Pennine Care NHS Foundation Trust
225 Old Street, Ashton-under-Lyne, OL6 7SR

Medicines Information Service

Condition: Alcohol withdrawal

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  • What is alcohol withdrawal?

    Alcohol withdrawal (or Alcohol Withdrawal Syndrome; AWS) is the group of symptoms that someone will get if they have been drinking enough for long enough, and then stop suddenly.

    Alcohol drinking problems can be put into 3 groups:

    1. Hazardous drinking

    • The official sensible adult weekly limits are 21 units for men and 14 units for women (see next question)

    • Hazardous drinking is where someone is drinking above the "sensible limits" but has no major alcohol-related problems

    • This can include binge drinking, where someone stays within the weekly limit but has it all in one day e.g. more than 8 units in a day for men or 6 units a day for women

    2. Harmful drinking

    • Someone is drinking above the sensible weekly limits (as above) and has some alcohol-related problems e.g. dependence and can get withdrawal symptoms sometimes, but these may only be mild.

    3. Alcohol dependence (alcoholism)

    • This is where someone is drinking and has the same symptoms as other dependences:

    •  Continual desire to drink 

    •  Return to drinking after abstinence, even with a single drink

    •  Severe withdrawal symptoms

    •  Continued drinking despite knowing of the harm it is causing

    Alcohol withdrawal usually happens with people who have been "harmful drinking" or are "Alcohol dependent". The official sensible adult weekly limits are 21u for men and 14u for women (see next question) but you would probably need to drink more than this to get major alcohol withdrawal symptoms.

    Updated 9.13

  • What are the sensible limits of alcohol drinking?

    You can work out someone's alcohol intake using the NHS on-line alcohol unit calculator. If you don't want to use this see the advice below.  

    How much alcohol you can safely drink will depend on your age, sex and state of health. The official UK limits are as follows:

    Men age 18-65 = 3-4 units per day with at least 2-3 alcohol free days per week. No more than 21 units per week.

    Women aged 18-65 = 2-3 units per day with at least 2-3 alcohol free days per week. No more than 14 units per week.

    If you are either younger or older than 18-65 yrs of age or if you have significant health problems (particularly affecting the liver or heart) you should drink less than these limits.

    If you are pregnant the British Medical Association recommends stopping drinking altogether. Alcohol is the commonest cause of preventable brain damage in babies.

    It is now clear that 4 or more units of alcohol a day for men and 3 or more units a day for women carries a cumulative risk of harm i.e. the longer you drink above these levels, the more damage you cause.   

    One unit of alcohol in UK contains 8g of pure alcohol [NB beware as the "one unit" contains more alcohol in Australia and USA). There is around one UK unit of alcohol in the following:

    • Half pint of standard beer, lager or cider
    • Small pub measure of spirits (25ml)
    • Standard pub measure of fortified wine e.g. sherry (50ml)

    Some UK examples include:

    • Pub measure of spirits = 1.5 units
    • Standard pub measure of wine (125ml) = 1.5 units
    • Can of standard beer or lager = 2 units
    • Can of strong beer or lager = 3 units
    • Pint of standard lager, beer or bitter = 2.3 units
    • Pint of strong lager, beer or bitter = 2.8 units
    • Small glass of wine = 1.5 units
    • Large glass of wine = 3 units
    • Alcopops = 1.4 units
    • Glass of spirits (25ml) = 1 units
    • Bottle of wine = 9-10 units
    • 1L bottle of standard cider = 4 units
    • 1L bottle of strong cider = 9 units
    • Bottle spirits (700ml) = 27-28 units

    To work out the number of units of alcohol in a drink:

    • Write down the "volume of alcohol" (i.e. alcohol content) as stated on the bottle, can or label (e.g. wine is usually around 8-10%, beer 3-4%)
    • Work out how many millilitres (ml) you have drunk (a pint is 568mls, a can of Coke is 330ml, a larger can is usually 440ml or 500ml)
    • Multiply the two together and divide by 1000

    Alcohol content in % x mls    = units of alcohol

    Example 1:

    An ordinary beer at 3.5% alcohol:  
    A pint of it would be 568ml
    3.5 x 568 = 1988
    1988 divided by 1000 = 2 units (or 1.988 units to be exact)

    Example 2:

    A strong cider at 6% alcohol:
    A large can of it would be 500ml
    6 x 500 = 3000
    3000 divided by 1000 = 3 units

    Example 3:

    A Smirnoff Ice at 4% alcohol:
    A bottle would be 275ml
    4 x 275 = 1100
    1100 divided by 1000 = 1.1 units

    A report in June 2011 from the Royal College of Psychiatrists (published in the British Medical Journal 2011;342:d3950) has suggested lower safe drinking limits for people aged over 65 years. The report recommends up to 1.5 units a day for men and 1 unit a day for women. "Binge drinking" is set at 4.5 units or more in men and 3 units or more in women in a single session. The report, called ‘Our Invisible Addicts’, says that the changes from aging (e.g. changes to the body with age and how the liver breaks down alcohol) mean that the current safe limits are too high for elderly people. You can read the report by clicking here.

