Drug Guide
Fluvoxamine Maleate
Classification
Therapeutic: Selective Serotonin Reuptake Inhibitor (SSRI)
Pharmacological: Serotonin reuptake inhibitor
FDA Approved Indications
- Obsessive-Compulsive Disorder (OCD)
- Major Depressive Disorder (MDD)
Mechanism of Action
Fluvoxamine inhibits the reuptake of serotonin (5-HT) into presynaptic neurons, increasing serotonergic activity in the central nervous system.
Dosage and Administration
Adult: Typically 50 mg once daily, adjustable up to 300 mg/day based on response and tolerability.
Pediatric: Not FDA approved for pediatric use.
Geriatric: Start at a lower dose, such as 25 mg daily, and titrate as needed, considering comorbidities.
Renal Impairment: Use with caution; dosage adjustment may be necessary.
Hepatic Impairment: Start at a lower dose; monitor closely.
Pharmacokinetics
Absorption: Well absorbed after oral administration.
Distribution: Widely distributed; about 98% protein-bound.
Metabolism: Primarily hepatic via CYP450 enzymes, mainly CYP2D6, CYP3A4.
Excretion: Excreted mainly in urine as metabolites, with some fecal elimination.
Half Life: Approximately 15-26 hours.
Contraindications
- Concomitant use with monoamine oxidase inhibitors (MAOIs).
- Known hypersensitivity to fluvoxamine.
Precautions
- Use cautiously in patients with hepatic impairment.
- Monitor for serotonin syndrome.
- Assess for suicidal ideation, especially during initial therapy.
Adverse Reactions - Common
- Nausea (Common)
- Insomnia (Common)
- Somnolence (Common)
- Dry mouth (Common)
Adverse Reactions - Serious
- Serotonin syndrome (Rare)
- Suicidal ideation (Monitor closely)
- Hyponatremia (Rare)
- Bleeding risk (Rare)
Drug-Drug Interactions
- Increased serotonergic effects with other SSRIs, SNRIs, triptans, linezolid, tramadol.
- CYP450 interactions with drugs metabolized by CYP1A2, CYP2D6.
- Potential for QT prolongation with other medications affecting QT interval.
Drug-Food Interactions
- Alcohol may increase sedation and risk of side effects.
Drug-Herb Interactions
- St. John’s Wort, which can increase serotonin levels, may increase risk of serotonin syndrome.
Nursing Implications
Assessment: Monitor for signs of serotonin syndrome, suicidality, and effectiveness of therapy.
Diagnoses:
- Risk for serotonin syndrome.
- Impaired social interaction related to obsessive-compulsive behaviors.
Implementation: Administer as prescribed, typically once daily.
Evaluation: Assess reduction in OCD symptoms and depression; monitor for adverse effects.
Patient/Family Teaching
- Take medication exactly as prescribed.
- Report side effects such as agitation, hallucinations, or abnormal bleeding.
- Avoid alcohol and other CNS depressants.
- Do not discontinue abruptly to prevent withdrawal symptoms.
Special Considerations
Black Box Warnings:
- Increased risk of suicidal thoughts and behavior in children, adolescents, and young adults.
- Serotonin syndrome when combined with other serotonergic drugs.
Genetic Factors: CYP2D6 poor metabolizers may experience increased drug levels.
Lab Test Interference: Potential false elevation of blood cortisol levels.
Overdose Management
Signs/Symptoms: Nausea, vomiting, tremors, agitation, seizures, serotonin syndrome.
Treatment: Supportive care; activated charcoal if within 1 hour of ingestion; benzodiazepines for agitation or seizures; specific antidote is not available.
Storage and Handling
Storage: Store at room temperature, 20°C to 25°C (68°F to 77°F).
Stability: Stable under proper storage; check expiration date regularly.