Nurses Compass
Drug Guide
Fluoxetine Hydrochloride
Classification
Therapeutic: Antidepressant, Selective Serotonin Reuptake Inhibitor (SSRI)
Pharmacological: Selective Serotonin Reuptake Inhibitor (SSRI)
FDA Approved Indications
- Major depressive disorder
- Obsessive-compulsive disorder (OCD)
- Bulimia nervosa
- Panic disorder
- Premenstrual dysphoric disorder (PMDD)
Mechanism of Action
Fluoxetine selectively inhibits the serotonin reuptake transporter, increasing serotonin levels in the synaptic cleft, which helps improve mood and reduce anxiety.
Dosage and Administration
Adult: Typically 20 mg once daily, may be adjusted based on response and tolerability. For some conditions, higher doses up to 80 mg/day may be used.
Pediatric: Starting dose usually 10-20 mg/day; titrate gradually. Maximum dose 20 mg/day for children and adolescents for depression.
Geriatric: Start at lower doses (e.g., 10 mg/day), monitor closely; adjust as needed.
Renal Impairment: Use with caution; no specific adjustment recommended but monitor for side effects.
Hepatic Impairment: Start at lower doses; titrate slowly, monitor for increased side effects.
Pharmacokinetics
Absorption: Well absorbed orally, with peak plasma concentrations in 6-8 hours.
Distribution: Widely distributed; crosses the blood-brain barrier.
Metabolism: Hepatically metabolized via CYP2D6 to active metabolites.
Excretion: Primarily via urine; with a half-life of 2-4 days (after chronic dosing).
Half Life: Approximately 2-4 days, allowing once-daily dosing.
Contraindications
- Known hypersensitivity to fluoxetine or any component.
- Use within 14 days of monoamine oxidase inhibitors (MAOIs).
Precautions
- History of bipolar disorder, suicide risk, bleeding disorders, hyponatremia, seizure disorder. Caution in hepatic impairment, diabetes, and concomitant use of other serotonergic drugs. Pregnant or breastfeeding women should consult their healthcare provider.
Adverse Reactions - Common
- Nausea (Frequent)
- Insomnia (Frequent)
- Anxiety (Frequent)
- Headache (Frequent)
- Diarrhea (Frequent)
Adverse Reactions - Serious
- Serotonin syndrome (confusion, hallucination, seizure, extreme changes in blood pressure) (Rare)
- Suicidal ideation, especially in young adults and adolescents (Monitor closely)
- Bleeding risk, including bruising and bleeding (Rare)
Drug-Drug Interactions
- Monoamine oxidase inhibitors (MAOIs), Thioridazine, Pimozide, Clopidogrel, NSAIDs, anticoagulants, other serotonergic agents
Drug-Food Interactions
- Avoid alcohol and foods affecting bleeding risk (e.g., gingko, fish oil).
Drug-Herb Interactions
- St. John's Wort, Ginseng, Valerian
Nursing Implications
Assessment: Monitor mood, suicidal ideation, serotonin syndrome symptoms, and adverse effects.
Diagnoses:
- Risk for injury related to adverse drug effects, suicidal ideation.
Implementation: Administer as prescribed, assess for therapeutic response and side effects, educate patient.
Evaluation: Assess improvement in depression, anxiety, or OCD symptoms; monitor for adverse reactions.
Patient/Family Teaching
- Take medication exactly as prescribed. Do not discontinue abruptly.
- Report any unusual thoughts, behaviors, or side effects.
- Avoid alcohol and hazardous activities until settled.
- Inform healthcare provider of all medications and supplements.
Special Considerations
Black Box Warnings:
- Risk of increased suicidal thoughts and behavior in children, adolescents, and young adults.
Genetic Factors: Polymorphisms in CYP2D6 may affect drug metabolism.
Lab Test Interference: No significant interference reported.
Overdose Management
Signs/Symptoms: Nausea, vomiting, seizures, arrhythmias, somnolence, serotonin syndrome.
Treatment: Supportive care, activated charcoal if early, serotonin syndrome management with serotonin antagonists like cyproheptadine, and symptomatic treatment.
Storage and Handling
Storage: Store at room temperature, 20-25°C (68-77°F).
Stability: Stable under recommended storage conditions for the expiration date.