    It is also recommended to have 2 drink-free days a week, because if you can't have at least one drink-free day a week then you do have a problem.

    Updated 9.13

  • What are the symptoms of alcohol withdrawal?

    To get alcohol withdrawal symptoms, you have to have been drinking quite a lot for quite a while first e.g. more than 12-16 units a day. For less than this, gradual reduction in alcohol over several days or weeks can usually be done with care.

    Alcohol Withdrawal Symptoms (AWS) after stopping alcohol suddenly can include:

    • Anxiety

    • Tremor

    • Nausea and vomiting

    • Disorientation (not knowing where you are)

    • Hallucinations (seeing or hearing things that aren't there)

    • Tachycardia (fast heart rate)

    • Sweating and fever

    • Fits or seizures, which can start as quickly as 6hrs to 8hrs after the last drink, can last 5-7 days, and can be fatal

    If someone stops suddenly, about 1 in 10 (10%) get delirium tremens (DTs), especially if they have been drinking a large amount. The symptoms of DTs are the same as above, plus:

    • Agitation

    • Confusion

    • Paranoia and hallucinations (seeing and hearing things that aren't there, thinking that things are happening that aren't)

    • Seizures or fits (often within 6-8hrs of stopping drinking)

    • Shaking

    • High body temperature

    • Shock

    • Pneumonia and other infections

    • suicidal ideation

    • gross disorientation

    • violence

    • marked tremor

    Around 1 in 10 people who get DTs die if it is not treated.

    Alcohol withdrawal has to be treated carefully to minimise major problems, because it can be fatal or at least very, very unpleasant. If someone has been drinking a lot, stops suddenly and starts to get hallucinations or fits, it should be treated in hospital.

    In the first 2 days, loss of thiamine can lead to something called Wernicke's encephalopathy. If untreated it can lead on to the chronic form (Korsakoff psychosis, KP) characterised by severe short-term memory loss. This can be so bad that the person "confabulates" i.e. makes things up to cover for a lack of memory. These stories can be highly believable, but when asked the same question an hour later, a completely difference answer will be given.

    Updated 12.13

  • Does anything else have the same symptoms as alcohol withdrawal?

    Sudden confusion and generalised illness can have many causes other than alcohol withdrawal (or be made worse by these):

    • Sleep deprivation

    • Disorientation, especially in older people moved into an unfamiliar environment

    • Drugs e.g. sedatives, pain killers, steroids, atropine, cimetidine, digoxin

    • Infections e.g. chest, urinary tract, at the site of an operation

    • Blood disturbances e.g. low sodium, low phosphate, high calcium

    • Physical problems e.g. tumour in the brain, seizures

    • Low blood pressure

    • Organ failure e.g. kidney problems, heart failure,

    • Hormone problems e.g. diabetes, low or high thyroid

    Of course, if it is known that the person has been drinking heavily and has suddenly stopped, the diagnosis is a bit easier to make.

    Updated 8.13

  • What are the causes alcohol withdrawal ?

    To get alcohol withdrawal symptoms, firstly you have to have been drinking quite a lot for quite a while e.g. more than about 12 units a day. For less than this, gradual reduction in alcohol over several days or weeks can usually be done with care.

    Alcohol has many effects on the brain. One of these is to increase the amount of GABA in the brain. GABA is the main calming chemical messengers (transmitter) in the brain. Alcohol also reduces the amount of glutamate, which is the main excitatory chemical messenger in the brain. If you stop alcohol suddenly, then you can get less GABA and more glutamate. This means the brain becomes over excited (or less calm) and so this is how fits or seizures can happen e.g. there is nothing to stop random messages being passed around the brain. The only way to get this in balance again is to drink more alcohol. And so it goes on.  

    Updated 8.13

  • What are the main alternatives for helping treat alcohol withdrawal?

    The lists here include most of the main options for alcohol withdrawal but does not say what works and doesn't. Many may be used in combination. Our aim is to try to help people who are taking medication (or should be) get the right medicine, dose and take it regularly for as long as is right. Any medicines should usually be part of the overall treatment, although some people are quite happy just to stick with drugs or talking treatments. If your medicines are right, then everything else can fall into place. If the medicines are wrong, then they may make the symptoms worse and self-help will not be as useful.


