|Main use||Active ingredient||Manufacturer|
How does it work?
Clonazepam is a type of medicine called a benzodiazepine. This type of medicine acts on nerve cells in the brain.
The brain and nerves are made up of many nerve cells that communicate with each other through electrical signals. These signals must be carefully regulated for the brain and nerves to function properly.
When abnormally rapid and repetitive electrical signals are released in the brain, it becomes over-stimulated and normal function is disturbed. This results in fits or seizures.
Clonazepam works by acting on receptors in the brain called GABA receptors. This causes the release of a neurotransmitter called GABA in the brain. GABA is involved in transmitting messages between the nerve cells and acts as a natural 'nerve-calming' agent. It helps keep the nerve activity in the brain in balance.
By increasing the release of GABA, clonazepam helps to calm the excessive electrical nerve activity that is responsible for causing seizures
Clonazepam is used to help to reduce the frequency and severity of fits in people with epilepsy.
What is it used for?
- Clonazepam is used to treat various different forms of epilepsy, including absence seizures (petit mal epilepsy), generalised tonic-clonic seizures (grand mal epilepsy), partial seizures and myoclonic seizures.
How do I take it?
- Clonazepam can be taken either with or without food.
- Your doctor will start you off on the lowest dose of clonazepam and then gradually increase your dose over a period of two to four weeks until a suitable dose for you is reached.
- To start off with you should take the prescribed daily dose in three or four divided doses. This means taking the medicine three or four times a day with approximately the same time intervals between each dose. If it is not possible to divide the daily dose into equal doses then you should take the largest dose at bedtime.
- Once your maintenance dose has been reached it will usually be possible for you to take your total daily dose as a single dose at bedtime. Follow the instructions given by your doctor or pharmacist.
- It is important to take your medication regularly, as directed by your doctor, because missing doses can trigger seizures in some people. If you have trouble remembering to take your medicine you should ask your pharmacist for advice. You may find a pill reminder box helpful.
- Do not stop taking this medication except on your doctor's advice.
- This medicine causes drowsiness and muscle weakness and impairs concentration and alertness. These effects may continue into the following day and are made worse by drinking alcohol. If you are affected you should not drive or operate machinery. Do not drink alcohol while taking this medicine.
- From March 2015 a new 'drug driving' law comes into force, which makes it an offence to drive with certain drugs or prescription medicines above specified limits in your body. The list includes clonazepam, which means it may be an offence to drive while you are taking this medicine. The new law will allow police to use roadside drug tests to check for the presence of the prohibited drugs in a driver's saliva. There are very low limits for illegal drugs, but higher limits for prescribed medicines. This should mean that most people taking clonazepam as prescribed will not be breaking the law, provided they are not driving dangerously. If you are found to be above the limit for clonazepam there is a medical defence if you are taking the medicine as prescribed, as long as your driving is not impaired. If you are taking a high dose of clonazepam it may therefore be sensible to carry your prescription with you when driving, in case you are asked to take a test by the police. However, if you are driving dangerously while taking this medicine you will be breaking the law. You should not drive if you think this medicine affects your ability to drive safely, for example if it makes you feel sleepy, dizzy, unable to concentrate or make decisions, or if you have blurred or double vision.
- You should not suddenly stop taking this medicine unless your doctor tells you otherwise, as this may result in your seizures returning or getting worse. Stopping a benzodiazepine suddenly can also cause withdrawal symptoms such as insomnia or anxiety, confusion, sweating, tremor, headache or irritability. If your doctor decides that you should stop taking this medicine, this should be done gradually. Follow the instructions given by your doctor.
- It is important to tell your doctor if you have recently suffered a loss or bereavement, for example the death of a close friend or relative, before taking this medicine. Benzodiazepines such as this one can affect the way you adjust psychologically to events like this.
- Some antiepileptic medicines have been associated with a small increased risk of suicidal thoughts and behaviour. It is not known if clonazepam also has this effect, but for this reason, it is very important to seek medical advice if you, or someone else taking this medicine, experience any changes in mood, distressing thoughts, or feelings about suicide or self-harm at any point while taking this medicine. For more information speak to your doctor or pharmacist.
Not to be used in
- Patients in a coma.
- People who are known to be abusing pharmaceuticals, drugs or alcohol.
- People with a condition involving abnormal muscle weakness (myasthenia gravis).
- People with severe breathing problems or a sudden worsening of any underlying lung disease (acute pulmonary insufficiency).
- People with a syndrome where breathing stops for short spells during sleep (sleep apnoea syndrome).
- People with severely decreased liver function.
- People who are allergic to any other medicine in the benzodiazepine family, eg diazepam, temazepam.
This medicine should not be used if you are allergic to any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.
If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.
Use with caution in
- Elderly people.
