Onfi treats certain types of seizures. Do not drink alcohol or take other medicines that may make you sleepy or dizzy while taking Onfi as it may cause you to be more sleepy or dizzy.

Onfi Overview


Onfi is a prescription medication used to treat seizures associated with Lennox-Gastaut syndrome. Onfi belongs to a group of drugs called benzodiazepines. It works by decreasing the abnormal electrical activity in the brain.

This medication comes in tablet and oral (by mouth) suspension form. It is taken once or twice a day, with or without food.

Common side effects of Onfi include sleepiness, drooling, and constipation.

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  • Other

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  • Less than a week
  • A couple weeks
  • A month or so
  • A few months
  • A year or so
  • Two years or more

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Onfi Cautionary Labels


Uses of Onfi

Onfi is a prescription medicine used along with other medicines to treat seizures associated with Lennox-Gastaut syndrome in people 2 years of age or older. Lennox-Gasaut is a type of epilepsy that starts in childhood and causes several types of seizures, developmental delays, and behavioral changes.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.


Side Effects of Onfi

Serious side effects have been reported. See "Drug Precautions" section.

The most common side effects of Onfi include:

  • sleepiness 
  • drooling 
  • constipation 
  • cough 
  • pain with urination 
  • fever 
  • acting aggressive, being angry, or violent 
  • difficulty sleeping 
  • slurred speech 
  • tiredness 
  • problems with breathing

These are not all the possible side effects of Onfi. For more information, ask your doctor or pharmacist.

Onfi Interactions

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

  • birth control medicines (pills, patches, rings, implants, injections, and IUDs)
  • fluconazole (Diflucan)
  • antianxiety medicines
  • pain medicines
  • other seizure medicines

This is not a complete list of possible interactions. Talk to your doctor or pharmacist for more information.

Onfi Precautions

Serious skin reactions have been seen with Onfi and may require stopping its use. Do not stop taking Onfi without first talking to your healthcare provider.
A serious skin reaction can happen at any time during your treatment with Onfi, but is more likely to happen within the first 8 weeks of treatment. These skin reactions need to be treated right away. Call your healthcare provider immediately if you have skin blisters, peeling rash, sores in the mouth, hives or any other allergic reaction.
This medication can cause withdrawal symptoms, abuse, and dependence. Onfi  is a federally controlled substance (C-IV). Talk to your healthcare provider before stopping this medication and to discuss abuse and dependence.
Like other antiepileptic drugs, Onfi may cause suicidal thoughts or actions in a very small number of people, about 1 in 500. Call your healthcare provider right away if you have any of these symptoms, especially if they are new, worse, or worry you: 
  • thoughts about suicide or dying
  • attempts to commit suicide
  • new or worse depression
  • new or worse anxiety
  • feeling agitated or restless
  • panic attacks
  • trouble sleeping (insomnia)
  • new or worse irritability
  • acting aggressive, being angry, or violent
  • acting on dangerous impulses
  • an extreme increase in activity and talking (mania)
  • other unusual changes in behavior or mood

This medication may cause dizziness and drowsiness:

  • Do not drive, operate heavy machinery, or do other dangerous activities until you know how Onfi affects you. 
  • Do not drink alcohol or take other medicines that may make you sleepy or dizzy while taking Onfi until you talk to your healthcare provider. When taken with alcohol or medicines that cause sleepiness or dizziness, Onfi may make your sleepiness or dizziness much worse.

Onfi Food Interactions

Medicines can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of Onfi there are no specific foods that you must exclude from your diet when receiving Onfi.

Inform MD

Before you take Onfi, tell your doctor if you:

  • have liver or kidney problems 
  • have lung problems (respiratory disease) 
  • have or have had depression, mood problems, or suicidal thoughts or behavior 
  • have any other medical conditions
  • take other medicines 
  • use birth control medicine. Onfi may cause your birth control medicine to be less effective. Talk to your doctor about the best birth control method to use. 
  • are pregnant or plan to become pregnant. Onfi may harm your unborn baby. 

Onfi and Pregnancy

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

This medication falls into category C. In animal studies, pregnant animals were given this medication and had some babies born with problems. No well-controlled studies have been done in humans. Therefore, this medication may be used if the potential benefits to the mother outweigh the potential risks to the unborn child.

Onfi and Lactation

Tell your doctor if you are breastfeeding or plan to breastfeed. Onfi is excreted in human breast milk. It is unknown if Onfi will harm your nursing baby.

Onfi Usage

  • Onfi can be taken whole, or crushed and mixed in applesauce. 
  • Take Onfi exactly as your doctor tells you to take it. 
  • Your doctor will tell you how much Onfi to take and when to take it. Your doctor may change your dose if needed. Do not change your dose of Onfi without talking to your doctor. 
  • Do not stop taking Onfi without first talking to your doctor. 
  • Stopping Onfi suddenly can cause serious problems. If you take too much Onfi, call your doctor or go to the nearest hospital emergency room right away.

Onfi Dosage

Take Onfi exactly as prescribed by your doctor. Follow the directions on your prescription label carefully. Your doctor will determine the best dose for you. Dosing is individualized based on weight, response to the medicine, and how it is tolerated.

The recommended daily dosing ranges are:

Starting dose: 5 mg to 10 mg

Starting day 7: 10 mg to 20 mg

Starting day 14: 20 mg to 40 mg


Onfi Overdose

If you take too much Onfi call your local Poison Control Center or seek emergency medical attention right away.

Other Requirements

  • Store Onfi between 68°F to 77°F (20°C to 25°C).
  • Keep Onfi and all medicines out of the reach of children.