What You Need to Know About Clobazam

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Clobazam, also referred to as Onfi, is an older anti-seizure (anticonvulsant) medication. It belongs to the class of drugs called benzodiazepines, and it’s known to be less sedating than other drugs in the same category because its chemical structure differs slightly, according to a review on the medication in the journal Pediatric Reports. Additionally, the drug may be better tolerated than other anti-seizure medications, particularly with those used to treat epilepsy.

Clobazam may be used in conjunction with other medications by adults and children 2 years of age or older to control seizures.

To use clobazam, you must obtain a prescription from your doctor, and it comes in a 10 milligram (mg) and 20 mg tablet, and 2.5 mg liquid. The dose of the medication will differ from one person to the next.

Why Is It Used?

Most notably, clobazam is used in Lennox-Gastaut syndrome, a serious form of epilepsy that can present with several types of seizures and intellectual and developmental disabilities. The drug works by reducing the brain’s atypical electrical activity that can lead to seizures.

Furthermore, benzodiazepines have often been used to treat anxiety—and there may be some instances where clobazam is prescribed for this condition. In December 2017, the Kennedy Krieger Institute in Baltimore, Maryland announced a clinical trial to explore the use of clobazam in pediatric patients who have a diagnosis of epilepsy and “clinically significant” anxiety that impairs daily life to assess whether it improves outcomes for both conditions.

Besides seizures and anxiety, there may be others uses and conditions for which the doctor prescribes you this medication.

How Is It Taken?

Your doctor will likely start you on a low dose of the medication and work up to a higher dose every couple of weeks. Although your doctor will provide you with instructions as to how to take the medication, the following are some general recommendations as to how the drug is taken:

  • Clobazam is usually taken once or twice a day, and it can be taken with or without food.
  • When taking the medication, you’ll want to stick to a schedule and try to take it at the same time each day.
  • If you have trouble swallowing the pills, you can crush them up and place them in applesauce.
  • Don’t take more or less of the prescribed amount of the medication.
  • If you miss a dose, take the next dose as soon as you can. If it’s close to the time you take your next dose, skip the missed dose and resume your medication as prescribed.
  • Don’t stop taking your medication without first speaking to your doctor.
  • If you’re taking clobazam in liquid form, you may have particular guidelines to follow, such as shaking the bottle to mix the drug before use, using the adapter and syringe to measure out the correct amount of medication, storing the medication at room temperature, or other specific instructions.  

Side Effects

You may experience some unwanted side effects when taking clobazam. The side effects can range from mild to severe. Although one person’s experience with the medication will likely be different than another person’s, the following are some mild side effects that can be associated with the drug, as reported by the U.S. National Library of Medicine of the National Institutes of Health (NIH):

  • Fatigue
  • Impaired coordination
  • New onset of difficulty speaking or swallowing
  • Drooling
  • Pain in the muscles or joints
  • Nausea and vomiting
  • Reduction in appetite
  • Changes in bowel habits such as constipation
  • A cough that coincides with the start of the medication

Serious Side Effects

Serious side effects can occur and warrant an immediate call to your physician or emergency care. Examples of these side effects include:

  • Changes in urination, such as bladder pain, difficulty voiding, and increased urinary frequency
  • Trouble breathing
  • Rashes, such as hives, or peeling or blistering of the skin
  • Fever or elevated temperature
  • Sores appear in the mouth

Additionally, clobazam can cause potentially life-threatening skin reactions like Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN)—two severe dermatological diseases that are characterized by rashes, peeling of the skin, and sores on the mucous membranes. Both diseases may also include flu-like symptoms such as fever and body aches, according to the Merck Manual.

Should you experience these side effects, you need immediate, emergency medical care.

Precautions and Contraindications

If you’ve had an allergic reaction to clobazam in the past, are allergic to the ingredients that make up the drug, or have had reactions to other benzodiazepine medications, you may not be a good candidate for this medication. Talk to your doctor about alternatives.

Be sure to let your doctor know if you’re taking other prescription medications (including birth control), over-the-counter-drugs, vitamins, supplements, and herbs. These may interfere with the efficacy of the drug, and your doctor may need to adjust your dose accordingly and monitor you for the presence of side effects.

Let your doctor know if you are pregnant, breastfeeding, or planning to get pregnant. At this time, there’s a lack of well-controlled studies on clobazam and its impact on pregnant women. The drug is listed as a pregnancy category C, which indicates the drug should be used with caution providing the benefits of using it outweigh the risks.

If you have any questions regarding clobazam and pregnancy, talk with your doctor.

Other Information

To ensure that the medication is achieving the desired outcome, your health care provider will want to schedule regular checkups to monitor your progress.

Additionally, talk to your doctor about whether or not you should consume alcohol, which compounds the drug’s effects on the central nervous system (CNS) and may increase feelings of drowsiness and fatigue, as well as decrease alertness. Before driving or using machinery, make sure you understand how your body reacts to the medication to keep you and others around you safe.

A Word From Verywell

Anytime you begin a new medication, it’s natural to have questions and concerns. If you’re uncertain about taking clobazam, be sure to ask your doctor or pharmacist to clarify anything you don’t understand. Also, if you experience lingering side effects that don’t go away or interfere with your life, be sure to consult with your doctor as soon as possible so that you and your health care provider can discuss which treatment options may be right for you.

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