TRIFLUOPERAZINE HYDROCHLORIDE
Clinical safety rating: safe
Animal studies have demonstrated safety
Trifluoperazine is a typical antipsychotic of the phenothiazine class. It blocks postsynaptic dopamine D1 and D2 receptors in the mesolimbic system, reducing dopaminergic neurotransmission. It also has antiemetic effects via dopamine blockade in the chemoreceptor trigger zone and possesses anticholinergic, antihistaminergic, and alpha-adrenergic blocking properties.
| Metabolism | Hepatic metabolism primarily via N-demethylation, N-oxidation, and sulfoxidation; minor involvement of CYP450 isoenzymes (CYP1A2, CYP2D6, CYP3A4). |
| Excretion | Primarily renal (approximately 70% as metabolites, <1% unchanged); fecal (approximately 30% via bile) |
| Half-life | Terminal elimination half-life: 12–24 hours; clinical context: requires 5–7 days to reach steady state; may be prolonged in elderly or hepatic impairment |
| Protein binding | 90–99% bound, primarily to albumin and alpha-1 acid glycoprotein |
| Volume of Distribution | 9–18 L/kg; indicates extensive tissue distribution with high lipophilicity |
| Bioavailability | Oral: approximately 50% (range 30–70%) due to first-pass metabolism; intramuscular: 100% |
| Onset of Action | Oral: 30–60 minutes; intramuscular: 15–30 minutes; immediate-release oral: within 1 hour |
| Duration of Action | Oral: 6–12 hours for antipsychotic effect; sustained-release formulations: 12–24 hours; clinical notes: residual effects may persist beyond 24 hours due to slow elimination |
5-10 mg orally twice daily (maximum 40 mg/day), or 1-2 mg intramuscularly every 4-6 hours for acute symptoms (maximum 10 mg/day).
| Dosage form | TABLET |
| Renal impairment | No specific dose adjustment recommended; use with caution in severe renal impairment (CrCl <10 mL/min) due to potential accumulation. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: avoid use. |
| Pediatric use | Children 6-12 years: 1-5 mg/day orally in divided doses; maximum 15 mg/day. Not recommended for children under 6 years. |
| Geriatric use | Initial dose: 1-2 mg orally twice daily; increase slowly due to increased sensitivity to extrapyramidal effects and hypotension. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
CNS depressants may enhance sedative effects Can cause extrapyramidal symptoms and neuroleptic malignant syndrome.
| Breastfeeding | Trifluoperazine is excreted into breast milk at low concentrations; estimated relative infant dose is <1% of maternal weight-adjusted dose. M/P ratio not established. Use with caution, monitor infant for sedation and extrapyramidal effects. ACOG recommends avoiding antipsychotics during breastfeeding if possible. |
| Teratogenic Risk | First trimester: Risk of limb reduction defects and other malformations based on case reports and retrospective studies. Second and third trimesters: Risk of extrapyramidal symptoms and withdrawal in neonates (e.g., agitation, hypertonia, tremor). |
■ FDA Black Box Warning
Increased mortality in elderly patients with dementia-related psychosis; risk of death is primarily due to cardiovascular or infectious events.
| Common Effects | Extrapyramidal symptoms |
| Serious Effects |
["Hypersensitivity to trifluoperazine or any component","Comatose or severely depressed states","Bone marrow suppression","Concomitant use with high doses of CNS depressants (e.g., alcohol, barbiturates)","Prolonged QT interval or history of cardiac arrhythmias","Pediatric patients with conditions associated with Reye's syndrome-like symptoms"]
| Precautions | ["Elderly with dementia-related psychosis: increased mortality","Tardive dyskinesia: risk increases with cumulative dose and duration; may be irreversible","Neuroleptic malignant syndrome (NMS): potentially fatal; discontinue if signs/symptoms develop","Leukopenia, neutropenia, agranulocytosis: reported; monitor CBCs during prolonged therapy","QT prolongation: avoid with other drugs that prolong QT or electrolyte disturbances","Seizures: may lower seizure threshold; use cautiously in patients with epilepsy","Anticholinergic effects: use cautiously in patients with prostatic hypertrophy, glaucoma, or myasthenia gravis","Hepatic effects: jaundice and liver injury reported; discontinue if liver function tests increase","Hyperprolactinemia: may cause galactorrhea, gynecomastia, sexual dysfunction","Photosensitivity: avoid excessive sun exposure"] |
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| Fetal Monitoring | Maternal: Monitor for extrapyramidal symptoms, tardive dyskinesia, blood pressure, and liver function. Fetal/neonatal: Ultrasound for limb anomalies in first trimester if exposed; monitor neonate for extrapyramidal symptoms, withdrawal, and respiratory depression. |
| Fertility Effects | Trifluoperazine may elevate prolactin levels, potentially causing menstrual irregularities, galactorrhea, and impaired fertility in women. In men, hyperprolactinemia can lead to decreased libido and erectile dysfunction. Effects are reversible upon discontinuation. |