Clobazam: uses, dosing, side effects & brands

Clobazam is a benzodiazepine sold in the U.S. under 3 brand and generic names, for seizures and lennox gastaut syndrome. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.

By the pharmaranks editorial teamReviewed against the FDA (openFDA label, NDC Directory & Enforcement) sourcesUpdated Jul 24, 2026How we research

Key facts

Drug class: Benzodiazepine
Treats (across its forms): Seizures and Lennox Gastaut Syndrome
Available as: Suspension · Tablet · Film
Sold as: 3 products — Clobazam, Onfi and Sympazan
Prescription?: Prescription only
Generic available?: Yes
What the pharmacy pays: about $8 for a 30-count supply — not your price
Boxed warning: Boxed warning

How Onfi is dosed

From the FDA label for Onfi (application NDA202067). Other clobazam products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.

For doses above 5 mg/day administer in two divided doses ( 2.1 ) Patients ≤30 kg body weight: Initiate at 5 mg daily and titrate as tolerated up to 20 mg daily ( 2.1 ) Patients >30 kg body weight: Initiate at 10 mg daily and titrate as tolerated up to 40 mg daily ( 2.1 ) Dosage adjustment needed in following groups: Geriatric patients ( 2.4 , 8.5 ) Known CYP2C19 poor metabolizers ( 2.5 ) Mild or moderate hepatic impairment; no information for severe hepatic impairment ( 2.7 , 8.8 ) Tablets: Administer whole, broken in half along the score, or crush and mix in applesauce ( 2.3 ) Measure prescribed amount of oral suspension using provided adapter and dosing syringe ( 2.3 ) Tablets and Oral suspension: Can be taken with or without food ( 2.3 ) 2.1 Dosing Information A daily dose of ONFI greater than 5 mg should be administered in divided doses twice daily; a 5 mg daily dose can be administered as a single dose. Dose patients according to body weight. Individualize dosing within each body weight group, based on clinical efficacy and tolerability. Each dose in Table 1 (e.g., 5 to 20 mg in ≤30 kg weight group) has been shown to be effective, although effectiveness increases with increasing dose [see Clinical Studies ( 14 )] . Do not proceed with dose escalation more rapidly than weekly, because serum concentrations of clobazam and its active metabolite require 5 and 9 days,…

Everything below is the FDA label for Onfi (suspension, tablet). Clobazam is also sold as film, and those are different medicines to take — follow the label for the one you were prescribed.

Onfi side effects

Clinically significant adverse reactions that appear in other sections of the labeling include the following: Risks from Concomitant Use with Opioids [see Warnings and Precautions ( 5.1 )] Abuse, Misuse, and Addiction [see Warnings and Precautions ( 5.2 )] Dependence and Withdrawal Reactions [see Warnings and Precautions ( 5.3 )] Potentiation of Sedation from Concomitant Use with Central Nervous System Depressants [see Warnings and Precautions ( 5.4 )] Somnolence or Sedation [see Warnings and Precautions ( 5.5 )] Serious Dermatological Reactions [see Contraindications ( 4 ), Warnings and Precautions ( 5.6 )] Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multiorgan Hypersensitivity [see Warnings and Precautions ( 5.7 )] Suicidal Behavior and Ideation [see Warnings and Precautions ( 5.8) ] Neonatal Sedation and Withdrawal Syndrome [see Warnings and Precautions ( 5.9) ] Adverse reactions that occurred at least 10% more frequently than placebo in any ONFI dose included constipation, somnolence or sedation, pyrexia, lethargy, and drooling ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Lundbeck at 1-800-455-1141 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to…

Who shouldn’t take Onfi

ONFI is contraindicated in patients with a history of hypersensitivity to the drug or its ingredients. Hypersensitivity reactions have included serious dermatological reactions [see Warnings and Precautions ( 5.6 , 5.7 )] . History of hypersensitivity to the drug or its ingredients ( 4 )

Onfi drug interactions

Alcohol: Increases blood levels of clobazam by about 50% ( 7.2 ) Drugs metabolized by CYP2D6: Lower doses of these drugs may be required when used concomitantly with ONFI ( 7.3 ) Strong or Moderate CYP2C19 Inhibitors: Dosage adjustment of ONFI may be necessary ( 7.4 ) 7.1 Opioids The concomitant use of benzodiazepines and opioids increases the risk of respiratory depression because of actions at different receptor sites in the CNS that control respiration. Benzodiazepines interact at GABA A sites, and opioids interact primarily at mu receptors. When benzodiazepines and opioids are combined, the potential for benzodiazepines to significantly worsen opioid-related respiratory depression exists. Limit dosage and duration of concomitant use of benzodiazepines and opioids, and follow patients closely for respiratory depression and sedation [see Warnings and Precautions ( 5.1 )] . 7.2 CNS Depressants and Alcohol Concomitant use of ONFI with other CNS depressants may increase the risk of sedation and somnolence [see Warnings and Precautions ( 5.4 )] . Alcohol, as a CNS depressant, will interact with ONFI in a similar way and also increases clobazam's maximum plasma exposure by approximately 50%. Therefore, caution patients or their caregivers against simultaneous use with other CNS depressant drugs or alcohol, and caution that the effects of other CNS depressant drugs or alcohol may be potentiated [see Warnings and Precautions ( 5.4 )] . 7.3 Effect of ONFI on Other Drugs Hormonal Contraceptives ONFI is a weak CYP3A4 inducer. As some hormonal contraceptives are metabolized by CYP3A4, their effectiveness may be diminished when given with ONFI. Additional non-hormonal forms of contraception are recommended when using ONFI [see Clinical Pharmacology ( 12.3 ), Patient Counseling Information ( 17 )] . Drugs Metabolized by CYP2D6 ONFI inhibits CYP2D6. Dose adjustment of drugs metabolized by CYP2D6 may be necessary [see Clinical Pharmacology ( 12.3 )] . 7.4 Effect of Other Drugs on ONFI Strong and moderate inhibitors of CYP2C19 Strong and moderate inhibitors of CYP2C19 may result in increased exposure to N-desmethylclobazam, the active metabolite of clobazam. This may increase the risk of dose-related adverse reactions. Dosage adjustment of ONFI may be necessary when co-administered with strong CYP2C19 inhibitors (e.g., fluconazole, fluvoxamine, ticlopidine) or moderate CYP2C19 inhibitors (e.g., omeprazole) [see Clinical Pharmacology ( 12.3 )] .

