Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ONFI vs STELAZINE
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
GABA-A receptor positive allosteric modulator; increases the frequency of chloride channel opening in response to GABA.
Antipsychotic agent; blocks postsynaptic dopamine D1 and D2 receptors in the brain; also exhibits anticholinergic, alpha-adrenergic, and antihistaminergic effects.
Treatment of seizures associated with Lennox-Gastaut syndrome,Adjunctive therapy for other seizure types
Schizophrenia,Short-term treatment of generalized non-psychotic anxiety (off-label)
Initial: 10 mg orally twice daily; may increase by 10 mg/day after 1 week to maintenance of 20–40 mg/day in two divided doses. Maximum: 60 mg/day.
Adults: 2-10 mg orally twice daily; maximum 40 mg/day.
The terminal elimination half-life of clobazam is 36–42 hours. The active metabolite N-desmethylclobazam has a half-life of 71–82 hours. The long half-life permits once-daily dosing but also leads to slow accumulation; steady-state is achieved after 2–3 weeks.
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.
Hepatic via CYP3A4 and CYP2C19; primary metabolite N-desmethylclobazam is active.
Hepatic via CYP450 enzymes (primarily CYP2D6); also undergoes N-demethylation and sulfoxidation.
Clobazam (ONFI) undergoes extensive hepatic metabolism. Approximately 82% of the dose is eliminated in urine (as unchanged drug and metabolites) and about 11% in feces. Unchanged clobazam accounts for <1% of urinary excretion. The major metabolite, N-desmethylclobazam, is excreted primarily renally.
Primarily renal (metabolites and unchanged drug; ~50% as metabolites); biliary/fecal excretion accounts for <20%.
Clobazam is approximately 80–90% bound to plasma proteins, primarily albumin.
92-97% bound to albumin and alpha-1 acid glycoprotein.
The apparent volume of distribution is approximately 100 L (range 77–120 L), or roughly 1.4 L/kg. This large Vd indicates extensive tissue distribution and accumulation in fatty tissues.
Approximately 18-30 L/kg (0.5-1.5 L/kg). Clinical meaning: Extensive tissue distribution with high CNS penetration.
Oral bioavailability is nearly complete (>90%). Clobazam is well absorbed after oral administration with only minor first-pass metabolism.
Oral: ~40% (due to first-pass metabolism); IM: 100%.
No specific GFR-based dose adjustments; use with caution in severe impairment (Cr Cl < 30 m L/min) due to potential for increased sedation.
No specific dose adjustment recommended; use caution in severe renal impairment.
Mild to moderate (Child-Pugh A/B): Initial 5 mg orally twice daily; may increase by 5 mg/day after 1 week to maximum 20 mg/day. Severe (Child-Pugh C): Not recommended.
Child-Pugh A: no adjustment. Child-Pugh B: reduce dose by 50%. Child-Pugh C: avoid use or reduce dose by 75%.
Clobazam (ONFI) for seizures: Age 2 to <6 years, body weight ≥12.5 kg: Initial 5 mg orally once daily; titrate to maintenance 5 mg twice daily. Age ≥6 years: Weight ≤30 kg: Initial 5 mg once daily; titrate to 5 mg twice daily (max 20 mg/day). Weight >30 kg: same as adult dosing. Administer with food.
Children 6-12 years: 1 mg 1-2 times daily; increase gradually up to 15 mg/day. Children >12 years: adult dosing.
Elderly (≥65 years): Initial 5 mg orally twice daily; increase slowly to lowest effective maintenance due to increased sensitivity and risk of falls. Avoid doses above 20 mg/day unless clearly necessary.
Initiate at 1-2 mg twice daily; titrate slowly due to increased sensitivity and risk of orthostatic hypotension and extrapyramidal symptoms.
Concomitant use with opioids may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant use for patients for whom alternative treatment options are inadequate.
Increased mortality in elderly patients with dementia-related psychosis.
Risk of respiratory depression, especially with opioids,Sedation and somnolence,Risk of abuse and dependence,Withdrawal seizures on abrupt discontinuation,Increased risk of suicidal thoughts or behavior
Tardive dyskinesia, neuroleptic malignant syndrome, QT prolongation, leukopenia/neutropenia/agranulocytosis, seizure threshold lowering, anticholinergic effects, hypotension, cholestatic jaundice, ocular changes (corneal/lenticular deposits).
Hypersensitivity to clobazam or any component of formulation,Severe hepatic impairment
Comatose states, CNS depression (e.g., barbiturates, alcohol), bone marrow depression, blood dyscrasias, hepatic disease, hypersensitivity to phenothiazines.
Avoid grapefruit and grapefruit juice as they may increase clobazam levels. No other significant food interactions are known. CNS depressant effects may be potentiated by alcohol.
