Onfi is a brand-name prescription medication. It’s approved to treat seizures in people who have a rare type of epilepsy called Lennox-Gastaut syndrome (LGS). For this purpose, Onfi is used as an adjunctive treatment, which means you’ll take the drug with other epilepsy medications.

Onfi is approved for use in adults as well as children ages 2 years and older.

Onfi forms and strengths

Onfi comes in two forms. One is a tablet that you swallow. The tablet is available in these strengths: 10 milligrams (mg) and 20 mg.

The other form of Onfi is an oral suspension (a type of mixture in liquid). You use an oral syringe to swallow the medication. The suspension is available in one strength: 2.5 mg per milliliter (mg/mL).

Onfi drug class

Onfi contains the active drug clobazam, which belongs to a class of medications called benzodiazepines. (A class of medications is a group of drugs that work in a similar way.)

These medications have a high risk of misuse and addiction. And if you use too much of them, they can also cause dangerous side effects including coma and, in some cases, death. The use of benzodiazepines with other drugs, including alcohol, can also cause these dangerous side effects.

Is Onfi a controlled substance?

Yes, Onfi is a controlled substance, which is a medication whose use is specially regulated under federal law.

The Drug Enforcement Administration (DEA) places medications into “schedules” based on several factors. These factors include the medical uses for the drug, the drug’s known safety risks, and the drug’s potential for misuse. The schedules range from Schedule II (the most severe) to Schedule V (the least severe). Drugs that don’t appear to have potential for misuse won’t have a schedule at all.

Onfi is a Schedule IV medication. This means that although Onfi has a risk of misuse and causing you to become dependent on it, the risk is lower compared with other controlled substances.

Effectiveness

Clinical trials have shown Onfi to be effective for treating seizures in people with LGS.

In one study, people with LGS were randomly assigned to take either Onfi or a placebo (treatment with no active drug). The researchers wanted to see if Onfi was better at reducing the number of seizures people had each week. After 12 weeks, the results showed the following:

  • In people who took Onfi, the number of seizures they had each week dropped by 41.2% to 68.3%, depending on which dose they used.
  • In people who took a placebo, the number of seizures they had each week dropped by 12.1%.

Onfi is available as a generic drug called clobazam. A generic drug is an exact copy of the active drug in a brand-name medication. The generic is considered to be as safe and effective as the original drug. Generics tend to cost less than brand-name drugs.

In some cases, the brand-name drug and the generic version may come in different forms and strengths.

Onfi contains the active drug clobazam. (As the active drug, clobazam is the ingredient that makes Onfi work.)

Onfi can cause mild or serious side effects. The following lists contain some of the key side effects that may occur while taking Onfi. These lists don’t include all possible side effects.

For more information on the possible side effects of Onfi, talk with your doctor or pharmacist. They can give you tips on how to deal with any side effects that may be bothersome.

Note: The Food and Drug Administration (FDA) tracks side effects of drugs it has approved. If you would like to report to the FDA a side effect you’ve had with Onfi, you can do so through MedWatch.

Mild side effects

Mild side effects of Onfi can include:*

Most of these side effects may go away within a few days or a couple of weeks. But if they become more severe or don’t go away, talk with your doctor or pharmacist.

* This is a partial list of mild side effects from Onfi. To learn about other mild side effects, talk with your doctor or pharmacist, or visit Onfi’s Medication Guide.

Serious side effects

Serious side effects from Onfi aren’t common, but they can occur. Call your doctor right away if you have serious side effects. Call 911 if your symptoms feel life threatening or if you think you’re having a medical emergency.

Serious side effects can include:

For more information on these serious side effects, including possible symptoms, please see the “Side effect details” section below.

Side effects in children and toddlers

Onfi is approved for use in children ages 2 years and older. Side effects in children aren’t expected to be any different from those in adults.

Side effect details

You may wonder how often certain side effects occur with this drug, or whether certain side effects pertain to it. Here’s some detail on some of the side effects this drug may or may not cause.

Allergic reaction

As with most drugs, some people can have an allergic reaction after taking Onfi. It’s unknown how many people have had this side effect with the medication.

Symptoms of a mild allergic reaction can include:

  • skin rash
  • itchiness
  • flushing (warmth and redness in your skin)

A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include:

  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your tongue, mouth, or throat
  • trouble breathing

Call your doctor right away if you have a severe allergic reaction to Onfi. Call 911 if your symptoms feel life threatening or if you think you’re having a medical emergency.

Severe drowsiness

It’s common to experience drowsiness while taking Onfi. Here’s what researchers found in clinical trials:

  • 17% to 32% of people who took Onfi reported feeling drowsy or sedated, depending on the dose they took.
  • In comparison, 15% of people who took a placebo (treatment with no active drug) reported drowsiness.

In most people, the drowsy or sedated feeling began the first month they started using Onfi. For some people, the feeling went away after they kept taking Onfi.

Central nervous system depressant

Onfi can cause drowsiness because it’s a type of drug called a central nervous system (CNS) depressant. Your CNS is made up of your brain and your spinal cord. Your spinal cord contains nerves that your brain uses to send signals to the rest of your body.

CNS depressants are a type of medication called a sedative, which slows down your CNS and can cause side effects like drowsiness.

Drowsiness related to dose

In some people, Onfi can cause severe drowsiness. The severity of drowsiness is related to the dose. So if you take a higher dose of Onfi, you may be at a greater risk for severe drowsiness. If you use other medications that cause drowsiness, that can also place you at a higher risk for experiencing severe drowsiness.

Because of the possible drowsiness, you’ll want to avoid any activity that requires you to be mentally alert until you know how Onfi will affect you. This includes driving a car or operating heavy machinery.

