Klonopin (Clonazepam) – Oral

Warning:

Klonopin (clonazepam) is a type of drug called a benzodiazepine. Using benzodiazepines and opioids at the same time can be dangerous, resulting in excessive sedation, breathing difficulties (respiratory depression), coma, and even death. Therefore, it is strongly advised to avoid taking these two medications together. If using them together is necessary, your healthcare provider will advise you on how to take them and watch for signs of respiratory depression and sedation.

Benzodiazepines can also increase the risk of misuse, physical dependence, and addiction. Withdrawal is possible if abruptly stopping Klonopin after continued use results in physical dependence. Talk to your healthcare provider about safely stopping this medication if needed.


What Is Klonopin?

Klonopin (clonazepam) belongs to a class of drugs called benzodiazepines and is used primarily to treat panic disorder or seizures (called epilepsy). It works by increasing the effects of a “calming” chemical called gamma-aminobutyric acid (GABA) in your brain.

Due to its potential for dependence and misuse, clonazepam is classified as a Schedule IV controlled substance.

This prescription medication is available as a tablet to swallow whole or a tablet that dissolves on the top of your tongue.

Drug Facts

Generic Name: Clonazepam

Brand Name(s): Klonopin

Drug Availability: Prescription

Administration Route: Oral

Therapeutic Classification: Benzodiazepine

Available Generically: Yes

Controlled Substance: Schedule IV

Active Ingredient: Clonazepam

Dosage Form(s): Tablet, orally disintegrating tablet

What Is Klonopin Used For?

The Food and Drug Administration (FDA) approved Klonopin to treat adults with panic disorder who may or may not have agoraphobia (a fear of open spaces). Klonopin also treats certain seizure disorders in adults and children, such as:

  • Lennox-Gastaut syndrome: A severe form of epilepsy that includes different types of seizures, such as tonic (stiffening) and atonic (drop) seizures. This condition typically emerges in infancy or early childhood.
  • Akinetic, also known as atonic, seizures: These seizures occur when the muscles suddenly become limp. A person who is standing while having an akinetic seizure can fall to the ground and become injured.
  • Myoclonic seizures: Brief, shock-like jerks that affect a muscle or group of muscles. In epilepsy, these seizures may cause abnormal movements on both sides of the body simultaneously.

How to Take Klonopin

Klonopin is taken by mouth, with or without food, depending on your preference.

If you take the tablet form, you will want to swallow the pill whole with a glass of water.

If you take the orally disintegrating tablet, remove the tablet from the blister foil pack with dry hands when you're ready to use it. When removing the tablet, peel the foil backing off the blister, gently remove the tablet, and place it on the top of your tongue. You do not need to drink water (although you can if you prefer), as the tablet will melt within seconds on its own.

When taking Klonopin, remember the following:

  • To avoid oversedation, do not take Klonopin with alcohol or any drugs that can make you sleepy or dizzy (e.g., opioids or marijuana).
  • Klonopin can also impair your judgment or motor skills. Avoid driving or operating machinery (e.g., lawnmowers) until you know how it affects you.
  • Never stop taking Klonopin suddenly, as this puts you at risk for developing severe withdrawal symptoms, including hallucinations, shaking, stomach pain, and a potentially fatal condition called status epilepticus.

If you have questions about Klonopin or you feel it isn't working as well as it did in the past, reach out to your healthcare provider as soon as possible.

Storage

Store your Klonopin at room temperature (between 68 and 77 degrees F) and make sure that it is out of reach of children and pets.

Off-Label Uses

Healthcare providers can prescribe Klonopin off-label to treat various health problems. Off-label use means that even if Klonopin is not FDA-approved for that particular condition, healthcare providers can still prescribe it if they deem it medically appropriate.

Off-label uses of Klonopin include:

How Long Does Klonopin Take to Work?

Klonopin reaches peak blood levels within one to four hours. The drug may start to work within hours or days of taking the first dose.

What Are the Side Effects of Klonopin?

This is not a complete list of side effects, and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your healthcare provider. You may report side effects to the FDA at fda.gov/medwatch or 800-FDA-1088.

