Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
SYMPAZAN vs VALTOCO
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
SYMPAZAN (clobazam) is a benzodiazepine that potentiates GABAergic inhibition via binding to the GABA-A receptor at the benzodiazepine site, enhancing chloride ion influx and neuronal hyperpolarization.
GABA-A receptor positive allosteric modulator; increases chloride ion conductance, hyperpolarizes neurons, and suppresses seizure activity.
FDA-approved for the treatment of seizures associated with Lennox-Gastaut syndrome (LGS) in patients aged 2 years and older,Off-label: adjunctive therapy for other epileptic syndromes, anxiety disorders, and acute repetitive seizures
Acute treatment of intermittent, stereotypic episodes of frequent seizure activity (i.e., seizure clusters, acute repetitive seizures) that are distinct from a patient's usual seizure pattern in patients with epilepsy aged 2 years and older
10-20 mg orally three times daily (maximum 60 mg/day). If switching from another benzodiazepine, use equivalent dose.
5 mg, 10 mg, 15 mg, or 20 mg intranasally as a single dose based on weight; for patients weighing <50 kg: 5 mg, 10 mg for 50-75 kg, 15 mg for 75-100 kg, 20 mg for >100 kg. In adults, maximum dose is 20 mg per seizure cluster.
Terminal elimination half-life is approximately 20-30 minutes sublingually, prolonged to 2-3 hours in hepatic impairment. Clinical context: Short t½ necessitates repeated dosing for seizure clusters.
Terminal elimination half-life: 15-17 hours (range 11-20 h) in adults; no dose adjustment for age or renal impairment is recommended, but clinical monitoring is prudent in hepatic impairment.
Primarily metabolized by CYP3A4 and CYP2C19 to N-desmethylclobazam, an active metabolite. N-desmethylclobazam is further metabolized by CYP2C19.
Hepatic via CYP3A4 and CYP2C9; active metabolite desmethyldiazepam (nordazepam)
Primarily renal excretion of unchanged drug (approximately 60-70%), with minor fecal elimination (10-15%) and metabolism.
Renal (70% as unchanged drug and metabolites, primarily glucuronide conjugate, with <2% as unchanged drug); biliary/fecal (30%)
Approximately 90-95% bound to albumin and alpha-1-acid glycoprotein.
96% bound, primarily to albumin
Vd is 1-2 L/kg, indicating extensive tissue distribution beyond plasma volume.
0.5-0.8 L/kg; approximates total body water, indicating extensive tissue distribution.
Sublingual and buccal: 100% bioequivalent to intravenous; intranasal: approximately 80%.
Intranasal: 75% (range 65-85%) relative to intravenous; rectal: 70-90% relative to intravenous.
No dose adjustment required for mild to moderate renal impairment. For severe renal impairment (Cr Cl <30 m L/min), use with caution and consider dose reduction; specific guidelines not established.
No dosage adjustment required for mild to moderate renal impairment. Severe renal impairment (e GFR <15 m L/min): consider using lower doses due to increased exposure; use with caution.
Contraindicated in severe hepatic impairment (Child-Pugh class C). For mild to moderate impairment (Child-Pugh A or B), reduce dose by 50% or administer with caution, as clobazam is extensively metabolized in the liver.
Child-Pugh A or B: no adjustment needed. Child-Pugh C: reduce dose by 50% due to increased diazepam exposure.
Based on body weight: 5 mg orally once daily for <30 kg, increase to 10 mg daily after 2 weeks if needed (max 20 mg/day). For ≥30 kg, 5-10 mg once daily initially, titrate to 20 mg/day (max 40 mg/day).
Age 6-17 years: 0.2 mg/kg intranasally, maximum single dose 20 mg. Administer as single dose per seizure cluster. Not recommended for children <6 years.
Initiate at 5 mg once daily, titrate slowly due to increased sensitivity to benzodiazepines and risk of falls. Maximum dose generally not to exceed 20 mg/day.