If you have any concerns about feeling drowsy while using Onfi, talk with your doctor.

Fever

Fever was one of the more common side effects reported by people who used Onfi in clinical trials. Researchers found the following:

  • Depending on the dose of Onfi people took, 12% to 17% of them reported having a fever.
  • Only 3% of people who took a placebo had this side effect.

Fever can also be a symptom of upper respiratory infections (URIs), such as the common cold. A URI is another potential side effect of Onfi.

If you develop a fever while taking Onfi, tell your doctor. They can help determine whether it’s due to an infection or if it’s a side effect of the drug.

Serious skin reaction

Although rare, Onfi has caused serious skin reactions in both adults and children. These reactions include Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). The reactions weren’t reported in clinical trials, but they occurred since the drug was released onto the market.

Symptoms of SJS or TEN can include:

  • skin blisters
  • skin rash
  • hives (itchy welts on your skin)
  • sores in your mouth

Be sure to check for the above symptoms while taking Onfi, especially during the first 8 weeks of use. If you think you’re having a serious skin reaction, call your doctor right away. In some cases, SJS and TEN can be life threatening.

Weight gain

Weight gain isn’t a direct side effect of Onfi. However, the drug can cause increased appetite in some people, which could lead to weight gain. In clinical trials, 2% to 5% of people who took Onfi reported an increase in appetite, depending on the dose. No one who took a placebo reported this side effect.

If you’re concerned about an increase in your appetite while using Onfi, talk with your doctor. They can help review your diet and exercise habits.

Depression and suicidal thoughts or behaviors

Like other medications used for treating epilepsy, Onfi can cause depression and suicidal thoughts or behaviors.

Clinical studies showed that suicidal thoughts or behaviors were observed:

  • two times more often in people who took epilepsy medications like Onfi (0.43% of people who took epilepsy drugs compared with 0.24% of people who took a placebo)
  • in about 1 of every 530 people who took epilepsy medications like Onfi

These rare but serious symptoms were seen as soon as 1 week after people started using the medication and continued throughout the treatment.

When starting Onfi treatment, pay close attention to your feelings, thoughts, moods, and behaviors. You’ll want to be on the lookout for any changes, especially sudden ones, in your thoughts, moods, and actions. These could be side effects due to Onfi.

Symptoms of depression and suicidal thoughts or behaviors

Symptoms of depression and suicidal thoughts or behaviors can include:

  • new or worsened anxiety, depression, or irritability (feeling irritable)
  • having thoughts about dying or suicide
  • panic attacks
  • insomnia (trouble sleeping)
  • other unusual changes in your typical mood or behaviors
  • an urge to act on dangerous impulses

If you have any of these symptoms, call your doctor right away. They’ll be able to work with you to determine if these are a result of Onfi or if something else could be causing your symptoms. They can also see whether a different medication may work better for you.

The Onfi dosage your doctor prescribes will depend on several factors. These include:

  • how well you respond to Onfi
  • your weight and age
  • other medical conditions you may have

With Onfi, your doctor will start you on a low dosage. Then they’ll adjust it over time to reach the amount that’s right for you. Your doctor will ultimately prescribe the smallest dosage that provides the desired effect.

The following information describes dosages that are commonly used or recommended. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs.

Drug forms and strengths

Onfi comes in two forms. One is a tablet that you swallow. The tablet is available in two strengths: 10 milligrams (mg) and 20 mg.

The other form of Onfi is a suspension (a type of mixture in liquid). You use an oral syringe to swallow the medication. The suspension is available in one strength: 2.5 mg per milliliter mg/mL.

Dosage for seizures

The Onfi dosage for seizures depends on your body weight.

If you weigh more than 66 pounds (30 kilograms), you’ll start by taking 10 mg of Onfi a day. The dose is divided into two: 5 mg in the morning and 5 mg in the evening.

If 10 mg doesn’t work for you, your doctor may increase your dosage to 20 mg a day. You’ll take this as two separate doses: 10 mg in the morning and 10 mg in the evening. Your doctor won’t likely make this increase in dosage any sooner than 7 days after you started using Onfi.

If the 20-mg dosage isn’t working for you, your doctor can again increase your total daily dose to 40 mg. You’ll take this as two separate doses: 20 mg in the morning and 20 mg in the evening. Your doctor likely won’t make this increase in dosage any sooner than 14 days after you started using Onfi.

Your doctor may give you a different dosage depending on several factors, including your age and whether you have liver disease. If you have questions about the dosage that’s right for you, talk with your doctor.

Pediatric dosage

Onfi is approved for use in children ages 2 years and older.

Children weighing less than 66 lb (30 kg)

For children weighing less than 66 lb (30 kg), the starting dosage of Onfi is 5 mg, once a day.

If the 5-mg dose isn’t effective, your child’s doctor can increase the dosage to a total of 10 mg a day. Your child will take this as two separate doses: 5 mg in the morning and 5 mg in the evening.

If the 10-mg dose still isn’t effective, your child’s doctor can increase the Onfi dosage again to a total of 20 mg a day. Your child will take this as two separate doses: 10 mg in the morning and 10 mg in the evening.

Children weighing more than 66 lb (30 kg)

For dosage information for children who weigh more than 66 lb (30 kg), see the “Dosage for seizures” section above.

What if I miss a dose?

To help make sure that you don’t miss a dose, try setting a reminder on your phone. A medication timer may be useful, too.

Will I need to use this drug long term?

Onfi is meant to be used as a long-term treatment. If you and your doctor determine that Onfi is safe and effective for you, you’ll likely take it long term.