Common Side Effects

The most common side effects of taking Klonopin are:

  • Drowsiness 
  • Dizziness
  • Problems with walking and balance
  • Depression
  • Tiredness
  • Memory difficulties 
  • Increased saliva production

Severe Side Effects

Call your healthcare provider immediately if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency.

A small number of individuals may have a severe reaction to Klonopin and develop symptoms like:

  • Aggressiveness or being violent or angry
  • Unusual agitation or restlessness
  • Panic attacks
  • Trouble sleeping
  • New or worsening anxiety
  • Extreme increase in talking or activity
  • Nightmares or psychosis

These seemingly contradictory reactions are more likely to occur in children, adults 65 years and older, and those with a history of a psychological condition.

Other potentially serious side effects of Klonopin include:

  • Thoughts about suicide, dying, or self-harm, or attempting to commit suicide
  • New or worsening depression
  • Trouble breathing 
  • New or worsening seizure activity
  • Signs of an allergic reaction (e.g., rash, swelling of the face, eyes, lips, or tongue, or difficulty in breathing)

Long-Term Side Effects

People taking Klonopin daily for an extended time (two weeks or more) may develop a physical or emotional dependence on the drug. Suddenly stopping Klonopin can result in unpleasant withdrawal symptoms.

Withdrawal symptoms from Klonopin can include:

  • Hallucinations
  • Shaking
  • Stomach or muscle cramping 
  • Trouble sleeping
  • Feeling down or depressed 
  • Seizures
  • Nausea
  • Excessive sweating
  • Thoughts of suicide
  • Confusion

To prevent the above symptoms, your healthcare provider will slowly decrease or taper your dose over several days or weeks when you are ready to stop Klonopin.

Report Side Effects

Klonopin may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your healthcare provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

Dosage: How Much Klonopin Should I Take?

Drug Content Provided and Reviewed by IBM Micromedex®

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage forms (tablets or disintegrating tablets):
    • For seizures:
      • Adults and children 10 years and older—At first, 0.5 milligram (mg) 3 times per day. Your doctor may adjust your dose as needed. However, the dose is usually not more than 20 mg per day.
      • Children up to 10 years or 30 kilograms (kg) of body weight—Dose is based on body weight and must be determined by your doctor. The dose is usually 0.01 to 0.03 mg per kg of body weight per day, given in 2 or 3 divided doses. However, the dose is usually not more than 0.05 mg per kg of body weight. Your doctor may adjust your dose as needed.
    • For panic disorder:
      • Adults—At first, 0.25 milligram (mg) 2 times per day. Your doctor may adjust your dose as needed. However, the dose is usually not more than 4 mg per day.
      • Children—Use and dose must be determined by your doctor.

Modifications

Dosing for children is based on age and body weight, with the lowest dose being administered to children under 10 years old or weighing less than 66 pounds (30 kilograms), whichever comes first.

There are no specific Klonopin dosing adjustments for individuals 65 years and older. That said, older adults are usually started on low doses and monitored carefully by their healthcare provider for signs of oversedation. 

If you are pregnant or planning on becoming pregnant while taking Klonopin, talk to your healthcare provider right away. Taking Klonopin while pregnant may cause harm to the fetus. Your healthcare provider will advise you on how and when to stop or continue the drug safely. 

Keep in mind that if you take Klonopin and become pregnant, you will likely be asked to enroll in a registry that collects information about the safety of anti-seizure medications during pregnancy. 

Also, inform your healthcare provider if you are planning on or are currently breastfeeding. Klonopin does pass into breast milk, so there is a potential for side effects in the baby.

Missed Dose

If you miss a dose of Klonopin, take it as soon as you remember unless it's close to your next dose. In that case, skip your missed dose and take the Klonopin at the next regularly scheduled time. Do not double up on doses to make up for the missed dose.

If you miss Klonopin doses often, consider using a calendar or pillbox or setting the alarm on your phone or watch. You could also consider asking a loved one or friend to check in with you about taking your Klonopin on time.

Overdose: What Happens If I Take Too Much Klonopin?

