Chlordiazepoxide (Librium)

How does it work?

Librium capsules contain the active ingredient chlordiazepoxide, which is a type of medicine called a benzodiazepine. (NB. Chlordiazepoxide is also available without a brand name, ie as the generic medicine.)Benzodiazepines are used for their sedative, anxiety-relieving and muscle-relaxing effects.

Chlordiazepoxide works by acting on receptors in the brain called GABA receptors. This causes the release of a neurotransmitter called GABA in the brain.

Neurotransmitters are chemicals that are stored in nerve cells in the brain and nervous system. They are involved in transmitting messages between the nerve cells. GABA is a neurotransmitter that acts as a natural 'nerve-calming' agent. It helps keep the nerve activity in the brain in balance, and is involved in inducing sleepiness, reducing anxiety and relaxing muscles.

As chlordiazepoxide increases the activity of GABA in the brain, it increases its calming effect and results in sleepiness, a decrease in anxiety and relaxation of muscles.

Chlordiazepoxide is used for the short-term treatment of severe anxiety, including anxiety associated with insomnia. Chlordiazepoxide decreases the time taken to fall asleep and nocturnal awakenings, as well as increasing the total amount of time spent sleeping. However, it is only suitable for short-term treatment of anxiety and insomnia as it has a high potential for dependence and addiction. As chlordiazepoxide remains active in the body for many hours, drowsiness may also last into the next day.

Chlordiazepoxide is used in the treatment of alcoholism for its sedating and anxiety-relieving effects, which help relieve the symptoms of acute alcohol withdrawal.

A further use is in controlling muscle spasms.

What is it used for?

  • Short-term (two to four weeks only) treatment of severe anxiety and associated insomnia that is disabling or subjecting the individual to unacceptable distress.
  • Managing symptoms of withdrawal from alcohol (used in combination with other treatment for alcoholism).
  • Controlling muscle spasms.

Warning!

  • 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 avoid potentially hazardous tasks such as driving or operating machinary. Avoid alcohol.
  • This medicine is generally only suitable for short-term use. If it is used for long periods or in high doses, tolerance to and dependence upon the medicine may develop, and withdrawal symptoms may occur if treatment is stopped suddenly.
  • Treatment with this medicine should usually be stopped gradually, following the instructions given by your doctor, in order to avoid withdrawal symptoms such as rebound insomnia or anxiety, confusion, sweating, tremor, loss of appetite, irritability or convulsions.

Use with caution in

  • Elderly people.
  • Weak or debilitated people.
  • Decreased kidney function.
  • Decreased liver function.
  • Disease affecting the airways or lungs (respiratory disease).
  • Abnormal muscle weakness (myasthenia gravis).
  • History of alcoholism or drug abuse.
  • Personality disorders.
  • Depression.
  • 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.

Not to be used in

  • Children.
  • Allergy to benzodiazepines.
  • A sudden worsening of any underlying lung disease (acute pulmonary insufficiency).
  • Slow, shallow breathing (respiratory depression).
  • Syndrome involving short spells when breathing stops during sleep (sleep apnoea syndrome).
  • Long-term psychotic illness.
  • Phobias or obsessional states.
  • Severely decreased liver function.
  • Breastfeeding.

This medicine should not be used if you are allergic to one or 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.

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.

  • This medicine may be harmful to a developing baby and it should be avoided during pregnancy unless considered essential by your doctor. This is particularly important during the first and third trimesters of pregnancy and before or during labour. Regular use during pregnancy should especially be avoided, as the baby could become dependent on the medicine and then suffer withdrawal symptoms after the birth. 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. Ask your doctor for further information.
  • Significant amounts of this medicine may pass into breast milk. It should not be used by breastfeeding mothers as it may be harmful to the nursing infant. Seek medical advice from your doctor.

Label warnings

  • This medication causes drowsiness which may continue the next day. If affected do not drive or operate machinery. Avoid alcoholic drink.

Side effects

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 does not mean that all people using this medicine will experience that or any side effect.

  • Drowsiness.
  • Drowsiness and lightheadedness the next day.
  • Confusion.
  • Shaky movements and unsteady walk (ataxia).
  • Loss of memory (amnesia).
  • Unexpected increase in aggression (paradoxical aggression).
  • Muscle weakness.
  • Dizziness.
  • Headache.
  • Skin rashes.
  • Disturbances of the gut such as diarrhoea, constipation, nausea, vomiting or abdominal pain.
  • Difficulty in passing urine (urinary retention).
  • Visual disturbances such as blurred vision.
  • Changes in sex drive.
  • Low blood pressure (hypotension).
  • Blood disorders.
  • Jaundice.

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 taking this one, to make sure that the combination is safe.

There may be an increased risk of drowsiness and sedation if chlordiazepoxide is taken with any of the following (which can also cause drowsiness):

  • alcohol
  • 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 chlordiazepoxide in the body. As this could increase the blood level of chlordiazepoxide 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 chlordiazepoxide if you are taking any of these medicines:

  • cimetidine
  • disulfiram.

Rifampicin may increase the breakdown of chlordiazepoxide in the body. As this could decrease the blood level of chlordiazepoxide and make it less effective, your doctor may need to prescribe you a larger than normal dose of chlordiazepoxide if you are taking this antibiotic.

Caffeine and theophylline may reduce the sedative and anxiety-reducing effects of chlordiazepoxide.

Chlordiazepoxide may reduce the effectiveness of levodopa in treating Parkinson's disease.

Chlordiazepoxide may increase blood levels of the anticonvulsant medicine phenytoin.

Other medicines containing the same active ingredient

Chlordiazepoxide capsules and tablets are also available without a brand name, ie as the generic medicine.