The Food and Drug Administration (FDA) approves prescription drugs such as Onfi to treat certain conditions. Onfi may also be used off-label for other conditions. Off-label use is when a drug that’s approved to treat one condition is used to treat a different condition.

Onfi for seizures

Onfi is approved by the FDA to treat seizures in people who have a type of epilepsy called Lennox-Gastaut syndrome (LGS). For treating LGS, Onfi is used as adjunctive therapy. This means you’ll take Onfi in addition to your other epilepsy medications.

Onfi is approved for use in adults as well as children ages 2 years and older.

Seizures and LGS explained

Seizures are changes in the electrical activity of your brain. Mild seizures may have no symptoms, while severe seizures can include symptoms such as intense shaking. There are several kinds of seizures.

LGS is a rare and severe kind of epilepsy (a condition in which you have seizures repeatedly). LGS often begins in childhood, usually between ages 2 and 6 years. People with LGS can have any type of seizure. The most common include tonic seizures, atonic drop seizures, and generalized tonic-clonic seizures.

In addition to having seizures, people with LGS may also have trouble learning and developmental delays, which can be moderate or severe. Although these learning and developmental problems occur in most people with LGS, they aren’t required for a diagnosis. And they may not be present or noticeable during the beginning stages of LGS.

With LGS, cognitive function gets worse with time. Cognitive function includes mental actions such as thinking, memory, and attention.

Effectiveness for seizures

Onfi has been shown to be effective for treating seizures due to LGS.

In one study, people with LGS were randomly assigned to take either Onfi or a placebo (treatment with no active medication). The researchers wanted to see if Onfi was better at reducing the number of seizures people in the study had each week.

To do this, researchers first observed the people in the study for 4 weeks. This allowed them to establish a baseline number of seizures the people had before they used either Onfi or a placebo. Then people took either Onfi or a placebo for 12 weeks.

The researchers tracked the number of seizures the people had each week during the clinical trial, and then compared this to the baseline numbers. After 12 weeks, the results showed the following:

  • In people who took Onfi, the number of seizures they had each week dropped by 41.2% to 68.3%, depending on which dose they used.
  • In people who took a placebo, the number of seizures they had each week dropped by 12.1%.

People kept taking other epilepsy drugs during the study. The epilepsy medications most commonly used included lamotrigine (Lamictal), levetiracetam (Keppra), topiramate (Topamax), and divalproex sodium (Depakote, others).

Off-label uses for Onfi

In addition to the uses listed above, Onfi may be used off-label for other purposes. Off-label drug use is when a drug that’s approved for one or more use(s) is prescribed for a different one that’s not approved. Below are examples of off-label uses for Onfi.

Onfi for other types of seizures

Onfi is currently FDA-approved to treat only seizures due to LGS. However, the drug may be used off-label to treat other types of epilepsy. In countries besides the United States, Onfi is approved for treating different types of seizures than those caused by LGS.

For example, Onfi may be used in adults with drug-refractory epilepsy (DRE). This condition occurs when medications don’t bring your seizures under control.

One study looked at adults with DRE who were prescribed Onfi. Half of the people in the study had a 50% or more drop in the number of seizures they had.

If you have questions about using Onfi for other types of seizures, talk with your doctor.

Onfi for anxiety

The FDA hasn’t approved Onfi to treat anxiety. But the medication is approved for treating acute and chronic anxiety in other countries. (“Acute” means sudden, and “chronic” refers to long term.)

Onfi belongs to a class of medications known as benzodiazepines. (A class of medications is a group of drugs that work in a similar way.) Other medications in this class can be used to treat anxiety, so it’s thought that Onfi could possibly work to treat anxiety, too.

One study compared Onfi with another benzodiazepine drug called lorazepam (Ativan) and with the anxiety medication buspirone (Buspar). The researchers found all three drugs to be similarly effective in treating anxiety.

If you have questions about using Onfi for anxiety, talk with your doctor.

Onfi and children

Onfi is approved for use in adults as well as children ages 2 years and older.

Onfi is approved to treat seizures in people who have a rare type of epilepsy called Lennox-Gastaut syndrome (LGS). For this purpose, Onfi is used as an adjunctive treatment, which means you’ll take the drug with other epilepsy medications. (Onfi isn’t approved to be used as the only seizure medication in people with LGS.)

Examples of other epilepsy medications that you may take with Onfi include:

  • divalproex sodium (Depakote)
  • lamotrigine (Lamictal)
  • levetiracetam (Keppra)
  • topiramate (Topamax)

You shouldn’t drink alcohol while taking Onfi.

Alcohol and Onfi are both substances known as central nervous system (CNS) depressants. Your CNS is made up of your brain and your spinal cord. Your spinal cord contains nerves that your brain uses to send signals to the rest of your body. CNS depressants slow down your CNS, and this can cause side effects like drowsiness and excessive sleepiness.

Combining two CNS depressants, such as alcohol and Onfi, can further increase your risk for side effects, including serious ones. (See the “Onfi side effects” section above to learn more.)

In addition to being a CNS depressant, alcohol can also increase the level of Onfi in your body.

If you drink alcohol and are thinking about using Onfi, talk with your doctor.

Onfi can interact with several other medications.

Different interactions can cause different effects. For instance, some interactions can interfere with how well a drug works. Other interactions can increase the number of side effects or make them more severe.

FDA warning: Onfi use with opioids

The Food and Drug Administration (FDA) has issued a boxed warning for Onfi regarding using the drug with opioid medications. A boxed warning is the most severe warning from the FDA.

