Clonazepam (kloe NAZ e pam) has been approved by the FDA to treat Lennox-Gastaut syndrome (tonic-clonic variant), akinetic, and myoclonic seizures, both alone or as adjunctive treatment. In patients with absence seizures (petit mal) who have failed to respond to succinimides, clonazepam may be useful.

Your epilepsy treatment should always be discussed with your healthcare provider before use. Based on their judgment and knowledge, a drug may be prescribed for other epilepsy types not included in the indications. For more information, please see the prescribing information.

How can you take clonazepam? (Available formulations)

Clonazepam is available as a tablet taken whole or orally disintegrating tablet (wafer) with or without water.

Who should not take clonazepam?

If you are allergic to clonazepam or any of the inactive ingredients, then you should not take it. Clonazepam should not be taken if you have significant liver disease or acute narrow-angle glaucoma.

Other considerations may influence whether you should take clonazepam. Tell your healthcare provider if you:

  • have kidney problems.
  • have liver problems.
  • have lung problems.
  • have or have had depression, mood problems, or suicidal thoughts or behavior.
  • are pregnant or plan to become pregnant.
  • are breastfeeding or plan to breastfeed.

What is important to know about taking clonazepam?

Do not stop taking clonazepam suddenly unless directed to do so by your healthcare provider.

As with all antiseizure medications, clonazepam should be withdrawn gradually to minimize the risk of causing or worsening seizures or status epilepticus. You should not stop using clonazepam suddenly unless your healthcare provider tells you to stop the medicine because of a serious side effect.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

Taking clonazepam with certain other medicines may cause side effects or affect how well they work. Do not start or stop other medicines without talking to your healthcare provider. Especially tell your healthcare provider if you take: drugs that cause sleepiness or dizziness or St. John’s wort.

Boxed Warning

Clonazepam is approved by the FDA because it is safe and effective for the majority of people who take it. However, there are risks associated with all medicines. Some side effects caused by clonazepam can be very serious, and even life-threatening. It is important to be informed about these serious reactions and to be aware of their symptoms.

Use with opioids or other central nervous system depressants

Clonazepam can slow or stop your breathing, especially if you have recently used an opioid medication, alcohol, or other central nervous system depressants as they also may slow your breathing. If you are administered clonazepam, your healthcare providers will watch you for symptoms such as weak or shallow breathing.

Tell your healthcare provider right away if you have:

  • weak or shallow breathing
  • severe drowsiness
  • restlessness or you feel agitated or irritable
  • unusual thoughts, hallucinations
  • a light-headed feeling, like you might pass out

Get emergency help right away if you experience shallow or slowed breathing, breathing stops (which may lead to the heart stopping), or excessive sleepiness (sedation).

Abuse, misuse, and addiction

Clonazepam is a federally controlled substance (Schedule IV) as it has a risk of abuse, misuse, and addiction, which can lead to overdose or death. Using clonazepam more frequently than recommended, even at recommended dosages, may increase these risks, especially when used in combination with other medications (e.g., opioids), alcohol, and/or illicit substances. Talk to your healthcare provider about the signs and symptoms of clonazepam addiction.

Dependence and withdrawal reactions

The use of clonazepam more frequently than recommended may cause physical dependence. This means that stopping clonazepam suddenly can worsen your condition and cause withdrawal symptoms including irritability, sleeplessness, nervousness, and seizures. Physical dependence is not the same as drug addiction. Your healthcare provider can tell you more about the differences between physical dependence and drug addiction.

Women or those who are/plan to become pregnant

Clonazepam may hurt your baby if taken while pregnant.

Use in pregnancy

Ordinarily, clonazepam should not be used during pregnancy except in serious or life-threatening conditions where safer drugs cannot be used or are ineffective. Status epilepticus may represent such a serious and life-threatening condition. During the first trimester of pregnancy, several studies suggest the use of minor tranquilizers (chlordiazepoxide, diazepam, and meprobamate), which are similar to clonazepam, can increase the risk of birth defects. Studies have also shown in humans that clonazepam and some metabolites are transferred to the placenta.

If you become pregnant while taking clonazepam, talk to your healthcare provider about registering with the North American Antiepileptic Drug (NAAED) Pregnancy Registry. The purpose of this registry is to collect information about the safety of antiseizure medicine during pregnancy. You can enroll in this registry by calling 1-888-233-2334.

Use during breastfeeding

Clonazepam has been detected in human breast milk. Therefore, nursing people should not take clonazepam because, like other benzodiazepines, the possibility exists that clonazepam may sedate or otherwise adversely affect the infant.

What are the side effects of clonazepam?

Common side effects

The most common side effects that were reported in studies of clonazepam are drowsiness (somnolence), depression, dizziness, nervousness, problems with movement and balance (ataxia), and reduced intellectual ability.

Rare, but serious side effects
Suicidal thoughts or behaviors

Studies have found that people who take antiseizure medications including clonazepam may have suicidal thoughts or behaviors, which occur in approximately 1 in 500 patients. If you experience any thoughts or impulses to hurt yourself, you should contact your healthcare provider immediately.

Interference with cognitive and motor performance

Since clonazepam produces central nervous system depression, patients receiving this drug should be cautioned against engaging in hazardous occupations requiring mental alertness, such as operating machinery or driving a motor vehicle. They should also be warned about the concomitant use of alcohol or other CNS-depressant drugs during clonazepam therapy.