    • Taking any medicines regularly and reliably

    • Plan for the withdrawal symptoms e.g. plan activities to relieve boredom, drink enough liquid not to get dehydrated, eat properly

    • Planning for the long-term consequences of stopping alcohol and staying stopped

    Help from others

    • Helping you be ready for stopping drinking e.g. plan activities to relieve boredom, make sure you drink enough liquid, and eat normally,

    • Preparing you for the withdrawal symptoms e.g. planning activities to relieve boredom, drinking enough liquid so you do not get dehydrated, making sure you eat properly


    There are some medicines to help reduce the risk of alcohol withdrawal. Another group of medicines can help you keep off or manage your alcohol intake.

    Updated 9.13

  • What are the main medicine treatments for alcohol withdrawal?

    If you are prescribed a medicine, then there may be many reasons why that one has been chosen. These might include:

    • side effects (which ones are important to you)
    • local policies or agreements (such as what that GP surgery uses, in your area etc)
    • national policies (e.g. NICE, SIGN - see last question)
    • familiarity (it may be better to get best out of a medicine you are familiar with)
    • relative costs for similar medicines
    • personal preference (either yours or your prescriber)
    • how bad your symptoms are
    • any medicine you might have done well with in the past (as it's more likely to work again)

    For convenience, the "Main medicines” are those medicines that are officially "approved" to treat the condition or symptoms. They are listed in the British National Formulary ( To be listed in the BNF there needs to be good evidence that the medicine works and that the producers have applied for a license (a long and costly exercise). "Others" are those medicines where there is some evidence that they help, but either not enough for a license or that no license has been applied for. These should usually only be used where other standard treatments have failed.

    Alcohol Withdrawal Syndrome can be life-threatening so it must be taken very seriously. If someone has been drinking higher amounts, it is usually a very good idea to go into hospital for a "detox" (detoxification), especially if the symptoms might be severe, there is a history of fits or seizures, Wernicke's Encephalopathy is possible or if there are physical or psychological problems.   

    Main medicines:

    BNF Listed
    • Benzodiazepines - there is a degree of "cross tolerance" with alcohol and so these will help stop fits or seizures. The dose usually depends on your symptoms e.g. blood pressure, pulse, agitation, and delirium (confusion). They usually start with a high loading dose (which depends on how bad the withdrawal symptoms are or might be), then reduced

      • Chlordiazepoxide - to help stop withdrawal seizures or fits, usually a 7 day course of reducing doses, slower onset but less chance of abuse   

      • Diazepam - to help stop withdrawal seizures or fits, and has a slightly quicker onset

      • Lorazepam or oxazepam if there are liver problems

    • Clomethiazole (Heminevrin®) - to help stop withdrawal seizures or fits. But has a higher risk of dependence, is really very toxic if you overdose (and that's not difficult to do) and can build up in the body if your liver is damaged. So although it is licensed, these problems mean it is rarely used as better medicines e.g. the benzodiazepines or some of the anticonvulsants, are much better and safer.

    • Pabrinex ® - to give a rapid boost to dangerously low vitamin levels, which may drop even quicker or further during withdrawal or a detox

    • Thiamine - to help a lack of the essential vitamin thiamine

    • Vitamin B & C strong - to help a lack of thiamine and other vitamins


    • Hypnotics, if needed to help sleep

    • Baclofen - used in some areas

    • Carbamazepine (Tegretol®) - to help stop withdrawal seizures or fits - it is not used routinely, and less likely to be successful in the long-term but can be useful sometimes

    • Antipsychotics - if the person has lots of hallucinations or psychosis but can make fits more likely

    Sometimes the symptoms caused by a lack of vitamins can be so severe that the person looks like they are intoxicated or drunk.

    Updated 12.13

  • Is there an easy way to compare the main medicines for alcohol withdrawal?

    Download a handy summary chart comparing the main medications for alcohol withdrawal e.g. names, how they work, doses, how long they take to work, some side effects, how long to take and how to stop.

    Updated 8.11

  • What might happen if I don't have any treatment for alcohol withdrawal?

    See "what are the symptoms of alcohol withdrawal" for a list of symptoms. Without treatment, these symptoms will get worse, depending on how much you have been drinking. Heavy sedation may be needed, and you can get pneumonia. Death is quite possible, either from seizures (epileptic fits), bleeds, or infections.  

    Updated 12.13

  • If the medication is helping alcohol withdrawal symptoms, how long will I need to keep taking it?

    Usually to help with Alcohol Withdrawal Syndrome, no more than 7-10 days or so treatment is needed to help stop fits or seizures. Thiamine and other vitamins may be needed for a few months to build up your body's reserves.

    Updated 12.13

  • How long will the medicine take to work for alcohol withdrawal?

