Clinical Overview
Fluphenazine is a typical antipsychotic available in both oral and long-acting injectable formulations, indicated for the treatment of schizophrenia and other psychotic disorders. The decanoate injection provides sustained antipsychotic effect for 2-4 weeks, making it valuable for patients with medication adherence issues.
Primary Clinical Applications
Fluphenazine is effective for positive symptoms of schizophrenia including hallucinations, delusions, and thought disorders. The long-acting injectable form is particularly useful for maintenance therapy in patients with poor medication compliance or those who prefer less frequent dosing.
Mechanism and Clinical Profile
As a phenothiazine antipsychotic, fluphenazine blocks dopamine D2 receptors in the brain, particularly in the mesolimbic pathway. It has high potency with relatively low sedation but higher risk of extrapyramidal side effects compared to low-potency typical antipsychotics.
Formulation Advantages
The availability of both oral and depot formulations allows for flexible treatment approaches. The decanoate injection ensures medication delivery and can improve long-term outcomes in patients with chronic schizophrenia who struggle with daily oral medication adherence.
Prescribing Information
Dosing & Administration
Schizophrenia – Oral (Adults):
- Initial: 2.5-10 mg daily in divided doses (every 6-8 hours)
- Maintenance: 1-5 mg daily
- Maximum: 40 mg daily
Fluphenazine Decanoate (IM):
- Initial: 12.5-25 mg IM every 3-4 weeks
- Maintenance: 12.5-100 mg every 2-5 weeks
- Conversion: 20 mg oral daily ≈ 25 mg decanoate every 3 weeks
Elderly:
- Initial: 1-2.5 mg daily, titrate slowly
Indications
- Treatment of schizophrenia and other psychotic disorders
- Management of manifestations of psychotic disorders
Contraindications
- Hypersensitivity to phenothiazines
- Severe CNS depression or comatose states
- Blood dyscrasias
- Liver damage
- Subcortical brain damage
Warnings & Precautions
- Boxed Warning: Increased mortality in elderly patients with dementia-related psychosis
- Tardive dyskinesia: Risk increases with duration of treatment
- Neuroleptic malignant syndrome: Rare but potentially fatal
- Extrapyramidal symptoms: High incidence with high-potency antipsychotics
- QT prolongation: Monitor ECG in patients with cardiac risk factors
- Hypotension: Particularly with parenteral administration
Drug Interactions
- CNS depressants: Enhanced sedation and respiratory depression
- Anticholinergics: Increased anticholinergic effects
- Lithium: Increased risk of extrapyramidal symptoms
- QT-prolonging drugs: Additive cardiac effects
Adverse Reactions
Common:
- Extrapyramidal symptoms (dystonia, akathisia, parkinsonism)
- Drowsiness, dizziness, dry mouth
Serious:
- Tardive dyskinesia, neuroleptic malignant syndrome
- Agranulocytosis, liver toxicity
Injection Site (Decanoate):
- Pain, swelling, nodule formation
Special Populations
- Elderly: Increased mortality risk in dementia-related psychosis
- Hepatic Impairment: Use with caution, may require dose reduction
- Pregnancy: Category C – use only if benefits outweigh risks
- Depot Administration: Requires healthcare provider administration and monitoring
Medical Disclaimer: This information is for educational purposes only and is not intended as medical advice. Always consult with qualified healthcare professionals before making any treatment decisions. Individual patient circumstances may vary significantly.