Symptoms of a Klonopin overdose include: 

  • Excessive sleepiness
  • Confusion
  • Slow reflexes
  • Coma

A medication called flumazenil may reverse the effects of a Klonopin overdose. However, it can only be given through an IV (intravenously, administered into the vein) at a hospital and cannot be used in individuals with epilepsy.

What Happens If I Overdose on Klonopin?

If you think you or someone else may have overdosed on Klonopin, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses or isn't breathing after taking Klonopin, call 911 immediately.

Precautions

Drug Content Provided and Reviewed by IBM Micromedex®

It is very important that your doctor check your progress at regular visits to see if the medicine is working properly and to allow for changes in the dose. Blood tests may be needed to check for unwanted effects.

Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. If you think you have become pregnant while using the medicine, tell your doctor right away.

This medicine may be habit-forming. If you feel that the medicine is not working as well, do not use more than your prescribed dose. Call your doctor for instructions.

This medicine may cause drowsiness, trouble with thinking, trouble with controlling movements, or trouble with seeing clearly. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert or able to think or see well.

If you develop any unusual and strange thoughts or behavior while you are taking clonazepam, be sure to discuss it with your doctor. Some changes that have occurred in people taking this medicine are like those seen in people who drink alcohol and then act in a manner that is not normal. Other changes may be more unusual and extreme, such as confusion, worsening of depression, hallucinations (seeing, hearing, or feeling things that are not there), suicidal thoughts, and unusual excitement, nervousness, or irritability.

If you have been taking this medicine for a long time, do not stop taking it without checking first with your doctor. Your doctor may want you to gradually reduce the amount you are using before stopping it completely. This may help prevent worsening of your condition and reduce the possibility of withdrawal symptoms, iincluding actions that are out of control, anxiety, blurred vision, decreased awareness or responsiveness, discouragement, dizziness, environment seems unreal, feeling of unreality, feeling sad or empty, irritability, lack of appetite, loss of interest or pleasure, mimicry of speech or movements, mutism, negativism, nervousness, peculiar postures or movements, mannerisms or grimacing, seeing, hearing, or feeling things that are not there, sense of detachment from self or body, seizures, severe sleepiness, talking, feeling, and acting with excitement, trouble concentrating and sleeping.

Symptoms of an overdose include: change in consciousness, lack of coordination, loss of consciousness, mood or mental changes, or sleepiness or unusual drowsiness. Call your doctor right away if you notice these symptoms.

This medicine will add to the effects of alcohol and other central nervous system (CNS) depressants. CNS depressants are medicines that slow down the nervous system, which may cause drowsiness or make you less alert. Some examples of CNS depressants are antihistamines or medicine for hay fever, allergies or colds, sedatives, tranquilizers, or sleeping medicine, prescription pain medicine or narcotics, barbiturates or seizure medicines, muscle relaxants, or anesthetics (numbing medicines), including some dental anesthetics. Check with your doctor before taking any of these products while you are using this medicine.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

What Are Reasons I Shouldn’t Take Klonopin?

You should not take Klonopin if you have any of the following conditions:

In addition, people with porphyria should be cautious when taking Klonopin, as it can worsen their condition when used at high doses. Klonopin should also be used cautiously in people with breathing disorders like chronic obstructive pulmonary disease (COPD). It can cause slow and shallow breathing.

Lastly, Klonopin is a controlled substance that can be habit-forming and lead to dependence. As a result, people who have abused or been dependent on alcohol, prescription medications, or recreational drugs should be cautious when using it.

What Other Medications Interact With Klonopin?

Since Klonopin causes drowsiness, it is not recommended to take it with alcohol or other medications that also cause drowsiness, unless specifically instructed to by your healthcare provider.

Other medications that cause drowsiness include:

In addition, oral antifungal medications like Diflucan (fluconazole) can increase the blood levels of Klonopin in your body, putting you at higher risk of side effects.

Certain antiepileptic medications, including Tegretol (carbamazepine), can decrease the blood levels of Klonopin in your body, which reduces how well Klonopin works.