The use of Onfi with opioids can cause severe side effects. These effects can include sedation (extreme drowsiness or tiredness) and respiratory depression (slow and weak breathing). They can also include coma and, in some cases, death.

Your doctor will prescribe Onfi with an opioid only when no other treatments will work for you. And if you do use Onfi with an opioid, you should take the lowest dose of Onfi that’s effective for you. Your doctor will monitor you for symptoms of sedation and respiratory depression during your Onfi treatment.

Onfi and other medications

Below are some other medications that can interact with Onfi. This section doesn’t contain all drugs that may interact with Onfi.

Before taking Onfi, talk with your doctor and pharmacist. Tell them about all prescription, over-the-counter, and other drugs you take. Also tell them about any vitamins, herbs, and supplements you use. Sharing this information can help you avoid potential interactions.

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

Onfi and other drugs that can affect your central nervous system

Onfi is a type of drug called a central nervous system (CNS) depressant. Your CNS is made up of your brain and your spinal cord. Your spinal cord contains nerves that your brain uses to send signals to the rest of your body. CNS depressants slow down your CNS, and this can cause side effects like drowsiness and excessive sleepiness.

Combining two CNS depressants can further increase your risk for side effects, including serious ones. (See the “Onfi side effects” section above to learn more.)

Examples of other CNS depressants include:

  • opioids (see the “FDA warning: Onfi use with opioids” section above)
  • other benzodiazepines, such as alprazolam (Xanax) and zolpidem (Ambien)
  • diphenhydramine (Benadryl)
  • muscle relaxers, such as baclofen (Lioresal) and cyclobenzaprine
  • medications used for certain mood disorders, such as haloperidol (Haldol)
  • medications used for insomnia (trouble sleeping), such as eszopiclone (Lunesta)

It’s not recommended that you use Onfi with another CNS depressant. But if no other treatments will work for your condition, you may have to take both medications. If this is the case, your doctor will monitor you very closely for any side effects. And they’ll try to keep the doses of your medications as low as possible.

Onfi and certain drugs that affect how your body breaks down Onfi

Taking Onfi with certain medications that affect how your body metabolizes (breaks down) Onfi can change the level of Onfi in your system. This can increase your risk for side effects. See the “Onfi side effects” section above to learn more.

Examples of medications that can affect your body’s level of Onfi include:

Tell your doctor about all the medications you take. They can determine if any will affect how your body breaks down Onfi. If you need to take one of these drugs during your Onfi treatment, your doctor will monitor you closely for side effects. They may also change your dose of Onfi or switch you to a different medication for seizures.

Onfi and hormonal birth control

If you use hormonal contraception (birth control that contains hormones), keep in mind that Onfi may make it less effective. This is because Onfi can speed up how quickly your body processes hormonal contraception. With a lower level of hormonal contraception in your body, you have an increased risk for becoming pregnant.

Examples of hormonal contraceptives include:

  • birth control pills, such as:
    • ethinyl estradiol/drospirenone/levomefolate (Beyaz)
    • ethinyl estradiol/norethindrone acetate (Loestrin)
    • ethinyl estradiol/drospirenone (Yasmin, Yaz)
  • birth control shot:
    • medroxyprogesterone acetate (Depo-Provera)
  • birth control ring:
    • etonogestrel/ethinyl estradiol (NuvaRing)
  • birth control patch:
    • ethinyl estradiol/norelgestromin

Nonhormonal forms of birth control

If you are using a hormonal contraceptive, your doctor may recommend that you switch to a nonhormonal form of birth control while taking Onfi.

Examples of nonhormonal forms of birth control include:

If you have additional questions about birth control while using Onfi, see the “Onfi and birth control” section below and talk with your doctor.

Other IUDs

Certain IUDs contain levonorgestrel, making them a type of hormonal contraception. These include Kyleena, Liletta, Mirena, and Skyla.

However, a small study showed that the use of Mirena with epilepsy drugs didn’t affect how well Mirena worked.

If you’re using one of these IUD products, talk with your doctor about your specific birth control needs before taking Onfi.

Onfi and herbs and supplements

There aren’t any herbs or supplements that have been specifically reported to interact with Onfi. However, you should still check with your doctor or pharmacist before using any of these products while taking Onfi.

Onfi and foods

There aren’t any foods that have been specifically reported to interact with Onfi. If you have any questions about eating certain foods with Onfi, talk with your doctor.

As with all medications, the cost of Onfi can vary. To find current prices for Onfi tablets (or other forms) in your area, check out GoodRx.com.

The cost you find on GoodRx.com is what you may pay without insurance. The actual price you’ll pay depends on your insurance plan, your location, and the pharmacy you use.

Your insurance plan may require you to get prior authorization before approving coverage for Onfi. This means that your doctor and insurance company will need to communicate about your prescription before the insurance company will cover the drug. The insurance company will review the prior authorization request and decide if the drug will be covered.

If you’re not sure if you’ll need to get prior authorization for Onfi, contact your insurance company.

Financial and insurance assistance

If you need financial support to pay for Onfi, or if you need help understanding your insurance coverage, help is available.

Lundbeck, the manufacturer of Onfi, offers the ONFI Savings and Support program for people with commercial insurance. Through this program, you may qualify for a 14-day free trial as well as a copay savings card.

For more information and to find out if you’re eligible for support, call 855-345-6634 or visit the program website.

Generic version

Onfi is available in a generic form called clobazam. A generic drug is an exact copy of the active drug in a brand-name medication.

The generic is considered to be as safe and effective as the original drug. And generics tend to cost less than brand-name drugs. To find out how the cost of clobazam compares to the cost of Onfi, visit GoodRx.com.

