Medication Name/Class
- Generic/Brand: Fluphenazine / Prolixin Decanoate
- Class: First-Generation Antipsychotic (Phenothiazine)
2. Mechanism of Action
- Blocks postsynaptic D2 (dopamine) receptors in the mesolimbic system.
- Possesses weak anticholinergic and alpha1-adrenergic blocking effects.
- Strong D2 blockade reduces psychosis but directly causes extrapyramidal symptoms (EPS).
3. Expected Action/Therapeutic Effect
- Decreases dopamine neurotransmission to control psychotic symptoms.
- Provides antiemetic effects by blocking the chemoreceptor trigger zone.
4. Indications
- Priority Uses: Schizophrenia (maintenance and acute management).
- Acute agitation in psychotic disorders.
- Off-Label: Severe behavioral/psychological symptoms of dementia (strictly regulated by OBRA).
5. Pharmacokinetics
- Onset/Peak: Oral peaks in 2 hrs. Immediate IM peaks in 1.5-2 hrs. Depot IM/SubQ peaks in 8-10 hrs.
- Duration: Immediate IM lasts 6-8 hrs; Depot lasts 2-4 weeks.
- Metabolism: Liver; major CYP2D6 substrate and inhibitor.
6. Drug-Drug Interactions
- CNS depressants: Increase sedation and fall risk in the elderly.
- CYP2D6 substrates: Metabolism may be inhibited by fluphenazine.
- Food/Liquid Interaction: Oral concentrate MUST NOT be mixed with caffeine (coffee, cola), tannics (tea), or pectinates (apple juice).
7. Side Effects vs Adverse Effects
- Common: EPS (pseudoparkinsonism, akathisia, dystonia), sedation, anticholinergic effects (dry mouth), orthostatic hypotension.
- Severe/Life-Threatening: Neuroleptic Malignant Syndrome (NMS), Tardive Dyskinesia (TD), prolonged QT/Torsade de pointes, agranulocytosis, seizures.
8. Contraindications/Precautions
- Contraindicated: Hepatic impairment or liver damage.
- Precautions: Geriatric patients (Beers Criteria) due to high risk of falls, fractures, and anticholinergic effects.
9. Nursing Interventions
- Admin: Inject deeply into upper outer gluteal muscle; rotate sites. Do NOT dilute depot injections.
- Safety: Keep patient recumbent for 30 mins post-injection to minimize severe hypotension.
- Monitor: Sodium levels for SIADH risk.
10. Patient Education
- Take oral doses with food if GI upset occurs.
- Avoid spilling liquid preparations on skin/clothing.
- Rise slowly from sitting or lying down to manage orthostatic hypotension.
11. Black Box Warning/Antidote
- BBW: Increased mortality in elderly patients with dementia-related psychosis (deaths usually from heart failure, infections, or stroke).
12. Nursing School Priority Summary
- Must Know: Keep the patient flat for 30 minutes after injection to prevent severe hypotensive effects.
- Nice to Know: 10 mg of daily oral fluphenazine converts to ~12.5 mg of depot every 3 weeks.
- Test Trap: The oral concentrate has strict mixing rules—never mix with coffee, tea, or apple juice.
- Clinical Red Flag: Watch for potentially fatal NMS, TD, and blood dyscrasias.