Elderly patients may have increased sensitivity; consider starting at lower end of dosing range (5-10 mg) and titrate based on response and tolerability. Use with caution due to risk of sedation and falls.
Concomitant use of benzodiazepines with opioids may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing for patients for whom alternative treatment options are inadequate.
WARNING: RISK OF RESPIRATORY DEPRESSION AND CARDIAC ARREST WITH CONCOMITANT USE OF ALCOHOL OR OTHER CNS DEPRESSANTS; RISK OF SUBSTANCE ABUSE, DEPENDENCE, AND WITHDRAWAL; WITHDRAWAL SEIZURES; AND RISK OF SERIOUS SKIN REACTIONS.
Respiratory depression,Sedation and somnolence,Risk of abuse, misuse, and addiction,Dependence and withdrawal reactions,Suicidal thoughts or behavior
Risk of CNS depression and impaired motor function,Risk of abuse and dependence,Risk of withdrawal seizures upon abrupt discontinuation,Risk of serious skin reactions (e.g., Stevens-Johnson syndrome),Concomitant use with opioids may cause profound sedation, respiratory depression, coma, and death,Use in patients with compromised respiratory function or hepatic impairment requires caution
Hypersensitivity to clobazam or any component of the formulation,Severe hepatic impairment (Child-Pugh Class C)
Hypersensitivity to diazepam or any component of the formulation,Acute narrow-angle glaucoma,Concomitant use with opioid analgesics for acute treatment of seizure clusters (unless alternative treatments are not available)
Avoid grapefruit and grapefruit juice as they may increase levels of clobazam and its active metabolite. No other significant food interactions known.
No specific food interactions. Avoid alcohol consumption during VALTOCO use as it may increase CNS depressant effects.
Benzodiazepines are generally associated with increased risk of oral clefts when used in the first trimester. Use in the third trimester may cause neonatal sedation, withdrawal, or floppy infant syndrome. Specific fetal risk data for clobazam (Sympazan) are limited.
Diazepam (active moiety in VALTOCO) is Pregnancy Category D. First trimester: Associated with increased risk of congenital malformations, particularly cleft lip/palate, when used chronically. Second and third trimesters: May cause fetal benzodiazepine exposure leading to floppy infant syndrome, neonatal withdrawal, and central nervous system depression. Late third trimester or delivery: Risk of neonatal respiratory depression, hypotonia, and feeding difficulties.
Clobazam is excreted in breast milk. The milk-to-plasma ratio is approximately 0.3 to 0.5. Monitor infant for sedation, poor feeding, and weight gain. Avoid breastfeeding if possible.
Diazepam is excreted into breast milk with an M/P ratio approximately 0.3. The relative infant dose is low (2-5% of weight-adjusted maternal dose). Caution is advised due to potential accumulation in neonates (long half-life) causing sedation, poor feeding, and respiratory depression. Use only if clearly needed with infant monitoring.
Increased clearance of clobazam in pregnancy may require dose adjustments; monitor therapeutic response and adjust accordingly.
No specific dose adjustment recommended for VALTOCO during pregnancy for acute seizure management. However, due to increased volume of distribution and altered protein binding in pregnancy, a higher dose or more frequent dosing may be required for chronic use; clinical response should guide titration. Monitor for excessive sedation or respiratory depression as clearance may be reduced in late pregnancy.
Clobazam oral film (SYMPAZAN) is a benzodiazepine approved for adjunctive treatment of seizures associated with Lennox-Gastaut syndrome in patients aged 2 years and older. It is available as a rapidly dissolving film that can be placed on the tongue. The active metabolite N-desmethylclobazam is primarily renally excreted; adjust dose in renal impairment. Avoid abrupt discontinuation due to risk of withdrawal seizures. CYP2C19 poor metabolizers have significantly higher exposure to the active metabolite; consider dose reduction. Can cause sedation, dizziness, and somnolence; monitor for respiratory depression especially with other CNS depressants. Abuse potential exists; use with caution in patients with history of substance abuse.