    Your medical team will help you with this. The medicines will usually have an effect within an hour or so.

    Reviewed 9.13

  • How many medicines should I be taking for my alcohol withdrawal?

    Usually, there are no easy answers to this and it is a very individual choice. Generally one medicine should always be the aim but combinations (often called "polypharmacy") sometimes help. It is rarely of any use to combine drugs with similar ways of working. Below are some of the combinations that are used with the reasons. This is not a complete list but you might want to talk to your prescriber about any combinations not on this list you may be prescribed.

    Main medicine

    Second medicine



    Anything else

    Essential to replace thiamine



    To prevent Wernicke's encephalopathy


    Anything else 

    To help stop seizures or fits

    Updated 8.13

  • Are there any guidelines available for managing alcohol withdrawal?

    If you want to read up a bit more on the best treatments, there are many guidelines that you can look at. Probably the most important of these for England and Wales are those produced by NICE. NICE is the National Institute for Health and Clinical Excellence. NICE is an independent body that is asked to produce advice about preventing and treating illnesses and promoting good health. Scotland and Northern Ireland have their own similar bodies.

    Each set of NICE Guidelines is written by an independent and carefully chosen group of specialists and experts (including service users and carers). They carefully review the available evidence and base their guidelines on this.

    There are two main types of guidance:

    • "Technology appraisal". These look at an "intervention" (i.e. a medicine, a surgical operation etc) and decide if they think the evidence is good enough to make this intervention a standard and/or if it is cost-effective compared to other treatments

    • "Clinical guidelines", which look at a particular condition (e.g. hypertension, lung cancer, depression, Parkinson's disease, bipolar disorder etc) and give guidelines covering medicines, services, support etc.

    The guidelines are well intentioned and give generally sound (although sometimes controversial) guidance. They are, however, only "guidelines", so are not rigid instructions.
    When NICE issues a guideline, it produces a full set, and all of these are available on the NICE website: 

    • Full guidelines (very long and detailed, often several hundred pages, for anorak healthcare professionals only)

    • Official guideline (the summary version for healthcare professionals)

    • Quick reference guideline for healthcare professionals

    • User-friendly summary for service users, carers and the general public

    These are then reviewed every few years.

    As a general rule, you should start with treatments recommended by NICE as these are the ones with most evidence that they work. However, if these do not help you, it may be useful to try other treatments. AT the moment NICE or SIGN do not have any guidelines on alcohol withdrawal, but have some on alcohol dependence:

    As a general rule, you should start with treatments recommended by NICE as these are the ones with most evidence that they work. However, if these do not help you, it may be useful to try other treatments.

    There are plenty of other guidelines and so-called "consensus statements" (where a group of experts and specialists pool their ideas, based more on their own experiences and what the published papers say rather than just what the published studies say). These will have been produced for healthcare professionals by such bodies as BAP (British Association for Psychopharmacology) in 2012.

    Updated 9.13

  • Where else can I go for advice for alcohol dependence?

    Use the resources below to find out more information about alcohol dependence. Please note that this is not an exhaustive list. We welcome your feedback on resources that you think should be listed here., a really useful site from the Northern Ireland Public Health Agency

    Mental Health Ireland has a great links page on this extensive site

    Your Mental Health Ireland, with a young person’s page as well

    Information about local mental health trusts is available on the NHS Choices website.

    The British Association for Psychopharmacology has a BAP public area, which has loads of interesting articles, some mentioning alcohol dependence.

    The Big White Wall is a 16+ safe, anonymous web-based service for people experiencing emotional or psychological distress provided entirely online. Professionally staffed 24/7 it offers a wide range of services for improving mental wellbeing including tests, peer support, individual and group therapies, articles, tips and creative self expression. Simply click on the link to learn more, or to join for £2.00 a week.

    Updated 3.13

Glossary terms


BNF stands for the British National Formulary (BNF). The BNF provides information on the pharmacology, side effects and costs of the prescription of all medications available on the National Health Service.

Find out more

The Pennine Care NHS Foundation Trust clinical pharmacy services exist to proactively support staff, patients and carers with safe and effective medicines management and optimising the use of medicines by providing a high quality and professional service.

We do this by providing:

We have specialist pharmacists and technicians working across the Trust in Bury, Oldham, Rochdale, Stockport and Tameside.

Pharmacy contact details:

Lesley Smith, Chief Pharmacist
Trust Headquarters
225 Old Street

Services are provided 9am - 5pm, Monday to Friday and staff, patients and carers have access to specialist pharmacists and technicians during these hours.

Staff have access to ‘on call’ pharmacy services outside of these hours

Medicines Information Service
Tel: 0161 716 3378