What is Onfi: Uses, Warnings & Interactions

Updated May 14, 2025  •  Published Dec 30, 2020

Onfi overview

BRAND NAMES:

  • Sympazan, Onfi

Generic Names:

  • Clobazam

Uses:

  • Treats seizures from Lennox-Gastaut syndrome. This medicine is a benzodiazepine.

Therapeutic Classes:

  • Anticonvulsant, Sedative-Hypnotic

Forms:

  • Tablet, Thin Sheet, Liquid

How it’s taken:

  • By mouth

What is Onfi used for?

Onfi comes in the form of a liquid and is used to treat seizures caused by Lennox-Gastaut syndrome. Lennox-Gastaut syndrome is a severe form of childhood epilepsy that can also cause developmental and behavior problems. Onfi works by preventing excessively rapid and repetitive firing of electrical signals in the brain. Common Onfi side effects may include drowsiness, tired feeling, slurred speech and drooling.

What form(s) does Onfi come in

  • Tablet

  • Thin Sheet

  • Liquid

What are common Onfi doses?

  • Tablet 10MG

  • Tablet 20MG

  • Bottle 120ML of 2.5MG/ML

Common Onfi prescriptions

  • Onfi
    120ml of 2.5mg/ml bottle

  • Onfi
    10mg tablet

  • Onfi
    20mg tablet

How to take Onfi

  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Store the bottle upright and with the adapter in place. Throw away any unused oral liquid 90 days after you open the bottle.

  • Take your medicine as directed. Your dose may need to be changed several times to find what works best for you.

  • Film: Place the whole film on top of your tongue. Do not take any liquid when using this medicine. Do not chew, spit, or talk while the film dissolves. If you need a second film, wait until the first film dissolves before using a second film.

  • Oral liquid: Shake the bottle just before each dose. Use the bottle adapter and dosing syringe in the package to measure the right dose. Squirt the right amount of medicine directly into the corner of the mouth. Wash the syringe, barrel, and plunger after each use, and allow the parts to air dry. Do not put the syringe in the dishwasher.

  • Tablet: You may swallow the tablet whole, break it in half along the score, or crush and mix it in applesauce.

  • This medicine should come with a Medication Guide. Ask your pharmacist for a copy if you do not have one.

  • Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.

  • This medicine should come with a Medication Guide. Ask your pharmacist for a copy if you do not have one.

  • Take your medicine as directed. Your dose may need to be changed several times to find what works best for you.

  • Tablet: You may swallow the tablet whole, break it in half along the score, or crush and mix it in applesauce.

  • Oral liquid: Shake the bottle just before each dose. Use the bottle adapter and dosing syringe in the package to measure the right dose. Squirt the right amount of medicine directly into the corner of the mouth. Wash the syringe, barrel, and plunger after each use, and allow the parts to air dry. Do not put the syringe in the dishwasher.

  • Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.

  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Store the bottle upright and with the adapter in place. Throw away any unused oral liquid 90 days after you open the bottle.

  • Film: Place the whole film on top of your tongue. Do not take any liquid when using this medicine. Do not chew, spit, or talk while the film dissolves. If you need a second film, wait until the first film dissolves before using a second film.

What to do if you miss a dose of Onfi

Onfi contraindications

  • This medicine is not right for everyone. Do not use it if you had an allergic reaction to clobazam.

Onfi warnings

  • Do not stop using this medicine suddenly. Your doctor will need to slowly decrease your dose before you stop it completely.

  • Your doctor will check your progress and the effects of this medicine at regular visits. Keep all appointments.

  • This medicine may make you dizzy or drowsy. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.

  • This medicine can be habit-forming. Do not use more than your prescribed dose. Call your doctor if you think your medicine is not working.

  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

  • Tell your doctor if you are pregnant or breastfeeding, or if you have kidney disease, liver disease, lung disease or breathing problems, or a history of alcohol or drug abuse, depression, or a mood disorder.

  • This medicine may cause the following problems:Respiratory depression (serious breathing problem that can be life-threatening), when used with narcotic pain medicinesSerious skin reactions

  • This medicine can increase thoughts of suicide. Tell your doctor right away if you start to feel depressed and have thoughts about hurting yourself.

  • Birth control pills may not work as well when used with this medicine. Use a second form of birth control to keep from getting pregnant and for 28 days after your last dose.

Onfi interactions

  • Some medicines can affect how clobazam works. Tell your doctor if you are using any of the following:Fluconazole, fluvoxamine, omeprazole, ticlopidineBirth control pillsMedicine to treat depressionNarcotic pain medicine

  • Tell your doctor if you use anything else that makes you sleepy. Some examples are allergy medicine, narcotic pain medicine, and alcohol.

  • Do not drink alcohol while you are using this medicine.

  • This medicine may make you dizzy or drowsy. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.

  • Do not stop using this medicine suddenly. Your doctor will need to slowly decrease your dose before you stop it completely.

  • This medicine can be habit-forming. Do not use more than your prescribed dose. Call your doctor if you think your medicine is not working.

  • Your doctor will check your progress and the effects of this medicine at regular visits. Keep all appointments.

  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Onfi side effects

Serious Side Effects

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing

  • Blistering, peeling, red skin rash

  • Blue lips, fingernails, or skin

  • Confusion or unusual excitement, nervousness, irritability

  • Extreme drowsiness or weakness, slow heartbeat, trouble breathing

  • Depression, anxiety, irritability, hallucinations, trouble sleeping, unusual behavior, thoughts of hurting yourself or others

Less Serious Side Effects

  • Constipation

  • Clumsiness, trouble with coordination

  • Drooling

  • Dizziness, drowsiness, or sleepiness