Every clobazam product we track (3)

Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.

Clobazam products
#	Drug	Rating	Type	Form	Generic?	Pharmacy pays
1	Clobazam	Not yet rated	Prescription	Suspension	Generic	$8	View →
2	Onfi Boxed warning	Not yet rated	Prescription	Suspension	Generic	$8	View →
3	Sympazan Boxed warning	Not yet rated	Prescription	Film	Generic	$8	View →

What clobazam pills look like

Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.

Clobazam pill imprints
Imprint	Strength	Colour	Shape	Maker
1;0	10 mg	white	oval	—
2;0	20 mg	white	oval	—
C;2	10 mg	white	oval	—
C;3	20 mg	white	oval	—
1;0	10 mg	white	oval	—
2;0	20 mg	white	oval	—
C5	5 mg	white	rectangle	—
C10	10 mg	white	rectangle	—
C20	20 mg	white	rectangle	—

Clobazam recalls

From the FDA Enforcement database. A recall covers specific lots — not the drug as a whole.

Can you crush or split clobazam?

At least one clobazamproduct is labelled to be swallowed whole — crushing an extended-release tablet releases the whole day’s dose at once. Which applies depends on the form you were given.

What each clobazam label says about crushing, splitting and chewing

How long clobazam keeps

The date on a sealed pack is not the only one: some clobazam labels start a second clock once the product is opened or mixed, as short as 90 days.

Does clobazam expire? The in-use limits and storage rules from its labels

Clobazam and breastfeeding

From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.

Limited information indicates that maternal doses of clobazam up to 30 mg daily produce low levels in milk. Short-term use would not be expected to cause any adverse effects in breastfed infants, especially if the infant is older than 2 months. During long-term administration, Monitor the infant for sedation, poor feeding and poor weight gain.

Full LactMed record for clobazam: levels in milk, effects in breastfed infants, and the drugs it would consider instead

National Institute of Child Health and Human Development, record revised October 15, 2024. LactMed states its information is not a substitute for professional judgement.

What people report to the FDA about clobazam

The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 17,599 reports naming clobazam, and the FDA flagged 87% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:

seizure2,935 reports
somnolence1,357 reports
epilepsy839 reports
fatigue742 reports
status epilepticus633 reports
multiple-drug resistance571 reports
generalised tonic-clonic seizure516 reports
foetal exposure during pregnancy508 reports

Read these as a signal, not a rate. A report does not mean clobazam caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.

Source: openFDA drug/event (FAERS), retrieved August 25, 2026.

Related calculators

How long it stays in your system →

Frequently asked questions

What is Onfi?

Onfi (Clobazam) is a benzodiazepine used to treat Seizures, Lennox Gastaut Syndrome.

What kind of drug is clobazam?

The FDA classifies clobazam as a benzodiazepine. Benzodiazepines boost the brain's main calming chemical, GABA, by binding to the GABA-A receptor and making its chloride channel open more often. This quiets nerve activity, producing sedation, reduced anxiety, muscle relaxation, and protection against seizures. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.

Can you take clobazam with other medicines?

It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run clobazam against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.

What brand names is clobazam sold under?

We track 3 clobazam-containing products in the U.S.: Clobazam, Onfi and Sympazan. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.

What forms does clobazam come in?

Across the brands we track, clobazam is currently marketed as suspension, tablet and film, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.

Is there a generic clobazam?

Yes. Our catalog lists 1 generic clobazam product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.

Has clobazam been recalled?

The FDA's Enforcement database lists 3 recall records whose product description mentions clobazam. The most recent: Clobazam Tablets (Jan 7, 2025). A recall applies to specific lots, not to the drug as a whole — check the record for the affected lot numbers.

Cite this page

APA: pharmaranks. (2026, July 24). Clobazam: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/clobazam
MLA: “Clobazam: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/clobazam.

We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.

Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.

Read the full FDA label for clobazam on DailyMed (NIH) ↗ — including its boxed warning in full.