STELAZINE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for STELAZINE (STELAZINE).
Antipsychotic agent; blocks postsynaptic dopamine D1 and D2 receptors in the brain; also exhibits anticholinergic, alpha-adrenergic, and antihistaminergic effects.
| Metabolism | Hepatic via CYP450 enzymes (primarily CYP2D6); also undergoes N-demethylation and sulfoxidation. |
| Excretion | Primarily renal (metabolites and unchanged drug; ~50% as metabolites); biliary/fecal excretion accounts for <20%. |
| Half-life | Terminal elimination half-life is approximately 24-30 hours (up to 40 hours in chronic use). Clinical context: Steady-state is reached in 5-7 days; allows once- or twice-daily dosing. |
| Protein binding | 92-97% bound to albumin and alpha-1 acid glycoprotein. |
| Volume of Distribution | Approximately 18-30 L/kg (0.5-1.5 L/kg). Clinical meaning: Extensive tissue distribution with high CNS penetration. |
| Bioavailability | Oral: ~40% (due to first-pass metabolism); IM: 100%. |
| Onset of Action | Oral: 30-60 minutes; IM: 15-30 minutes; IV: 5-10 minutes. Antipsychotic effect may take days to weeks. |
| Duration of Action | Oral: 4-6 hours for single dose (antipsychotic effect persists longer); IM/IV: 4-6 hours. Clinical note: Extrapyramidal effects may outlast therapeutic effect. |
Adults: 2-10 mg orally twice daily; maximum 40 mg/day.
| Dosage form | INJECTABLE |
| Renal impairment | No specific dose adjustment recommended; use caution in severe renal impairment. |
| Liver impairment | Child-Pugh A: no adjustment. Child-Pugh B: reduce dose by 50%. Child-Pugh C: avoid use or reduce dose by 75%. |
| Pediatric use | Children 6-12 years: 1 mg 1-2 times daily; increase gradually up to 15 mg/day. Children >12 years: adult dosing. |
| Geriatric use | Initiate at 1-2 mg twice daily; titrate slowly due to increased sensitivity and risk of orthostatic hypotension and extrapyramidal symptoms. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for STELAZINE (STELAZINE).
| Breastfeeding | Excreted in breast milk in small amounts; relative infant dose est. ~0.1-0.5% of maternal weight-adjusted dose. M/P ratio not established. Monitor infant for sedation, EPS, and poor feeding. Generally considered compatible with breastfeeding with caution. |
| Teratogenic Risk | First trimester: Limited data; possible increased risk of congenital malformations (neural tube defects, cardiovascular) based on some retrospective studies. Second/third trimesters: Risk of extrapyramidal symptoms, jaundice, and hyperreflexia in neonates with late exposure. Case reports of neonatal withdrawal and EPS. Not a known major teratogen but use only if benefits outweigh risks. |
■ FDA Black Box Warning
Increased mortality in elderly patients with dementia-related psychosis.
| Serious Effects |
Comatose states, CNS depression (e.g., barbiturates, alcohol), bone marrow depression, blood dyscrasias, hepatic disease, hypersensitivity to phenothiazines.
| Precautions | Tardive dyskinesia, neuroleptic malignant syndrome, QT prolongation, leukopenia/neutropenia/agranulocytosis, seizure threshold lowering, anticholinergic effects, hypotension, cholestatic jaundice, ocular changes (corneal/lenticular deposits). |
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| Fetal Monitoring | Maternal: Baseline and periodic LFTs, CBC, EKG (QTc), blood glucose, and weight. Monitor for EPS and tardive dyskinesia. Fetal: Third trimester ultrasound for growth; neonatal monitoring for EPS, jaundice, and neurobehavioral issues at birth. |
| Fertility Effects | May cause hyperprolactinemia, leading to menstrual irregularities, anovulation, and reduced fertility in females. Reversible upon discontinuation. In males, possible decreased libido and erectile dysfunction. No known effect on spermatogenesis. |