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Nalmefene tablets


Nalmefene will help you to reduce the amount of alcohol you drink.

Take one tablet each day that you anticipate drinking alcohol. Where possible, take the tablet 1-2 hours before having any alcohol.

Remember to keep your appointments with your doctor so that your progress can be monitored.

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About nalmefene tablets

Type of medicine

Medicine used for alcohol dependence

Used for

To reduce alcohol consumption

Also called


Available as


If you are alcohol-dependent, your body becomes used to lots of alcohol, and you experience withdrawal effects if you do not drink. This means that even if you want to reduce your drinking, it is often difficult.

Nalmefene will help you to reduce the amount of alcohol you drink if you are not able to do this on your own. It does this by interfering with the processes in your brain which are responsible for your urge to drink.

Before taking nalmefene

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 nalmefene tablets it is important that your doctor knows:

  • If you are under 18 years of age.

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

  • If you have ever had a mental health problem.

  • If you have ever had a fit (seizure).

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

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

  • 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. In particular, make sure you tell your doctor if you are taking any strong painkillers.

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How to take nalmefene tablets

  • Before you start this treatment, read the manufacturer's printed information leaflet from inside your pack. The manufacturer's leaflet will give you more information about nalmefene tablets. It will also provide a full list of the side-effects which you may experience from taking them.

  • Take nalmefene tablets exactly as your doctor tells you to. Take one tablet a day on each day that you anticipate drinking alcohol. The tablet is best taken 1-2 hours before you drink alcohol, but if you are not able to do this, take it as soon as you can.

  • Do not take more than one tablet per day.

  • Swallow the tablet whole with a drink of water - do not crush or break the tablet. You can take nalmefene before or after food.

Getting the most from your treatment

  • Keep your regular appointments with your doctor and/or counsellor. This is so your progress can be checked on a regular basis.

  • It may help to tell your family and friends how important it is that you reduce your drinking, so that they can be a support to you. Drinking heavily is a serious health risk.

  • Counselling and other support services are available to help you to reduce your drinking. Your doctor, practice nurse, or local alcohol unit will be able to advise you on what support and self-help groups are available in your area.

  • If you buy any medicines, check with your doctor or a pharmacist that they are suitable for you to take. This is because strong painkillers (some of which can be bought 'over the counter' in a pharmacy) should not be taken with nalmefene tablets.

  • If you are due to have an operation or dental treatment, tell the person carrying out the treatment that you are taking nalmefene. You may be advised to stop taking the tablets for a short while because they could affect your treatment.

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Can nalmefene tablets 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 most common ones associated with nalmefene tablets. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.

Very common nalmefene side-effects - these may affect more than 1 in 10 people taking this medicine

What can I do if I experience this?

Feeling sick (nausea)

Stick to simple meals - avoid rich or spicy foods. Try taking the tablet with a snack, such as a plain biscuit


Drink plenty of water to replace any lost fluids. If it continues, let your doctor know

Feeling dizzy or sleepy, blurred vision

Do not drive and do not use tools or machines until you feel better


Drink plenty of water and ask your pharmacist to prescribe a suitable painkiller (but remember to mention that you are taking nalmefene). If the headaches continue, let your doctor know

Sleeping problems

If troublesome, speak with your doctor

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

How to store nalmefene tablets

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

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

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. Take the container with you, even if it is empty.

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.

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.

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