If your doctor has prescribed Onfi and you’re interested in using clobazam instead, talk with your doctor. They may have a preference for one version or the other. You’ll also need to check your insurance plan, as it may only cover one or the other.

Other drugs are available that can treat your condition. Some may be a better fit for you than others. If you’re interested in finding an alternative to Onfi, talk with your doctor. They can tell you about other medications that may work well for you.

Note: Some of the drugs listed here are used off-label to treat this specific condition. Off-label use is when a drug that’s approved to treat one condition is used to treat a different condition.

Alternatives for seizures

Examples of other drugs that may be used to treat seizures due to Lennox-Gastaut syndrome (LGS) and are approved for this use include:

Other drugs that may be used to treat seizures due to LGS, but are used off-label for this condition, include:

  • carbamazepine (Tegretol, others)
  • clonazepam (Klonopin)
  • diazepam (Valium)
  • divalproex sodium (Depakote)
  • ethosuximide (Zarontin)
  • gabapentin (Neurontin)
  • lacosamide (Vimpat)
  • levetiracetam (Keppra)
  • lorazepam (Ativan)
  • oxcarbazepine (Trileptal, Oxtellar)
  • perampanel (Fycompa)
  • phenobarbital
  • phenytoin (Dilantin)
  • pregabalin (Lyrica)
  • primidone (Mysoline)
  • tiagabine (Gabitril)
  • valproic acid
  • vigabatrin (Sabril)
  • zonisamide (Zonegran)

You may wonder how Onfi compares with other medications that are prescribed for similar uses. Here we look at how Onfi and Sympazan are alike and different.

Ingredients

Both Onfi and Sympazan contain the active drug clobazam. But the medications come in different forms.

Uses

The Food and Drug Administration (FDA) has approved both Onfi* and Sympazan* to treat seizures in people with a type of epilepsy called Lennox-Gastaut syndrome (LGS). For this purpose, both Onfi and Sympazan are used as an adjunctive treatment. This means you’ll take either Onfi or Sympazan with other epilepsy medications.

Both Onfi and Sympazan are approved for use in adults as well as children ages 2 years and older.

* Both Onfi and Sympazan have a boxed warning for risks when used with opioids. A boxed warning is the most serious warning from the FDA. For more information, see “FDA warning: Onfi use with opioids” at the beginning of this article.

Drug forms and administration

Onfi comes in two forms. One is a tablet that you swallow. The other form of Onfi is a suspension (a type of mixture in liquid). You use an oral syringe to swallow the medication in this form.

Sympazan comes as an oral film that you apply to the top of your tongue, where it dissolves and releases the medication.

Side effects and risks

Onfi and Sympazan both contain clobazam. Therefore, these medications can cause very similar side effects, but some different ones as well. Below are examples of these side effects.

Mild side effects

This list contains up to 10 of the most common mild side effects that can occur with Onfi and Sympazan (when taken individually):

  • constipation
  • feeling unusually sleepy or drowsy
  • feeling more tired or having less energy than usual
  • trouble sleeping
  • acting aggressively or violently, or feeling more angry than usual
  • fever
  • drooling
  • ataxia (trouble controlling or coordinating your muscles)
  • upper respiratory infection
  • vomiting

Serious side effects

This list contains examples of serious side effects that can occur with Onfi and Sympazan (when taken individually).

Effectiveness

The only condition both Onfi and Sympazan are FDA-approved to treat is seizures due to LGS, when used with other medications for seizures.

These drugs haven’t been directly compared in clinical studies, but studies have found both Onfi and Sympazan to be effective for treating seizures due to LGS, when used with other medications for seizures.

Costs

According to estimates on GoodRx.com, costs of Onfi and Sympazan will vary depending on your treatment plan. The actual price you’ll pay for either drug depends on your insurance plan, your location, and the pharmacy you use.

Onfi and Sympazanare both brand-name drugs. Onfi is also available as a generic drug called clobazam. This is the active drug ingredient in Onfi. There are currently no generic forms for Sympazan. Brand-name medications usually cost more than generics.

Like Sympazan(above), the drug Banzelhas uses similar to those of Onfi. Here’s a comparison of how Onfi and Banzelare alike and different.

Ingredients

Onfi contains the active drug clobazam, which belongs to a class of medications called benzodiazepines. (A class of medications is a group of drugs that work in a similar way.)

Banzel contains the active drug rufinamide. The class of medications that rufinamide belongs to is called the anticonvulsant class.

Uses

The Food and Drug Administration (FDA) has approved both Onfi* and Banzel to treat seizures in people with a type of epilepsy called Lennox-Gastaut syndrome (LGS). For this purpose, both Onfi and Banzel are used as an adjunctive treatment. This means you’ll take either Onfi or Banzel with other epilepsy medications.

The two drugs do differ in who they’re used for. Onfi is approved for use in adults as well as children ages 2 years and older. Banzel is approved for use in adults as well as children ages 1 year and older.

* Onfi has a boxed warning for risks when used with opioids. A boxed warning is the most serious warning from the FDA. For more information, see “FDA warning: Onfi use with opioids” at the beginning of this article.

Drug forms and administration

Both Onfi and Banzel come in two forms. One is a tablet that you swallow. The other form is a suspension (a type of mixture in liquid). You use an oral syringe to swallow the medication in this form.

Side effects and risks

Onfi and Banzel contain different drugs, even though they’re used to treat the same condition. Therefore, these medications can cause very similar side effects, but some different ones as well. Below are examples of these side effects.

Mild side effects

These lists contain up to 10 of the most common mild side effects that can occur with Onfi, with Banzel, or with both drugs (when taken individually).

