Alcohol Use Disorder

Alcohol Use Disorder (AUD) is a substance use disorder characterized by repeated use of alcohol despite significant problems associated with its use. Like with all substance use disorders, there is a complex interplay between biological, social, psychological, and cultural factors.

Alcohol use is a leading risk factor for premature death and disability worldwide. It remains the leading cause of mortality for people aged 15-49 years old worldwide. In the elderly, cancers are the leading cause of alcohol-related death. Alcohol plays a significant role in the progression of cardiovascular diseases, cancer, diabetes, respiratory infections, unintentional, and intentional injuries (suicide).[1] No level of alcohol consumption improves health.[2]

Standard Drink

Quantifying alcohol use can be hard, given the wide range of alcoholic beverages, shapes, and sizes. A standard drink (SD) is a unit that is used to quantify alcohol intake in a systematic way (however, a standard drink varies from country to country). In Canada, a standard drink is any drink that contains 13.6 grams of pure alcohol or the equivalent of 0.6 ounces of 100% alcohol.

Different alcoholic beverages have different concentrations of alcohol. For example, most beers contain 5% alcohol; wines contain 12 to 13% alcohol; and spirits can contain 40% alcohol or more. In addition, different shapes and sizes of containers will contain different volume of alcoholic drinks (See figure 1).

Standard Drink Sizes (Adapted from: The Chief Public Health Officer's Report on the State of Public Health in Canada, 2014: Public Health in the Future Fig. 1

Criterion A

A problematic pattern of alcohol use leading to clinically significant impairment or distress, as manifested by at least 2 of the following, occurring within a 12-month period:

  1. Alcohol is often taken in larger amounts or over a longer period than was intended
  2. There is a persistent desire or unsuccessful efforts to cut down or control alcohol use
  3. A great deal of time is spent in activities necessary to obtain alcohol, use alcohol, or recover from its effects
  4. Craving, or a strong desire or urge to use alcohol
  5. Recurrent alcohol use resulting in a failure to fulfill major role obligations at work, school, or home
  6. Continued alcohol use despite having persistent or recurrent social or interpersonal problems caused or exacerbated by the effects of alcohol
  7. Important social, occupational, or recreational activities are given up or reduced because of alcohol use
  8. Recurrent alcohol use in situations in which it is physically hazardous
  9. Alcohol use is continued despite knowledge of having a persistent or recurrent physical or psychological problem that is likely to have been caused or exacerbated by alcohol
  10. Tolerance, as defined by either of the following:
    • A. A need for markedly increased amounts of alcohol to achieve intoxication or desired effect, or
    • B. A markedly diminished effect with continued use of the same amount of alcohol.
  11. Withdrawal, as manifested by either of the following:
    • A. The characteristic withdrawal syndrome for alcohol (refer to Criteria A and B of the criteria set for alcohol withdrawal), or
    • B. Alcohol (or a closely related substance, such as a benzodiazepine) is taken to relieve or avoid withdrawal symptoms.

Severity Specifiers

Specify if:

  • Mild: 2-3 symptoms/criteria met
  • Moderate: 4-5 symptoms/criteria met
  • Severe: 6+ symptoms/criteria met

Remission Specifiers

Specify if:

  • In early remission: After full criteria for alcohol use disorder were previously met, none of the criteria for alcohol use disorder have been met for at least 3 months but for less than 12 months (with the exception that Criterion A4, “Craving, or a strong desire or urge to use alcohol,” may be met).
  • In sustained remission: After full criteria for alcohol use disorder were previously met, none of the criteria for alcohol use disorder have been met at any time during a period of 12 months or longer (with the exception that Criterion A4, “Craving, or a strong desire or urge to use alcohol,” may be met).
  • In a controlled environment: This additional specifier is used if the individual is in an environment where access to alcohol is restricted.


The mnemonic WILD and ADDICCTeD can be used to remember the criteria for alcohol use disorder.

