Drug Guide
Fluphenazine Decanoate
Classification
Therapeutic: Antipsychotic (typical/neuroleptic)
Pharmacological: Phenothiazine
FDA Approved Indications
- Schizophrenia
- Long-term treatment of chronic psychoses
Mechanism of Action
Blocks dopamine D2 receptors in the central nervous system, reducing psychotic symptoms.
Dosage and Administration
Adult: Typically 25-50 mg IM every 2 weeks, adjusted based on response.
Pediatric: Not generally used in children.
Geriatric: Use with caution; start at lower doses due to increased sensitivity.
Renal Impairment: Adjust dosing based on clinical response.
Hepatic Impairment: Use cautiously; no specific adjustments well-documented.
Pharmacokinetics
Absorption: Slow IM absorption; provides sustained release.
Distribution: Widely distributed in body tissues, crosses blood-brain barrier.
Metabolism: Liver metabolism primarily via CYP2D6; some conjugation.
Excretion: Primarily in urine as metabolites.
Half Life: Approximately 6-7 days, allowing every 2-week dosing.
Contraindications
- Coma or CNS depression from alcohol or CNS depressants.
- Bone marrow suppression.
Precautions
- History of neuroleptic malignant syndrome.
- Seizure disorder.
- Cautious use in Parkinson’s disease, cardiovascular disease, and in elderly patients with dementia-related psychosis.
Adverse Reactions - Common
- Extrapyramidal symptoms (Frequent)
- Dystonia (Common)
- Akathisia (Common)
- Sedation (Common)
- Weight gain (Common)
Adverse Reactions - Serious
- Neuroleptic malignant syndrome (Rare)
- Tardive dyskinesia (Rare)
- Blood dyscrasias (e.g., agranulocytosis) (Rare)
- QT prolongation and arrhythmias (Rare)
Drug-Drug Interactions
- CNS depressants
- Other QT-prolonging drugs
- Anticholinergics
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor mental status, extrapyramidal symptoms, vital signs, and cardiovascular status.
Diagnoses:
- Risk for falls due to sedation or orthostatic hypotension.
- Impaired physical mobility.
- Risk for neuroleptic malignant syndrome.
Implementation: Administer deep IM injection; monitor for adverse reactions; educate patient about symptoms to report.
Evaluation: Assess for reduction in psychotic symptoms and monitor for adverse effects.
Patient/Family Teaching
- Take medication exactly as prescribed.
- Report symptoms of extrapyramidal side effects, tardive dyskinesia, or neuroleptic malignant syndrome.
- Avoid alcohol and CNS depressants.
- Be cautious with dehydration and heat exposure.
Special Considerations
Black Box Warnings:
- Increased mortality in elderly patients with dementia-related psychosis.
- Risks of neuroleptic malignant syndrome.
Genetic Factors: CYP2D6 polymorphisms may affect metabolism.
Lab Test Interference: May cause false positives in certain assays.
Overdose Management
Signs/Symptoms: Extrapyramidal symptoms, hypotension, sedation, respiratory depression, seizures.
Treatment: Supportive care, manage hypotension with IV fluids, benzodiazepines for agitation, and general measures for overdose.
Storage and Handling
Storage: Store at controlled room temperature, 20-25°C (68-77°F).
Stability: Stable under proper storage conditions for the duration specified in the manufacturer’s package insert.