If you take a medicine that interacts with Klonopin, your healthcare provider may need to adjust your dose or prescribe an alternative therapy.

The list above is not complete. Inform your healthcare provider of all the medications you take, including prescription and over-the-counter (OTC) drugs, herbal products, supplements, vitamins, and recreational drugs.

What Medications Are Similar?

Benzodiazepines all act in the same manner, but they vary in potency, time to onset, and metabolism in the body.

Besides Klonopin, other benzodiazepines used to either prevent and control seizures or treat panic disorder include:

Like Klonopin, Valium is long-acting, which means the drug is metabolized slowly and takes longer to leave the body. Ativan and Xanax, on the other hand, are intermediate-acting. Klonopin is often the preferred agent for treating anxiety (compared to Ativan or Xanax) because it lasts longer and may require less frequent dosing. However, it is not preferred for use in adults 65 and older because it is extensively metabolized in the liver and may be more likely to cause side effects.

Keep in mind that you should not take Klonopin with another benzodiazepine. Talk to your pharmacist or a healthcare practitioner if you have questions.

Frequently Asked Questions

  • What is Klonopin used for?

    The FDA approved Klonopin to treat certain types of epilepsy in adults and children and panic disorder with or without agoraphobia in adults. Klonopin is also sometimes prescribed off-label to treat acute anxiety, insomnia, and restless legs syndrome, among other conditions.

  • How does Klonopin work in your body?

    Klonopin is a benzodiazepine and, like other drugs in its class, works by increasing the activity of a brain chemical called gamma-aminobutyric acid (GABA).

    GABA normally blocks the signaling of nerve cells involved in producing anxiety, arousal, and seizure activity. By enhancing the activity of GABA, Klonopin reduces seizure activity and makes you feel calm and relaxed.

  • How do I safely stop taking Klonopin?

    Do not abruptly stop taking Klonopin, especially if you have taken it for over a month. Instead, your healthcare provider should gradually decrease your Klonopin dose over time (tapering).

    Suddenly stopping Klonopin can be a shock to your system and cause severe withdrawal symptoms, including stomach and muscle cramping, shaking, abnormal dreams, nausea, sweating, headaches, and seizures.

    When tapering off Klonopin, follow your healthcare provider’s instructions. Your tapering schedule may last days to months, depending on factors like your starting dose and how long you were taking Klonopin.

  • What are the side effects of Klonopin?

    The most common side effects associated with Klonopin are:

    • Drowsiness or dizziness
    • Problems with walking and balance
    • Depression
    • Fatigue
    • Memory difficulties

    Contact a healthcare professional if these side effects persist, get worse, or are not tolerable.

    Serious side effects of Klonopin are not common but require immediate medical attention and include:

    • Suicidal ideation
    • Paradoxical reaction (e.g., unusual agitation or restlessness, hallucinations, or mania)
    • Trouble breathing
    • New or worsening depression or seizure activity
    • Allergic reaction (e.g., rash or swelling of the face, eyes, lips, or tongue)

How Can I Stay Healthy While Taking Klonopin?

Before starting Klonopin, have an open discussion with your healthcare provider about why this medication is safe and reasonable for you to take. During your conversation, be honest about your medical history, including any history of medication/drug/alcohol abuse or dependence. 

Take Klonopin exactly as advised. If you are taking it for seizures or panic attacks, keep in mind that your brain needs a constant and steady stream of medication to prevent them from occurring. 

Remember to not stop Klonopin on your own, even if it does not seem to be working well for you. A fast drop in the level of Klonopin in your bloodstream can trigger serious withdrawal symptoms. Instead, if you feel like the drug isn’t working or is causing bothersome side effects, contact your healthcare provider. Together, you can come up with an alternative and healthy treatment plan.

Lastly, whatever the reason you are taking Klonopin, remain an active participant in your overall health. Attend all of your medical appointments, eat a nutritious diet, stay active, and find emotional support and comfort through interactions with loved ones, friends, or a support group.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended to replace medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

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By Colleen Doherty, MD
 Colleen Doherty, MD, is a board-certified internist living with multiple sclerosis.