  • Can occur with Onfi:
    • trouble sleeping
    • acting aggressively or violently, or feeling more angry than usual
    • drooling
  • Can occur with Banzel:
    • dizziness
  • Can occur with both Onfi and Banzel:
    • feeling unusually sleepy or having less energy than usual
    • decreased appetite
    • vomiting
    • ataxia (trouble controlling or coordinating your muscles)

Serious side effects

These lists contain examples of serious side effects that can occur with Onfi, with Banzel, or with both drugs (when taken individually).

Effectiveness

The only condition both Onfi and Banzel are FDA-approved to treat is seizures due to LGS, when used with other medicationsfor seizures.

These drugs haven’t been directly compared in clinical studies, but studies have found both Onfi and Banzel to be effective for treating seizures due to LGS, when used with other medications for seizures.

Costs

According to estimates on GoodRx.com, costs of Onfi and Banzelwill vary depending on your treatment plan. The actual price you’ll pay for either drug depends on your insurance plan, your location, and the pharmacy you use.

Onfi and Banzelare both brand-name drugs. But Onfi is also available as a generic drug called clobazam. This is the active drug ingredient in Onfi. There are currently no generic forms for Banzel. Brand-name medications usually cost more than generics.

You should take Onfi according to your doctor’s or healthcare provider’s instructions.

How to take Onfi tablets

You can swallow Onfi whole or break it along the score line in the middle of the tablet. You can also crush Onfi tablets to mix in applesauce.

When to take Onfi tablets

When you take your Onfi tablets will depend on your dose. If your total daily dose of Onfi is more than 5 mg, then you’ll take Onfi twice a day. This will be the case for most people. (See the “Onfi dosage” section above for details.) Taking one dose in the morning and another in the evening tends to work best at helping you remember to take both doses.

To help make sure you don’t miss a dose, try setting a reminder on your phone. A medication timer may be useful, too.

How to use Onfi liquid solution

Taking the Onfi oral suspension (liquid solution) is a bit different than taking Onfi tablets.

You’ll take the oral suspension by swallowing it. But this form of the drug comes with an oral syringe that you’ll use to take your dose. It’s very important that you use only this syringe and not a spoon to measure the medication. You shouldn’t use your Onfi syringe for anything other than measuring your dose of the drug.

For a step-by-step guide and photos on how to take the oral suspension, see the drug maker’s instructions.

When to use Onfi liquid solution

When you take your Onfi liquid solution will depend on your dose. If your total daily dose of Onfi is more than 5 mg, then you’ll take Onfi twice a day. This will be the case for most people. (See the “Onfi dosage” section above for details.) Taking one dose in the morning and another in the evening tends to work best at helping you remember to take both doses.

To help make sure you don’t miss a dose, try setting a reminder on your phone. A medication timer may be useful, too.

Taking Onfi with food

You can take Onfi tablets and the oral suspension with or without food.

Can Onfi tablets be crushed, split, or chewed?

If needed, you can break Onfi along the score line in the middle of the tablet. You can also crush Onfi tablets to mix in applesauce.

Onfi is approved to treat seizures in people with a type of epilepsy known as Lennox-Gastaut Syndrome (LGS). For this use, Onfi is used as an adjunctive treatment. This means you’ll take the drug with other epilepsy medications.

Seizures are changes in the electrical activity of your brain. And epilepsy is a condition in which you have seizures repeatedly. With LGS, the seizures cause cognitive function to worsen over time. Cognitive function includes mental actions such as thinking, memory, and attention.

Onfi contains the drug clobazam. It’s not known exactly how Onfi works to reduce the number of seizures people have. During a seizure, abnormal signals are sent from the brain to the rest of the body. It’s thought that Onfi may work on certain pathways in the brain, preventing these signals from being made or sent.

How long does it take to work?

Onfi begins working as soon as you take your dose. But you may not feel the drug working right away. It could take a few days or even 1 to 2 weeks for Onfi to have its full effect, especially when you first start your treatment. This is because you’ll likely start with a low dose of the drug and work your way up to a higher dose over time.

Onfi may not be safe to use during pregnancy. The use of Onfi later in pregnancy may result in complications in newborns, including breathing and feeding problems. Newborns may also experience withdrawal from the drug because Onfi can cause you to become dependent on it. (For more about becoming dependent on Onfi, see the “Onfi withdrawal and dependence” section below.)

Animal studies

Currently, there isn’t much data on the use of Onfi during pregnancy. In animal studies, pregnant animals that were given Onfi had babies with a lower body weight and a higher risk for birth defects. Some pregnant animals that were given high doses of Onfi miscarried.

Floppy baby syndrome

A condition called floppy baby syndrome (FBS) wasn’t reported in clinical trials of Onfi. But since Onfi came onto the market, there have been rare reports of FBS in babies whose mothers took Onfi while pregnant. FBS is a condition that causes problems with muscle control. It’s not known how often FBS has occurred in pregnant mothers who took Onfi.

Pregnancy registry

If you’re using Onfi and become pregnant, ask your doctor about the North American Antiepileptic Drug Pregnancy Registry. This program helps collect data on the safety of using epilepsy drugs during pregnancy. You can find out more information by visiting the program website.

If you’re pregnant or are planning to become pregnant, talk with your doctor before using Onfi. They can review the pros and cons of the medication with you.

Onfi may not be safe to use during pregnancy.

If you use hormonal contraception (birth control that contains hormones), keep in mind that Onfi may make it less effective. This is because Onfi can speed up how quickly your body processes hormonal contraception. With a lower level of hormonal contraception in your body, you have an increased risk for becoming pregnant.

