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Clonazepam for epilepsy

Clonazepam is prescribed to treat epilepsy. It may cause you to feel sleepy, particularly when you first start taking it, and it is likely to affect your reactions. These effects can last into the following day.

Continue to take clonazepam regularly until your doctor tells you to stop. You must not stop taking it without speaking with your doctor first, as stopping suddenly will cause problems.

Do not drink alcohol whilst you are on clonazepam.

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About clonazepam

Type of medicine

A benzodiazepine anti-epileptic medicine

Used for


Available as

Tablets and oral liquid medicine

Clonazepam is used to treat epileptic disease and seizures. It can be taken by adults and by children.

If you have epilepsy, it means that you have had more than one unexplained fit, or seizure. A seizure is a short episode of symptoms caused by a burst of abnormal electrical activity in your brain. Different parts of the brain control different functions of your body, so the symptoms that occur during a seizure will depend on where the abnormal burst of electrical activity occurs. Symptoms that may occur during a seizure can affect your muscles, sensations, behaviour, emotions, and consciousness, or a combination of these. The seizures can be prevented in most people by suitable anti-epileptic medication.

Clonazepam controls the symptoms of seizures by stabilising the electrical activity of your brain, which prevents the seizures from occurring. It also relaxes muscles that stiffen, or contract, during a seizure. This means that the numbers of seizures are reduced, and those that do occur, are less severe.

Before taking clonazepam

Some medicines are not suitable for people with certain conditions, and sometimes a medicine can only be used if extra care is taken. For these reasons, before you start taking clonazepam it is important that your doctor knows:

  • If you are pregnant, trying for a baby or breastfeeding.

  • If you have any breathing problems.

  • If you have any problems with the way your liver works, or if you have any problems with the way your kidneys work.

  • If you have a mental health problem. This includes conditions such as psychosis, depression, obsessive conditions, phobias and personality disorders.

  • If you have ever had a drug or alcohol addiction.

  • If you have been told you have spinal or cerebellar ataxia. These are conditions where you have difficulty controlling your movements - you may become shaky and unsteady, and have slurred speech or rapid eye movements.

  • If you have a condition causing severe muscle weakness, called myasthenia gravis.

  • If you have a rare inherited blood disorder called porphyria.

  • If you have ever had an allergic reaction to a medicine.

  • If you are taking or using any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.

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How to take clonazepam

  • Before you start the treatment, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about clonazepam, and will also provide you with a full list of the side-effects which you could experience from taking it.

  • Take clonazepam exactly as your doctor tells you to - the dose will be individualised to suit your needs. You will be advised to take a small dose when you first start taking it and then to increase your dose over a few weeks as your body becomes used to it. Your doctor or pharmacist will explain this to you, and directions will also be printed on the label of the pack to remind you about what the doctor said to you.

  • Clonazepam is usually taken as a once-daily dose at bedtime, although some doctors may recommend that you take it divided into three or four smaller doses a day until your body has adjusted to it. Try to take clonazepam at the same time(s) each day, as this will help you to remember to take your doses regularly.

  • You can take clonazepam either with or without food. Swallow the tablet(s) with a drink of water.

  • Clonazepam is available in two strengths of tablets and several strengths of liquid medicine. Your treatment could be affected by switching between different makes of the medicine. If this is the case for you, each time you collect a new supply, check the label to make sure it is the same as you have had before or ask your pharmacist to check it out for you.

  • If you forget to take a dose at your usual time, take it as soon as you remember. If you do not remember until the following day, leave out the forgotten dose from the previous day and take the dose that is due that day as normal. Do not take two doses together to make up for a missed dose.

Getting the most from your treatment

  • Try to keep your regular appointments with your doctor. This is so your doctor can check on your progress.

  • When you first start a new treatment for epilepsy there may be a change in the number or type of seizures you experience. Your doctor will advise you about this.

  • Clonazepam can make you feel sleepy, especially when you first start treatment. Do not drink alcohol while you are on clonazepam as it will increase the likelihood that you experience this side-effect.

  • While you are being treated for epilepsy there is a small risk that you may develop mood changes, distressing thoughts and feelings about suicide. If this happens, you must tell your doctor about it straightaway.

  • People with epilepsy must stop driving at first. Your doctor will advise you about if and when it may be possible for you to start driving again. This will usually be after a year free of seizures. If you are permitted to drive, please be aware that clonazepam is likely to affect your reactions and ability to drive. It is an offence to drive while your reactions are impaired. Please also be aware that the effects of clonazepam can last into the following day. Even if your driving ability is not impaired, should you drive, you are advised to carry with you some evidence that the medicine has been prescribed for you - a repeat prescription form or a patient information leaflet from the pack is generally considered suitable.

  • Taking clonazepam over a period of time can make you become tolerant to it. If this happens, it will not be as effective for you as it once was. If you think this is happening to you, please discuss it with your doctor.

  • Taking benzodiazepines like clonazepam can lead to the development of dependence. This means that your body becomes dependent on the medicine. If you are concerned about this, you should discuss it with your doctor.

  • Many antiepileptic medicines can harm an unborn child. If you are a woman, make sure you have discussed with your doctor which types of contraception are suitable for you and your partner. If you want to have a family, discuss this with your doctor so that you can be given advice from a specialist before you become pregnant.

  • If you are due to have an operation or any dental treatment, tell the person carrying out the treatment which medicines you are taking.

  • You need to take clonazepam regularly every day. Do not stop taking it until your doctor tells you to stop. Stopping treatment suddenly can cause problems and your doctor will want you to reduce your dose gradually when this becomes necessary.

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Can clonazepam cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the more common ones associated with clonazepam. The best place to find a full list of the side-effects which can be associated with your medicine, is from the manufacturer's printed information leaflet supplied with the medicine. Alternatively, you can find an example of a manufacturer's information leaflet in the reference section below. Speak with your doctor or pharmacist if any of the following continue or become troublesome.

Common clonazepam side-effects

What can I do if I experience this?

Feeling sleepy, weak, or light-headed (these can continue into the following day)

Do not drive and do not use tools or machines. Do not drink alcohol

Feeling unsteady, poor co-ordination, unusual eye movements, poor concentration, feeling forgetful or confused

If any of these become troublesome, discuss them with your doctor

In young children, increased amounts of saliva may lead to coughing or choking

Let your doctor know if this happens

If you experience any other symptoms which you think may be due to the medicine, speak with your doctor or pharmacist for further advice.

How to store clonazepam

  • Keep all medicines out of the reach and sight of children.

  • Store in a cool, dry place, away from direct heat and light.

  • The oral liquid medicine usually lasts for one month after first opening, but always check the expiry date on the medicine you are supplied with. It is a good idea to write the date you opened the bottle on to the label.

Important information about all medicines

Important information about all medicines

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital at once. Take the container with you, even if it is empty, so the doctor knows what has been taken.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

If you buy any medicines check with a pharmacist that they are safe to take with your other medicines.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about this medicine ask your pharmacist.

Report side effects to a medicine or vaccine

If you experience side effects, you can report them online through the Yellow Card website.

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.

  • Next review due: 26 Sept 2025
  • 27 Sept 2022 | Latest version

    Last updated by

    Michael Stewart, MRPharmS

    Peer reviewed by

    Sid Dajani
  • 27 Apr 2010 | Originally published

    Authored by:

    Helen Allen
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