From the Guidelines
Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) antidepressant that should be used to treat major depressive disorder, obsessive-compulsive disorder, panic disorder, bulimia nervosa, and premenstrual dysphoric disorder, with a typical starting dose of 20mg once daily, due to its efficacy and safety profile as demonstrated in recent studies 1. The use of fluoxetine is supported by its FDA approval for various conditions, including major depressive disorder, obsessive-compulsive disorder, panic disorder, bulimia nervosa, and premenstrual dysphoric disorder 1. Some key points to consider when using fluoxetine include:
- The typical starting dose is 20mg once daily, which may be increased to a maximum of 80mg daily if needed 1
- Treatment duration varies based on the condition being treated, with depression typically requiring at least 6-9 months of therapy after symptom improvement
- 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 reabsorption, which helps regulate mood, anxiety, and other psychological 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 1
- Patients should be aware that therapeutic effects typically take 2-4 weeks to become noticeable, and the medication should not be stopped abruptly without medical supervision
- Recent studies have also addressed the risk of suicidality in adolescents and young adults treated with fluoxetine, suggesting that the risk of not prescribing antidepressant medication is significantly higher than the risk of prescribing 1
From the FDA Drug Label
CLINICAL PHARMACOLOGYPharmacodynamicsThe antidepressant, antiobsessive compulsive, and antibulimic actions of fluoxetine are presumed to be linked to its inhibition of CNS neuronal uptake of serotonin.
The use of Fluoxetine, a Selective Serotonin Reuptake Inhibitor (SSRI), is for the treatment of:
- Major Depressive Disorder
- Obsessive-Compulsive Disorder (OCD)
- Bulimia Its mechanism of action is linked to its inhibition of CNS neuronal uptake of serotonin 2.
From the Research
Use of Fluoxetine
- Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) with demonstrated efficacy in the treatment of major depressive episodes 3, 4.
- It has been evaluated for the treatment of obsessive-compulsive disorder (OCD) since 1985, and has been found to be effective in OCD in all published open-label studies as well as in placebo-controlled trials 3.
- The effective dose range of fluoxetine for OCD is 40 to 60 mg daily, and clinical evaluation is carried out using specific scales such as the Y-BOCS or NIMH-OC 3.
- Fluoxetine has also been found to be effective in alleviating collateral depressive symptoms in OCD patients, significantly reducing suicidal ideation and impulsiveness 3.
Clinical Applications
- Fluoxetine has been used in the management of various psychiatric conditions, including:
- Fluoxetine has also been suggested for use in pain relief in certain diabetics, premenstrual syndrome, and migraine headache 6.
Pharmacokinetics and Pharmacodynamics
- Fluoxetine has a half-life of 2-7 days, and its active metabolite norfluoxetine has a half-life of 4-15 days 4.
- The pharmacokinetic and pharmacodynamic properties of fluoxetine are well described, and its therapeutic response in major depression may be due to a progressive desensitization of somatodendritic 5-HT autoreceptors in the midbrain raphe nucleus 4.
- Fluoxetine's efficacy in major depressive disorder has been assessed in numerous clinical controlled trials, and meta-analyses have confirmed its efficacy compared to tricyclic antidepressants and placebo 4.