  • W - Work, school, home obligations failure
  • I - InterpersonaL or social consequences
  • D - Dangerous use


  • A - Activities given up or reduced
  • D - Dependence (tolerance)
  • D - Dependence (withdrawal)
  • I - Internal consequences (physical or psychological)
  • C - Can't cut down or control use
  • C - Cravings
  • T - Time-consuming use
  • e
  • D - Duration or amount is greater than intended

Important questions to ask on alcohol use history include:

  • Frequency
    • Age of first drink
    • Age of first problematic drinking (“When did it start having an impact on your function?”)
    • How often do you drink any alcohol? (“Every day? Once a month?”)
    • Longest period of abstinence (“Longest period of time where you did not use alcohol?”)
    • Time of last drink (to assess for the presence of withdrawal symptoms)
  • Triggers
    • Location (e.g. - in a bar/parties/home?)
    • Symptoms (depression/anxiety)
  • Quantity
    • What do you usually drink? (wine? beer? spirits?)
    • How much do you drink? (How much will you drink at a time?)
    • How much do you usually spend on alcohol in a week?
    • Binge drinking?
  • Treatment
    • Medications
    • Inpatient/outpatient treatment
  • Goals
    • “What would you like to see happen with your drinking?” (e.g. - complete abstinence, harm reduction)

Type A vs. Type B Alcohol Use

Historically, different phenotypes of alcohol use can predict response to medications and treatment. Alcohol use has been classically divided into:[3]
  • Type A alcoholism = later age of alcohol use disorder, less family history (i.e. - fewer first degree relatives with alcohol use disorder), less severe dependence, fewer co-morbid psychiatric disorder and symptoms, and less psychosocial impairment
  • Type B alcoholism = more severe alcohol use disorder, characterized by earlier age of onset, a strong family history, childhood conduct and behavioural problems, polysubstance abuse, more co-morbid psychiatric disorders (in particular anti-social personality disorder)

Type A alcoholism individuals typically respond better to sertraline, compared to Type B who have no improvement.[4]

Throughout Canada and the United States, the maximum legal blood alcohol concentration (BAC) for drivers is 80 mg of alcohol in 100 mL of blood, or a BAC of 0.08. Driving with BAC over 0.08 is a criminal offence in most jurisdictions.

Blood alcohol level and associated symptoms

Blood alcohol concentration (%) Serum blood (mg/dL) Serum blood (mmol/L) Symptoms
0.01-0.04 10-40 2-9 No loss of coordination, slight euphoria, loss of shyness
0.04-0.06 40-60 9-13 Well-being feeling, relaxation, lower inhibitions, minor impairment of reasoning and memory, euphoria
0.07-0.09 70-90 15-20 Slight impairment of balance, speech, vision, reaction time, and hearing, euphoria. Judgment and self-control reduced. Caution, reasoning, and memory are impaired.
0.10-0.13 100-125 22-27 Significant impairment of motor coordination and loss of good judgment. Speech may be slurred; balance, vision, reaction time and hearing will be impaired. Euphoria.
0.13-0.15 130-150 28-32 Gross motor impairment and lack of physical control. Blurred vision and major loss of balance. Euphoria is reduced and dysphoria is beginning to appear.
0.16-0.20 160-200 35-43 Dysphoria (anxiety, restlessness) predominates, nausea may appear. The drinker has the appearance of a “sloppy drunk.”
0.25 250 54 Needs assistance in walking; total mental confusion. Dysphoria with nausea and some vomiting.
0.30 300 65 Loss of consciousness
>0.40 400 87 Onset of coma, possible death due to respiratory depression/arrest.

How Do I Convert between BAC, mmol/L, and g/dL?

  • 1 mmol of ethanol per 1 L of blood is equal to 4.61 mg of ethanol per 100 mL (i.e. - 100mg/dL, per decilitre, or one tenth of a litre) of blood.
  • 100 mg/dL is equivalent to 0.10 (g/dL) BAC, or 0.10%. i.e. — divide by 1000 to get the BAC
  • To convert from BAC to mmol/L, ([BAC]*1000)/4.61 = mmol/L

Factors That Affect Alcohol Levels

Numerous factors can affect the blood alcohol concentration, including:
  • Age (BAC increases with age)
  • Gender (BAC is usually higher in women due to lower water content in their bodies)
  • The rate of consumption
  • Drink strength
  • Body size (smaller weight equals higher BAC)
  • Fat/muscle content (BAC is higher in those with higher percent body fat, and lower in those with more muscle mass)
  • Metabolism
  • Medication interactions
  • Food (drinking on an empty stomach will lead to higher BAC)

Alcohol and Diabetes

In patients with diabetes, alcohol ingestion can cause hypoglycaemia, particularly in Type I Diabetes, and Type II diabetics who use insulin.

