PERMITIL
Clinical safety rating: caution
Comprehensive clinical and safety monograph for PERMITIL (PERMITIL).
Antagonist at dopamine D2 receptors, also blocks alpha-1 adrenergic, histaminergic, and muscarinic receptors.
| Metabolism | Primarily hepatic via CYP2D6; minor contributions from CYP1A2, CYP3A4. |
| Excretion | Renal: <1% unchanged; Hepatic: extensively metabolized, metabolites excreted in urine (50-60%) and feces (30-40%) |
| Half-life | Terminal elimination half-life: 20-30 hours; clinically, steady-state achieved in 5-7 days; prolonged in elderly and hepatic impairment |
| Protein binding | 90-95% bound to albumin and alpha-1-acid glycoprotein |
| Volume of Distribution | 12-18 L/kg; high Vd indicates extensive tissue distribution (e.g., brain, lungs) |
| Bioavailability | Oral: 40-60% (extensive first-pass metabolism); IM: 70-80% |
| Onset of Action | Oral: 30-60 minutes; IM: 15-30 minutes; IV: 5-10 minutes |
| Duration of Action | Oral: 4-6 hours; IM: 4-6 hours; IV: 3-4 hours; clinical effects (e.g., antipsychotic) persist with repeated dosing |
| Molecular Weight | 437.52 |
2.5-10 mg orally every 8-12 hours; maximum 40 mg/day. For severe psychosis: initial 10 mg IM, then 5-10 mg IM every 6-8 hours; maximum 30 mg/day IM.
| Dosage form | TABLET |
| Renal impairment | No specific dose adjustment recommended; use with caution in severe renal impairment (eGFR <10 mL/min). |
| Liver impairment | Child-Pugh A: reduce dose by 25-50%; Child-Pugh B: reduce dose by 50-75%; Child-Pugh C: avoid or use lowest possible dose with close monitoring. |
| Pediatric use | Children 6-12 years: 0.25-3.5 mg/day orally in divided doses; not recommended for children <6 years. IM: 0.01-0.03 mg/kg every 6-8 hours (max 1 mg/dose). |
| Geriatric use | Initial dose 0.5-1 mg orally once daily; titrate slowly by 0.5-1 mg increments; usual maintenance 1-5 mg daily; lower doses due to increased sensitivity and risk of adverse effects. |
| 1st trimester | Avoid if possible; risk of teratogenicity (limb malformations) with first trimester exposure. |
| 2nd trimester | Use only if benefit outweighs risk; monitor for maternal hypotension and neonatal extrapyramidal symptoms. |
| 3rd trimester | Avoid near term due to risk of neonatal extrapyramidal symptoms, jaundice, and prolonged QT interval. |
Clinical note
Comprehensive clinical and safety monograph for PERMITIL (PERMITIL).
| Placental transfer | Crosses placenta; detected in cord blood; potential for neonatal effects. |
| Breastfeeding | Enters breast milk in low amounts; monitor infant for sedation, extrapyramidal symptoms, and poor feeding; manufacturer advises caution. |
| Lactation Rating |
■ FDA Black Box Warning
Increased mortality in elderly patients with dementia-related psychosis.
| Serious Effects |
Comatose statesCNS depressionBlood dyscrasiasPheochromocytomaHypersensitivity to phenothiazines
| Precautions | Tardive dyskinesia, Neuroleptic malignant syndrome, QT prolongation, Hyperglycemia, Orthostatic hypotension |
| Food/Dietary | Avoid excessive caffeine or grapefruit juice. Maintain adequate hydration to prevent constipation. No specific food-drug interactions documented; however, alcohol may exacerbate CNS depression and hypotension. |
| Clinical Pearls |
Loading safety data…
| L3 (Moderately Safe - moderate risk of adverse effects; use if benefit outweighs risk). |
| Teratogenic Risk | First trimester: Limited human data; animal studies show no consistent teratogenicity. Use only if benefit outweighs risk. Second/third trimester: Risk of extrapyramidal symptoms and withdrawal in neonates (e.g., abnormal muscle movements, agitation, poor feeding). Avoid in high doses near term due to potential for neonatal jaundice. |
| Fetal Monitoring | Maternal: Baseline and periodic liver function tests, CBC, and ECG (if high doses or prolonged use). Monitor for extrapyramidal symptoms, tardive dyskinesia, and neuroleptic malignant syndrome. Fetal/neonatal: Ultrasound for fetal growth; neonatal observation for extrapyramidal symptoms, jaundice, and feeding difficulties. |
| Fertility Effects | May cause hyperprolactinemia, leading to menstrual irregularities, anovulation, and galactorrhea, potentially reducing fertility. Impact is reversible upon dose reduction or discontinuation. |
| PERMITIL (fluphenazine) is a high-potency first-generation antipsychotic. Use cautiously in elderly patients with dementia-related psychosis due to increased mortality risk. Monitor for extrapyramidal symptoms (EPS), tardive dyskinesia, neuroleptic malignant syndrome (NMS), and QT prolongation. Start at low doses (e.g., 2.5-10 mg/day oral) and titrate slowly. Depot formulations (decanoate) require strict adherence to injection schedules. Avoid concurrent use with other QT-prolonging drugs. |
| Patient Advice | Take exactly as prescribed; do not stop abruptly without consulting your doctor. · May cause drowsiness; avoid driving or operating machinery until you know how this medicine affects you. · Report any involuntary muscle movements, stiffness, fever, or altered mental status immediately. · Avoid alcohol and cannabis; they may worsen side effects. · Regular blood tests and ECGs may be needed to monitor for side effects. · Do not double the dose if you miss one; contact your doctor for guidance. |