VALTOCO (diazepam nasal spray) is indicated for acute treatment of intermittent, stereotypic episodes of frequent seizure activity (i.e., seizure clusters, acute repetitive seizures) in patients with epilepsy aged 6 years and older. Administer one spray into one nostril; if needed, a second spray into the opposite nostril can be given after 4 hours if seizure activity persists. Do not use more than two doses per episode. Onset of action is rapid (within 2-5 minutes). Monitor for respiratory depression, especially in patients with compromised respiratory function or concomitant CNS depressants. Each spray delivers 5 mg or 10 mg diazepam; the dose depends on patient weight (5 mg for <40 kg, 10 mg for ≥40 kg). Tilt patient's head back slightly during administration. Do not reuse the device; discard after use.
Place the film on your tongue where it will dissolve quickly; do not chew or swallow it whole.,Take this medication exactly as prescribed; do not increase the dose or stop suddenly without talking to your doctor to avoid withdrawal seizures.,Avoid driving or operating heavy machinery until you know how this drug affects you, as it may cause drowsiness, dizziness, or blurred vision.,Avoid alcohol and other sedating medications while taking SYMPAZAN, as they can increase the risk of severe drowsiness and breathing problems.,Tell your doctor if you have kidney or liver disease, or if you have a history of substance abuse or depression.,If you miss a dose, take it as soon as you remember; if it is close to the next dose, skip the missed dose and continue your regular schedule. Do not double the dose.,Store the film at room temperature away from moisture and heat; keep each film in its sealed pouch until ready to use.
Use VALTOCO exactly as prescribed; only for seizure clusters, not for daily seizures.,Administer one spray into one nostril; do not prime the device.,After administration, tilt head back slightly and breathe normally.,If seizure activity continues after 4 hours, a second dose may be given in the opposite nostril.,Do not use more than two doses per seizure episode; if ineffective, seek emergency medical help.,Store at room temperature (20-25°C); protect from light and moisture.,Keep out of reach of children; discard device after use.,May cause dizziness, drowsiness, or coordination problems; avoid driving or operating machinery until effects wear off.,Inform healthcare provider of all medications, especially CNS depressants (e.g., alcohol, opioids, sedatives).,Do not consume alcohol while using VALTOCO.
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 SYMPAZAN vs VALTOCO, answered by our medical review team.
SYMPAZAN is a Benzodiazepine Anticonvulsant that works by SYMPAZAN (clobazam) is a benzodiazepine that potentiates GABAergic inhibition via binding to the GABA-A receptor at the benzodiazepine site, enhancing chloride ion influx and neuronal hyperpolarization.. VALTOCO is a Benzodiazepine Anticonvulsant that works by GABA-A receptor positive allosteric modulator; increases chloride ion conductance, hyperpolarizes neurons, and suppresses seizure activity.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between SYMPAZAN and VALTOCO depend on the specific clinical indication. These are both Benzodiazepine Anticonvulsant agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of SYMPAZAN is: 10-20 mg orally three times daily (maximum 60 mg/day). If switching from another benzodiazepine, use equivalent dose.. The standard adult dose of VALTOCO is: 5 mg, 10 mg, 15 mg, or 20 mg intranasally as a single dose based on weight; for patients weighing <50 kg: 5 mg, 10 mg for 50-75 kg, 15 mg for 75-100 kg, 20 mg for >100 kg. In adults, maximum dose is 20 mg per seizure cluster.. 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 SYMPAZAN and VALTOCO 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. SYMPAZAN is classified as Category C. Benzodiazepines are generally associated with increased risk of oral clefts when used in the first trimester. Use in the third trimester may cause neonatal sedation, withdrawal, or. VALTOCO is classified as Category C. Diazepam (active moiety in VALTOCO) is Pregnancy Category D. First trimester: Associated with increased risk of congenital malformations, particularly cleft lip/palate, when used c. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.