Overview
11 DESCRIPTION Fluoxetine capsules, USP are a selective serotonin reuptake inhibitor for oral administration. It is also marketed for the treatment of premenstrual dysphoric disorder (Sarafem ® , fluoxetine hydrochloride). It is designated (±)-N-methyl-3-phenyl-3-[(α,α,α-trifluoro- p -tolyl)oxy]propylamine hydrochloride and has the empirical formula of C 17 H 18 F 3 NO•HCl.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Although the exact mechanism of fluoxetine is unknown, it is presumed to be linked to its inhibition of CNS neuronal uptake of serotonin. 12.2 Pharmacodynamics Studies at clinically relevant doses in man have demonstrated that fluoxetine blocks the uptake of serotonin into human platelets. Studies in animals also suggest that fluoxetine is a much more potent uptake inhibitor of serotonin than of norepinephrine. Antagonism of muscarinic, histaminergic, and α 1 -adrenergic receptors has been hypothesized to be associated with various anticholinergic, sedative, and cardiovascular effects of classical tricyclic antidepressant (TCA) drugs.
Indications
- 1 INDICATIONS AND USAGE Fluoxetine is indicated for the treatment of: Acute and maintenance treatment of Major Depressive Disorder [see Clinical Studies (14.1) ] . Acute and maintenance treatment of obsessions and compulsions in patients with Obsessive Compulsive Disorder (OCD) [see Clinical Studies (14.2) ] . Acute and maintenance treatment of binge-eating and vomiting behaviors in patients with moderate to severe Bulimia Nervosa [see Clinical Studies (14.3) ] . Acute treatment of Panic Disorder, with or without agoraphobia [see Clinical Studies (14.4) ] .
Common Doses
- 20 mg
- 10 mg
- 60 mg
- 5 mg
Dosage
2 DOSAGE AND ADMINISTRATION Indication Adult Pediatric MDD ( 2.1 ) 20 mg/day in am (initial dose) 10 to 20 mg/day (initial dose) OCD ( 2.2 ) 20 mg/day in am (initial dose) 10 mg/day (initial dose) Bulimia Nervosa ( 2.3 ) 60 mg/day in am Panic Disorder ( 2.4 ) 10 mg/day (initial dose) Depressive Episodes Associated with Bipolar I Disorder ( 2.5 ) Oral in combination with olanzapine: 5 mg of oral olanzapine and 20 mg of fluoxetine once daily (initial dose) Oral in combination with olanzapine: 2.
Black Box Warning
WARNING: SUICIDAL THOUGHTS AND BEHAVIORS Antidepressants increased the risk of suicidal thoughts and behavior in children, adolescents, and young adults in short-term studies. These studies did not show an increase in the risk of suicidal thoughts and behavior with antidepressant use in patients over age 24; there was a reduction in risk with antidepressant use in patients aged 65 and older [see Warnings and Precautions (5.1) ] . In patients of all ages who are started on antidepressant therapy, monitor closely for worsening and for emergence of suicidal thoughts and behaviors.
Contraindications
- 4 CONTRAINDICATIONS When using fluoxetine capsules and olanzapine in combination, also refer to the Contraindications section of the package insert for Symbyax. Serotonin Syndrome and MAOIs: Do not use MAOIs intended to treat psychiatric disorders with fluoxetine or within 5 weeks of stopping treatment with fluoxetine. Do not use fluoxetine within 14 days of stopping an MAOI intended to treat psychiatric disorders. In addition, do not start fluoxetine in a patient who is being treated with linezolid or intravenous methylene blue ( 4.1 ) Pimozide: Do not use.
Side Effects
- 6 ADVERSE REACTIONS The following adverse reactions are discussed in more detail in other sections of the labeling: Suicidal Thoughts and Behaviors in Children, Adolescents, and Young Adults [see Boxed Warning and Warnings and Precautions (5.1) ] Serotonin Syndrome [see Warnings and Precautions (5.2) ] Allergic Reactions and Rash [see Warnings and Precautions (5.3) ] Screening Patients for Bipolar Disorder and Monitoring for Mania/Hypomania [see Warnings and Precautions (5.4) ] Seizures [see Warnings and Precautions (5.5) ] Altered Appetite and Weight [see Warnings and Precautions (5.
Interactions
- 7 DRUG INTERACTIONS As with all drugs, the potential for interaction by a variety of mechanisms (e.g., pharmacodynamic, pharmacokinetic drug inhibition or enhancement, etc.) is a possibility. Monoamine Oxidase Inhibitors (MAOIs): ( 2.9 , 2.10 , 4.1 , 5.2 ) Drugs Metabolized by CYP2D6: Fluoxetine is a potent inhibitor of CYP2D6 enzyme pathway ( 7.7 ) Tricyclic Antidepressants (TCAs): Monitor TCA levels during coadministration with fluoxetine or when fluoxetine has been recently discontinued ( 5.2 , 7.