- Weak or debilitated people.
- Decreased liver function.
- Decreased kidney function.
- People with lung disease such as COPD.
- People with a long-term decrease in lung function (chronic pulmonary insufficiency).
- People with a history of alcoholism or drug abuse.
- People with a history of depression or suicidal behaviour.
- People with shaky or unsteady voluntary movements eg walking, resulting from disorders in the brain or spinal cord (spinal or cerebellar ataxia).
- People with rare inherited blood disorders called porphyrias.
Pregnancy and breastfeeding
Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.
- It is vital that women with epilepsy receive specialist advice before getting pregnant, so they are well informed of potential risks and benefits of continuing antiepileptic treatment. Pregnant women taking antiepileptic medicine have a higher risk of carrying a baby with developmental problems and malformations. However, if a woman with epilepsy stops treatment because she is pregnant, there is a risk of seizures that can harm both mother and baby. This risk may be higher than that from continuing the medication. It is important that all the risks and benefits of treatment are weighed up. Seek medical advice from your doctor.
- This medicine should be avoided during pregnancy unless considered essential by your doctor. This is particularly important during the third trimester of pregnancy and before or during labour. If this medicine is used in late pregnancy or during labour it may cause floppiness, low body temperature and breathing or feeding difficulties in the baby after birth. It may also result in withdrawal symptoms in the baby after the birth. Ask your doctor for further information.
- If you get pregnant while taking this medicine it is vital to get advice from your doctor as soon as possible. You should not suddenly stop taking this medicine because this may cause your seizures to come back, as well as withdrawal symptoms (see warning section above).
- This medicine passes into breast milk and could have harmful effects on a nursing infant. If you need to take this medicine to control your epilepsy your doctor may suggest that you bottlefeed rather than breastfeed. It is important to get medical advice from your doctor.
Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.
- Drowsiness and sleepiness.
- Concentration difficulties.
- Decreased co-ordination.
- Delayed reactions.
- Muscle weakness.
- Shaky movements and unsteady walk (ataxia).
- Loss of memory following an epileptic seizure (anterograde amnesia).
- Changes in behaviour such as aggression, anxiety, agitation, nervousness.
- Nightmares or vivid dreams.
- Difficulty with speech.
- Involuntary eye movements (nystagmus).
- Double vision.
- Skin reactions such as rash, itching, changes in pigmentation.
- Hair loss (reversible if treatment is stopped).
- Sexual problems such as loss of sex drive or erectile dysfunction.
- Urinary incontinence.
- Heart failure.
- Slow, shallow breathing (respiratory depression).
- Increased saliva or phlegm production (in infants and young children only).
- Physical and psychological dependence on the medicine can occur with benzodiazepines like this one, particularly if high doses are used for long periods of time. Withdrawal symptoms are possible if the medicine is stopped abruptly - see the warning section above.
The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.
For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.
How can this medicine affect other medicines?
It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while having treatment with this one, to make sure that the combination is safe.
There may be an increased risk of drowsiness and sedation if clonazepam is taken with any of the following (which can also cause drowsiness). These should be avoided while you are taking clonazepam:
- antipsychotics, eg chlorpromazine, clozapine
- barbiturates, eg phenobarbital
- other benzodiazepines, eg temazepam
- MAOI antidepressants, eg phenelzine
- sedating antihistamines, eg chlorphenamine
- sleeping tablets, eg zopiclone
- strong opioid painkillers, eg morphine, codeine, dihydrocodeine
- tricyclic antidepressants, eg amitriptyline.
The following medicines may prevent the breakdown of clonazepam in the body. As this could increase the blood level of clonazepam and its sedative effects, as well as the risk of its side effects, your doctor may need to prescribe you a lower than normal dose of clonazepam if you are taking any of these medicines:
- protease inhibitors for HIV infection, such as ritonavir or fosamprenavir.
The following medicines may decrease the blood level of clonazepam. As this could make it less effective, your doctor may need to prescribe you a larger than normal dose of clonazepam if you are taking any of these medicines:
- sodium valproate.
There may be an increased risk of side effects if this medicine is taken in combination with lithium.
Other medicines containing the same active ingredient
Clonazepam tablets used to be available under the brand name Rivotril, however these have now been discontinued. Clonazepam tablets and oral solution are now only available without a brand name, ie as the generic medicine.
Care should be taken if switching between clonazepam tablets and oral solution, or between generic clonazepam products made by different manufacturers. This is because clonazepam in different forms or made by different manufacturers may potentially differ in the way it is absorbed into the body, which could either reduce the effect of the medicine and increase the risk of seizures, or increase the effect of the medicine and increase the risk of side effects. You should check with your pharmacist if you are ever dispensed your clonazepam in a different form or made by a different manufacturer.