Description
Description
Class:
Selective Serotonin Reuptake Inhibitor (SSRI)
Forms:
Tablets (10 mg, 20 mg), Capsules, Oral Solution
Mechanism of Action:
Fluoxetine selectively inhibits the reuptake of serotonin (5-HT) in the brain, increasing serotonin levels at the synaptic cleft, thereby improving mood, emotional stability, and behavior.
Usual Adult Dosage:
- Depression / OCD: 20 mg once daily, may be increased gradually (max 60 mg/day)
- Panic Disorder: Start with 10 mg/day; usual range 20–60 mg/day
- Bulimia Nervosa: 60 mg/day
Doses should be adjusted based on patient response and tolerability.
Indications:
- Major Depressive Disorder (MDD)
- Obsessive-Compulsive Disorder (OCD)
- Panic Disorder
- Bulimia Nervosa
- Premenstrual Dysphoric Disorder (PMDD)
- Anxiety disorders (off-label)
Common Side Effects:
- Nausea
- Gastritis
- Insomnia
- Sexual dysfunction
- Weight changes (usually loss early in treatment)
Warnings & Precautions:
- Suicidal thoughts (especially in adolescents and young adults)
- Risk of Serotonin Syndrome when combined with other serotonergic drugs
- QT prolongation at higher doses
- Withdrawal symptoms if stopped abruptly
- Avoid with MAO inhibitors (at least 14-day gap required)
Half-Life Advantage:
Fluoxetine has a long half-life (2–4 days; active metabolite ~7–15 days), allowing:
- Once-daily dosing
- Lower risk of withdrawal effects compared to other SSRIs