NAVANE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for NAVANE (NAVANE).
Thioxanthene neuroleptic; blocks postsynaptic dopamine D1 and D2 receptors in the brain; also exhibits anticholinergic, alpha-adrenergic blocking, and sedative effects.
| Metabolism | Hepatic via CYP450 enzymes (primarily CYP2D6, with minor contributions from CYP1A2, CYP3A4). |
| Excretion | Primarily hepatic metabolism; approximately 20-30% excreted renally as metabolites, <1% unchanged. Biliary/fecal excretion accounts for ~50% of metabolites. |
| Half-life | Terminal elimination half-life is approximately 20-24 hours, allowing for once-daily dosing. Steady-state reached in 4-5 days. |
| Protein binding | >99% bound, primarily to albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | 10-15 L/kg, indicating extensive tissue distribution and high lipophilicity. |
| Bioavailability | Oral: ~30-40% due to first-pass metabolism; IM: 100%. |
| Onset of Action | Oral: 30-60 minutes; IM: 15-30 minutes. |
| Duration of Action | Oral: 12-24 hours; IM: 24-48 hours. Clinical effects may persist longer due to active metabolites. |
| Molecular Weight | 443.63 |
Oral: 10-20 mg three times daily; maximum 160 mg/day. IM (acute): 5-10 mg every 4-6 hours; maximum 30 mg/day.
| Dosage form | CONCENTRATE |
| Renal impairment | No specific guidelines; use caution in severe impairment (GFR <30 mL/min) with 50% dose reduction. |
| Liver impairment | Child-Pugh A: no adjustment. Child-Pugh B: reduce dose by 50%. Child-Pugh C: avoid use. |
| Pediatric use | Not recommended for use in children; safety and efficacy not established. |
| Geriatric use | Initiate at 5 mg/day with gradual titration; monitor for hypotension and extrapyramidal symptoms. |
| 1st trimester | First trimester exposure associated with congenital malformations (e.g., neural tube defects) in animal studies; human data limited but caution advised. |
| 2nd trimester | Second trimester use may be considered if benefit outweighs risk; monitor for extrapyramidal symptoms in newborn. |
| 3rd trimester | Third trimester use may cause neonatal extrapyramidal symptoms, withdrawal, or sedation; avoid or use with caution. |
Clinical note
Comprehensive clinical and safety monograph for NAVANE (NAVANE).
| Placental transfer | Thiothixene crosses the placenta; animal studies show fetal transfer. Human data limited but placental passage is likely due to molecular size. |
| Breastfeeding | Navane (thiothixene) is excreted into breast milk in low amounts; minimal infant exposure expected. However, monitor infant for sedation or extrapyramidal effects. Use only if clearly needed. |
■ FDA Black Box Warning
Increased mortality in elderly patients with dementia-related psychosis; risk of fatal stroke.
| Serious Effects |
Hypersensitivity to thiothixene or any component of the formulationComatose statesCNS depression due to alcohol or other depressants
| Precautions | Tardive dyskinesia risk with prolonged use, Neuroleptic malignant syndrome (NMS), QT prolongation and arrhythmias, Orthostatic hypotension, Leukopenia, neutropenia, agranulocytosis, Seizure threshold lowering, Anticholinergic effects (constipation, urinary retention, blurred vision), Hyperprolactinemia |
| Food/Dietary | Avoid grapefruit and grapefruit juice as they may increase serum levels of thiothixene. No other significant food interactions identified. |
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| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | Pregnancy Category C. First trimester: Risk of congenital malformations not established; animal studies show fetal harm. Second and third trimesters: Neonates exposed late in pregnancy may exhibit extrapyramidal symptoms, jaundice, and hyperbilirubinemia. Maternal seizures may occur if drug withdrawn abruptly. |
| Fetal Monitoring | Monitor maternal blood pressure, liver function tests, and signs of extrapyramidal symptoms. In neonate, monitor for extrapyramidal symptoms, jaundice, hyperbilirubinemia, and sedation. |
| Fertility Effects | May cause amenorrhea, galactorrhea, and gynecomastia due to prolactin elevation. May impair fertility in women; reversible upon discontinuation. Effect on male fertility not well documented. |
| Clinical Pearls | NAVANE (thiothixene) is a typical antipsychotic with high potency and low anticholinergic burden, useful for negative symptoms of schizophrenia. Monitor for extrapyramidal symptoms (EPS) and tardive dyskinesia; consider anticholinergic agents for acute dystonia. Use with caution in elderly with dementia-related psychosis due to increased mortality risk. |
| Patient Advice | Take exactly as prescribed; do not adjust dose without consulting your doctor. · May cause drowsiness or dizziness; avoid driving or operating machinery until you know how it affects you. · Report any involuntary muscle movements, stiffness, or tremors to your doctor immediately. · Avoid alcohol and marijuana; they can increase side effects like drowsiness and dizziness. · Do not stop abruptly; your doctor will taper the dose to prevent withdrawal symptoms. · Inform all healthcare providers you are taking this medication. · If you become pregnant or plan to breastfeed, discuss with your doctor. |