To learn more about how Onfi affects hormonal contraceptives, see the “Onfi and hormonal birth control” section above.

Talk with your doctor

If you’re sexually active and you or your partner can become pregnant, talk with your doctor about your birth control needs before you start using Onfi.

For more information about taking Onfi during pregnancy, see the “Onfi and pregnancy” section above.

Onfi may not be safe to use while nursing.

Onfi passes into human breast milk. This can cause side effects in breastfed children, including unusual sleepiness and lack of energy, and a poor ability to suck during feedings. In the short-term, these problems aren’t expected to cause harm. But over time, the problems can cause children to be sedated (overly sleepy or lacking in energy) or not gain weight.

If you’re breastfeeding or plan to breastfeed your child, tell your doctor. They can decide if taking Onfi is the best option for you.

If you have more questions about breastfeeding while taking Onfi, talk with your doctor.

Here are answers to some frequently asked questions about Onfi.

Will Onfi cure my seizures?

Currently, there isn’t a cure for seizures, so Onfi won’t cure them. But clinical studies have shown that the drug may help reduce the number of seizures in people with Lennox-Gastaut syndrome (LGS). In people with LGS who took Onfi, the number of seizures they had each week dropped by 41.2% to 68.3%, depending on the dose they took.

If you have more questions about treatment options for seizures, talk with your doctor.

Is Onfi addictive?

Yes, Onfi can be addictive. But it’s important to note that there’s a difference between being addicted to a drug and being physically dependent on it.

When you’re addicted to a drug, you aren’t able to keep from taking the drug on a consistent basis, even though using the drug has negative effects on your life. Onfi can be taken for inappropriate uses, like getting high. And misusing Onfi can lead to addiction.

When you’re physically dependent on a drug, your body has become used to the drug being in your system. Your body requires the drug to feel normal. You can become physically dependent on a drug, such as Onfi, even when your doctor has prescribed it and you’re using it as directed. If you stop taking the drug, you can experience withdrawal side effects, such as headache, tremors, and anxiety.

For more information on withdrawal and dependence on Onfi, see the section below titled “Onfi dependence and withdrawal.”

Is Onfi is a controlled substance?

Yes. Onfi is a controlled substance, which is a medication whose use is specially regulated under federal law. The Drug Enforcement Administration (DEA) places medications into “schedules” based on several factors. These factors include the medical uses for the drug, the drug’s known safety risks, and the drug’s potential for misuse. The schedules range from Schedule 2 (the most severe) to Schedule 5 (the least severe). Drugs that don’t appear to have potential for misuse won’t have a schedule at all.

Onfi is a Schedule 4 medication. This means that although Onfi has a risk of misuse and causing you to become dependent on it, the risk is lower compared with other controlled substances.

Onfi contains the active drug clobazam, which belongs to a class of medications called benzodiazepines. (A class of medications is a group of drugs that work in a similar way.) These medications have a high risk of misuse and addiction. And if you use too much of them, they can also cause dangerous side effects including coma, and in some cases, death. The use of benzodiazepines with other drugs, including alcohol, can also cause these dangerous side effects.

If you have any concerns about using Onfi, talk with your doctor.

Will I have withdrawal symptoms if I stop taking Onfi?

It’s possible to have withdrawal symptoms, especially if you suddenly stop taking Onfi. Instead, Onfi use needs to be tapered off gradually. Your doctor will do this by slowly decreasing your dose over time. You shouldn’t stop taking Onfi without first talking with your doctor.

For more information, see the section “Onfi withdrawal and dependence” below.

Is Onfi the same as Xanax?

No, Onfi isn’t the same as Xanax.

Onfi contains the active drug clobazam. Xanax contains the active drug alprazolam. Both clobazam and alprazolam belong to a class of medications called benzodiazepines. (A medication class is a group of drugs that work in a similar way.)

Although the two drugs belong to the same medication class, they’re used for different conditions. The Food and Drug Administration (FDA) has approved Onfi to treat seizures in people with LGS, when used with other seizure medications.

Xanax is FDA-approved to treat anxiety disorders or for short-term treatment of anxiety symptoms. Xanax is also approved to treat panic disorder. This is a condition in which you’ve had repeated panic attacks of sudden, intense fear and are afraid of having them again.

Can I drive while taking Onfi?

Maybe. Onfi is a type of drug called a central nervous system (CNS) depressant, which can make you drowsy and sleepy. So you should avoid any activity that requires you to be mentally alert until you know how Onfi will affect you. This includes driving a car or using heavy machinery. For more information, see the “Severe drowsiness” section above.

This drug comes with several precautions.

FDA warning: Onfi use with opioids

This drug has a boxed warning. This is the most serious warning from the Food and Drug Administration (FDA). A boxed warning alerts doctors and patients about drug effects that may be dangerous.

The use of Onfi with medications known as opioids can cause severe side effects. These effects can include sedation (extreme drowsiness or tiredness) and respiratory depression (slow and weak breathing). They can also include coma, and, in some cases, death.

Your doctor will prescribe Onfi with an opioid only when no other treatments will work for you. And if you do use Onfi with an opioid, you should take the lowest dose of Onfi that’s effective for you. Your doctor will monitor you for symptoms of sedation and respiratory depression during your Onfi treatment.