Avoid alcohol and CNS depressants. Grapefruit juice may increase drug levels; avoid concurrent use. Limit caffeine intake. No specific dietary restrictions, but monitor weight gain due to increased appetite.
Pregnancy Category C. First trimester: increased risk of major malformations including cleft lip/palate (OR 2.0-3.0); second/third trimester: risk of neonatal withdrawal, hypotonia, poor feeding, respiratory depression, and hypothermia; consistent exposure may cause floppy infant syndrome. Late pregnancy exposure linked to neonatal benzodiazepine withdrawal syndrome.
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.
Clobazam is excreted into breast milk; M/P ratio approximately 0.5-0.6. Accumulation possible in neonates; monitor for sedation, poor feeding, apnea. Avoid if infant has impaired hepatic function or low birth weight. American Academy of Pediatrics recommends caution; use lowest effective maternal dose.
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.
Increased clearance during pregnancy (CYP3A4 induction); plasma concentrations may decrease by 30-50% in third trimester. Dose adjustments often required: monitor therapeutic response and consider dose increase by 50-100% in late pregnancy; postpartum reduce to prepregnancy dose over 1-2 weeks to avoid toxicity.
Increased clearance in pregnancy may necessitate dose titration. Start at low end of dosing range; increase gradually based on response and tolerability. Monitor for relapse. Postpartum dose may need reduction due to restored clearance. No specific PK studies available; clinical judgment advised.
ONFI (clobazam) is a benzodiazepine indicated for seizures associated with Lennox-Gastaut syndrome. Titrate slowly to minimize sedation. Monitor for withdrawal symptoms upon discontinuation; taper over several weeks. Not recommended for use in patients with severe hepatic impairment (Child-Pugh C). For patients on other CNS depressants, consider dose reduction. Clobazam's active metabolite, N-desmethylclobazam, has a long half-life (36-46 hours) and can accumulate, especially in poor CYP2C19 metabolizers. In such patients, consider lower doses and monitor for excessive sedation.
Extrapyramidal symptoms (EPS) are common; use benztropine prophylactically in young males. Monitor for QT prolongation, especially in elderly. Avoid in patients with history of tardive dyskinesia. Can cause orthostatic hypotension; titrate slowly. Neuroleptic malignant syndrome (NMS) rare but serious; discontinue immediately if hyperthermia, rigidity, autonomic instability occur.
Take ONFI exactly as prescribed; do not stop suddenly as withdrawal seizures may occur.,Avoid alcohol and other sedatives while taking this medication due to increased risk of drowsiness and respiratory depression.,Report any unusual mood changes, depression, or suicidal thoughts to your healthcare provider.,Do not drive or operate heavy machinery until you know how ONFI affects you, as it can cause dizziness and drowsiness.,If you are pregnant, planning to become pregnant, or breastfeeding, discuss with your doctor before using ONFI.,Store at room temperature, away from moisture and heat.
Take exactly as prescribed; do not stop abruptly.,May cause dizziness upon standing; rise slowly from sitting or lying down.,Report any involuntary muscle movements, stiffness, or tremors to your doctor.,Avoid alcohol and other central nervous system depressants.,May cause drowsiness; use caution when driving or operating machinery.,Notify your doctor if you experience rapid heartbeat, fainting, or fever with muscle rigidity.,Avoid exposure to extreme heat (can impair body temperature regulation).,Store at room temperature away from light and moisture.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about ONFI vs STELAZINE, answered by our medical review team.
ONFI is a Benzodiazepine Anticonvulsant that works by GABA-A receptor positive allosteric modulator; increases the frequency of chloride channel opening in response to GABA.. STELAZINE is a Phenothiazine Antipsychotic that works by Antipsychotic agent; blocks postsynaptic dopamine D1 and D2 receptors in the brain; also exhibits anticholinergic, alpha-adrenergic, and antihistaminergic effects.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ONFI and STELAZINE depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of ONFI is: Initial: 10 mg orally twice daily; may increase by 10 mg/day after 1 week to maintenance of 20–40 mg/day in two divided doses. Maximum: 60 mg/day.. The standard adult dose of STELAZINE is: Adults: 2-10 mg orally twice daily; maximum 40 mg/day.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between ONFI and STELAZINE in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. ONFI is classified as Category C. Pregnancy Category C. First trimester: increased risk of major malformations including cleft lip/palate (OR 2.0-3.0); second/third trimester: risk of neonatal withdrawal, hypotonia. STELAZINE is classified as Category C. First trimester: Limited data; possible increased risk of congenital malformations (neural tube defects, cardiovascular) based on some retrospective studies. Second/third trimester. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.