• Fluoxetine has been studied as a treatment for children with anxiety disorders, including overanxious disorders, social phobia, and separation anxiety disorder 2, 3, 4.
• In an open study, 81% of patients showed moderate to marked improvement in anxiety symptoms after treatment with fluoxetine 2.
• Another study found that fluoxetine was effective in reducing anxiety symptoms and improving functioning in children and adolescents with generalized anxiety disorder, separation anxiety disorder, and/or social phobia 4.
• The severity of anxiety was significantly reduced from marked to mild in patients treated with fluoxetine, with an effect size of 2.3 2.

Dosage and Administration

• The dosage of fluoxetine used in these studies ranged from 5-40 mg daily, with a mean dose of 24 mg for children and 40 mg for adolescents 3.
• Fluoxetine was started at a low dose and increased weekly until improvement occurred or a maximum dose was reached 3.

Efficacy and Safety

• Fluoxetine has been shown to be effective and safe for the treatment of nondepressed children and adolescents with anxiety disorders other than OCD and panic disorder 2.
• Common side effects of fluoxetine included drowsiness, sleep problems, decreased appetite, nausea, abdominal pain, and excitement 3.
• No significant side effects were reported in one study, while another study found that fluoxetine was well tolerated except for mild and transient headaches and gastrointestinal side effects 2, 4.

Comparison with Other Treatments

• Fluoxetine has been compared to cognitive-behavioral therapy (CBT) and placebo in the treatment of adolescents with depression, and was found to be superior to CBT alone and placebo 5, 6.
• The combination of fluoxetine with CBT was found to be the most effective treatment for adolescents with depression, with a response rate of 71% 5.