Other precautions

Before taking Onfi, talk with your doctor about your health history. Onfi may not be right for you if you have certain medical conditions or other factors affecting your health. These include:

  • Liver problems. If you have liver problems, your doctor may have you try a lower dose of Onfi to start. For more information, talk with your doctor.
  • Kidney problems. If you have severe kidney problems or are on dialysis, talk with your doctor before using Onfi. They may want you to use a different drug instead.
  • Mood problems, depression, or suicidal thoughts or behaviors. Onfi can increase your risk for mood problems, depression, and suicidal thoughts or behaviors. So if you had or have any of these issues, your doctor will want to monitor you during your Onfi treatment. Talk with them about your mental health before taking Onfi. Your doctor will work with you to determine the best treatments for you.
  • Allergic reaction. If you’ve had an allergic reaction to Onfi or any of its ingredients, you shouldn’t take Onfi. Ask your doctor what other medications are better options for you.
  • Pregnancy. Onfi may not be safe to use during pregnancy. For more information, please see the “Onfi and pregnancy” section above.
  • Breastfeeding. Onfi may not be safe to use while breastfeeding. For more information, please see the “Onfi and breastfeeding” section above.

Note: For more information about the potential negative effects of Onfi, see the “Onfi side effects” section above.

Using more than the recommended dosage of Onfi can lead to serious side effects.

Overdose symptoms

Symptoms of an overdose can include:

What to do in case of overdose

If you think you’ve taken too much of this drug, call your doctor. You can also call the American Association of Poison Control Centers at 800-222-1222 or use their online tool. But if your symptoms are severe, call 911 or go to the nearest emergency room right away.

Onfi can be addictive and cause you to become physically dependent on the drug.

When you’re addicted to a drug, you aren’t able to keep from taking the drug on a consistent basis, even though using the drug has negative effects on your life. Onfi can be taken for inappropriate uses, like getting high. And misusing Onfi can lead to addiction.

When you’re physically dependent on a drug, your body has become used to the drug being in your system. Your body requires the drug to feel normal. You can become physically dependent on a drug even when your doctor has prescribed it and you’re using it as directed. If you stop taking the drug, you can experience withdrawal side effects (see the list below).

Withdrawal symptoms

Stopping your Onfi treatment suddenly can cause you to have withdrawal symptoms, which can include:

Because of these possible withdrawal symptoms, it’s very important that you don’t suddenly stop taking Onfi. Instead, your doctor will have you gradually stop taking the drug over time. This is known as “tapering” the drug. Your doctor will slowly decrease your Onfi dose over time until it’s safe for you to stop taking the drug entirely.

If you have any concerns about using Onfi, talk with your doctor.

When you get Onfi from the pharmacy, the pharmacist will add an expiration date to the label on the bottle. This date is typically 1 year from the date they dispensed the medication.

The expiration date helps guarantee that the medication is effective during this time. The current stance of the Food and Drug Administration (FDA) is to avoid using expired medications. If you have unused medication that has gone past the expiration date, talk to your pharmacist about whether you might still be able to use it.

Storage

How long a medication remains good can depend on many factors, including how and where you store the medication.

You should store both Onfi tablets and the liquid suspension between 68°F and 77°F (20°C and 25°C).

Keep the Onfi liquid suspension in the original bottle, stored upright and tightly closed. You should use it within 90 days of first opening the bottle. After 90 days, dispose of any liquid suspension that’s leftover.

Avoid storing this medication in areas where it could get damp or wet, such as bathrooms.

Disposal

If you no longer need to take Onfi and have leftover medication, it’s important to dispose of it safely. This helps prevent others, including children and pets, from taking the drug by accident. It also helps keep the drug from harming the environment.

This article provides several useful tips on medication disposal. You can also ask your pharmacist for information on how to dispose of your medication.

The following information is provided for clinicians and other healthcare professionals.

Indications

Onfi (clobazam) is approved by the Food and Drug Administration (FDA) for the adjunctive treatment of seizures related to Lennox-Gastaut syndrome (LGS) in adults as well as children ages 2 years and older.

Administration

Onfi tablets can be taken with or without food. Onfi tablets are scored and may be divided in half. Onfi tablets may also be crushed for mixing in applesauce.

Onfi liquid suspension can be taken with or without food. Instruct patients to shake it well before each use. Only the provided oral dosing syringe should be used for administration.

Onfi tablets and liquid suspension are both administered by mouth.

Mechanism of action

The exact mechanism of action for clobazam isn’t known. It is believed to bind to the benzodiazepine site on the gamma-aminobutyric acid (GABA) A receptor and potentiate GABA neurotransmission.

Pharmacokinetics and metabolism

Clobazam reaches peak concentrations approximately 30 minutes to 4 hours following administration. Relative bioavailability of tablets compared with the oral solution is nearly 100%.

Clobazam is converted to an active metabolite, N-desmethylclobazam, primarily in the liver by CYP3A4, CYP2C19, and CYP2B6. N-desmethylclobazam has approximately 1/5 the activity of clobazam.

The approximate half-lives for clobazam and N-desmethylclobazam are 36 to 42 hours and 71 to 82 hours, respectively.

Clearance of clobazam is decreased in older patients, and lower starting doses should be used as a result.

Contraindications

Onfi is contraindicated in patients who have demonstrated hypersensitivity to either the drug or any ingredients of the drug product.

Misuse, dependence, and withdrawal

Do not abruptly discontinue Onfi. Withdrawal symptoms have occurred after abrupt discontinuation. If discontinuing Onfi, taper the dose each week by 5 to 10 mg/day.

If used in patients with a history of substance misuse, monitor the patient carefully. Onfi can cause physical and psychological dependence.

Storage

Both Onfi tablets and the oral suspension should be stored between 68°F to 77°F (20°C to 25°C). The Onfi oral suspension should be kept in the original bottle and stored upright. The oral suspension should be used within 90 days of first opening the bottle; any remainder after this point should be disposed of.

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.