Fluoxetine Pharmacokinetics and Administration

Special Considerations

• Fluoxetine has a very long half-life (1-3 days for fluoxetine, 4-16 days for its active metabolite norfluoxetine), and due to its activating properties, morning dosing is preferred to avoid insomnia, with side effects potentially developing over several weeks of treatment due to the long half-life 1
• The American College of Physicians and other medical societies recommend that fluoxetine should be used with caution in patients with congenital long QT syndrome, previous history of QT prolongation, or family history of long QT syndrome, and CYP2D6 poor metabolizers may experience higher plasma concentrations and potentially more side effects 2