Authored by , Reviewed by Sid Dajani | Last edited | Certified by The Information Standard

Swallow the capsules whole with a drink of water. Do not chew them.

Clomethiazole will make you sleepy. If you still feel sleepy the next day, do not drive and do not use tools or machines.

Do not drink alcohol whilst being treated with clomethiazole.

The most common side-effects are a runny or blocked nose, and headache. These should soon pass.

Type of medicineHypnotic and sedative
Used forInsomnia, restlessness, or agitation, particularly in elderly people
Alcohol withdrawal symptoms
Available asCapsules and oral liquid medicine

Insomnia, or poor sleep, is fairly common. If you have problems sleeping, it may mean that you have difficulty getting off to sleep, or you may wake up for long periods during the night, or you may wake up too early in the morning. 'Sleeping pills' like clomethiazole are considered a last resort, but are sometimes prescribed for a short period of time to help with a particularly bad spell of insomnia.

Clomethiazole is also prescribed in certain circumstances to help calm elderly people who are particularly restless or agitated. It is also used within specialist dependency units to relieve the symptoms of alcohol withdrawal.

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

  • If you are pregnant or breastfeeding.
  • If you have a heart condition, or liver or kidney problems.
  • If you have lung or breathing problems or a problem where you stop breathing for short periods at night (sleep apnoea).
  • If you have ever had a drug addiction or a personality disorder.
  • If you are taking 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.
  • If you have ever had an allergic reaction to a medicine.
  • Before you start this treatment, read the manufacturer's printed information leaflet from inside your pack. The leaflet will give you more information about clomethiazole and a full list of side-effects which you may experience from taking it.
  • Take clomethiazole exactly as your doctor tells you to. Your dose will be on the label of the pack to remind you:
    • If you have been prescribed clomethiazole for insomnia, your doctor may recommend that you take one or two capsules each evening, or only on certain days of the week. Take the capsules just before you go to bed.
    • If you have been prescribed clomethiazole to help calm restlessness or agitation, your doctor is likely to recommend that you take one capsule three times daily, for a short period of time.
    • If you have been prescribed clomethiazole to help reduce alcohol withdrawal symptoms, your doctor or clinic will tell you how to take it.
  • If you have been prescribed capsules, swallow them whole with a drink of water. Do not chew them.
  • If you have been prescribed the oral liquid medicine it should be diluted with water or juice and swallowed immediately. Measure the correct amount of medicine for your dose and add it to a glass. Mix well with water or juice and ensure you drink the entire contents of the glass. Do not use plastic containers to mix your medicine in.
  • If you forget to take a dose, take it as soon as you remember unless it is nearly time for your next dose, in which case skip the missed dose. Do not take two doses together to make up for a forgotten dose.
  • Try to keep your regular appointments with your doctor. This is so your doctor can check on your progress.
  • Clomethiazole will make you sleepy. If you still feel sleepy the next day, do not drive and do not use tools or machines.
  • Do not drink alcohol whilst being treated with clomethiazole.
  • Clomethiazole is only recommended for a short period of time. This is because your body can become dependent on it after a while. This can cause problems when you then stop taking it.

Along with their useful effects, all medicines can cause unwanted side-effects although not everyone experiences them. The table below lists some of the most common ones associated with clomethiazole. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve over the first few days of taking a new medicine, but speak with your doctor or pharmacist if any of the following side-effects continue or become troublesome.

Common clomethiazole side-effects
What can I do if I experience this?
HeadacheDrink plenty of water and ask your pharmacist to recommend a suitable painkiller. If the headaches continue, let your doctor know
A runny or blocked nose, sore eyesThese can occur soon after taking a dose, but usually quickly pass

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

  • Keep all medicines out of the reach and sight of children.
  • Store the capsules in a cool, dry place, away from direct heat and light.

If you buy any medicines, check with a pharmacist that they are safe to take with your other 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. Take the container with you, even if it is empty.

If you are having an operation or dental treatment, tell the person carrying out the treatment which medicines you are taking.

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

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.

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