What is the use of Fluoxetine (Selective Serotonin Reuptake Inhibitor, SSRI)?

From the Guidelines

Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) antidepressant that should be prescribed with caution, considering its potential side effects and interactions, as outlined in the clinical practice guideline for the assessment and treatment of children and adolescents with anxiety disorders 1.

Key Points

• The typical starting dose of fluoxetine is 20mg once daily, which can be increased to a maximum of 80mg daily if needed.
• Treatment duration varies based on the condition being treated, with depression typically requiring at least 6-9 months of therapy after symptom improvement.
• Besides depression, fluoxetine is also approved for obsessive-compulsive disorder, panic disorder, bulimia nervosa, and premenstrual dysphoric disorder.
• Common side effects include nausea, headache, insomnia, and sexual dysfunction, which often improve with continued use.
• Fluoxetine works by increasing serotonin levels in the brain by blocking its reuptake, which helps regulate mood, anxiety, and other neurological functions.
• It has a long half-life (2-3 days for the parent compound and 7-9 days for its active metabolite), allowing for once-daily dosing and making it less prone to withdrawal symptoms if doses are missed.
• Patients should be aware that full therapeutic effects may take 4-6 weeks to develop, and the medication should not be stopped abruptly but tapered gradually under medical supervision.
• The medication has a boxed warning for suicidal thinking and behavior through age 24 years, and close monitoring for suicidality is recommended, especially in the first months of treatment and following dosage adjustments 1.

Special Considerations

• Fluoxetine may interact with other medications, including monoamine oxidase inhibitors (MAOIs), and should be used cautiously in patients with a history of seizure disorder or other medical conditions.
• The medication may cause discontinuation syndrome, characterized by dizziness, fatigue, and other symptoms, if stopped abruptly or missed doses.
• Medical education, training, and experience are necessary to safely and effectively prescribe fluoxetine and other antidepressant medications.
• Parental oversight of medication regimens is of paramount importance in children and adolescents 1.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Overview of Fluoxetine

• Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) with demonstrated efficacy in the treatment of major depressive episodes 2.
• It has been evaluated for the treatment of obsessive-compulsive disorder (OCD) since 1985 and has been found to be effective in all published open-label studies as well as in placebo-controlled trials 2.
• The effective dose range of fluoxetine for OCD is 40 to 60 mg daily, with clinical evaluation carried out using specific scales such as the Y-BOCS or NIMH-OC 2.

Clinical Applications of Fluoxetine

• Fluoxetine has been found to be effective in the treatment of various psychiatric conditions, including obsessive-compulsive disorder, anorexia nervosa, bulimia nervosa, Tourette's syndrome, and trichotillomania 3.
• It has also been suggested for use in pain relief in certain diabetics, premenstrual syndrome, and migraine headache 3.
• Fluoxetine has been found to be as effective as clomipramine in the treatment of OCD, with a superior safety profile 2, 4.

Safety and Efficacy of Fluoxetine

• Fluoxetine has been found to be safe and effective in the treatment of depression, with a favorable safety profile compared to previously available antidepressants 4, 5.
• It has been found to be effective in the elderly population, as well as during pregnancy, and is not associated with an increased risk of suicide in controlled clinical trials 4.
• Common side effects of fluoxetine include gastrointestinal disturbances, headache, sedation, insomnia, activation, weight gain, impaired memory, excessive perspiration, paresthesia, and sexual dysfunction 5, 6.

Comparison with Other SSRIs

• Fluoxetine has been compared to other SSRIs, including sertraline, paroxetine, fluvoxamine, and citalopram, and has been found to have a similar pharmacologic profile 6.
• Important distinctions between the SSRIs are beginning to emerge with regard to adverse effect profiles and potential drug interactions 6.