Alcohol elimination follows zero order kinetics. In non-tolerant adults, the elimination is an average of 3.26 to 4.35 mmol/L/h, in tolerant adults, it is 6.5 to 8.7 mmol/L/h.[5]

Alcohol Withdrawal Tools and Scales

Name Rater Description Download
CAGE Patient The CAGE Questionnaire is an acronym formed from the 4 questions on the questionnaire (Cutting down, Annoyed, Guilty, Eye opener). The CAGE is a simple screening questionnaire for alcohol use disorder. Two “yes” is a positive screen for males; one “yes” is a positive for females. Download
AUDIT Patient The Alcohol Use Disorders Identification Test (AUDIT) is a 10-item self-report questionnaire. It asks questions about past-year quantity and frequency of drinking, consequences of drinking (e.g., blackouts), and questions similar to the CAGE. It may be more accurate than the CAGE in identifying alcohol use disorders. Also, unlike the CAGE, it can help distinguish alcohol dependence from hazardous or at-risk drinking. Download
CIWA-Ar Clinician The CIWA–Ar (revised) measures 10 symptoms. Scores of less than 8 to 10 indicate minimal to mild withdrawal. Scores of 8 to 15 indicate moderate withdrawal (marked autonomic arousal); and scores of 15 or more indicate severe withdrawal. It takes approximately 2 minutes to perform. Download
PAWSS Clinician The PAWSS is the first validated tool for the prediction of severe alcohol withdrawal syndrome in the medically ill and its use may aid in the early identification of patients at risk for complicated withdrawal, allowing for prophylaxis before severe alcohol withdrawal syndromes occur. Download

Alcohol and benzodiazepine withdrawal are treated the same way. Alcohol and benzodiazepine withdrawal are the two substance withdrawals that can be fatal! Withdrawal seizures can be the initial clinical presentation. To prevent progression to more severe withdrawal symptoms, benzodiazepines must be used; anti-epileptics do not work to prevent alcohol-related seizures.

It is important to know the stages of alcohol withdrawal so that symptoms are properly identified and also treated for the correct length of time.

Alcohol Withdrawal Classification by Stages

Stage 1 Stage 2 Stage 3 Stage 4 Stage 5
Time of last drink 6-8 hours 12-24 hours 12-48 hours 2-5 days 1-6 months
Definition Mild withdrawal
(can progress to DT)
Alcoholic Hallucinosis
(can progress to DT)
Withdrawal Seizures Delirium Tremens (DTs)[6], 5% mortality Chronic Alcohol Use
Symptoms • Mild tremors
• Anxiety
• Nausea
• Stable Vitals
• Tremors
• Agitation
• Insomnia
• Hallucination (auditory, visual, tactile)
• Same as Stage 2, but more severe
• Seizures
Unstable Vitals
• Confusion
• Agitation
• Fever
• Tachycardia
• Hypertension
• Diaphoresis
• Autonomic hyperactivity
• Anxiety
• Sleep disturbance

During withdrawal from alcohol, the loss of GABA-A receptor stimulation from alcohol causes a reduction in chloride flux and is associated with tremors, diaphoresis, tachycardia, anxiety, and seizures.[7] The mechanism behind withdrawal symptoms is thought to be due to an imbalance between GABA (decreased) and glutamate (increased).[8]

The Clinical Institute Withdrawal Assessment (CIWA) was developed in Toronto, Canada in the 1980s.[9] It is considered the gold-standard for measurement of alcohol withdrawal symptoms, and is used in the treatment of alcohol withdrawal in an inpatient setting. Whenever a patient scores > 10 on the CIWA, they should be given either lorazepam or diazepam.

The Prediction of Alcohol Withdrawal Severity Scale (PAWSS) is a validated screening tool that uses a combination of symptoms and signs to identifying patients at risk of developing severe alcohol withdrawal syndrome (i.e., withdrawal hallucinosis, withdrawal-related seizures, and delirium tremens).[10][11] The use of this tool is particularly important, as the CIWA does not indicate the probability that the patient will develop severe withdrawal syndrome, and only indicates whether the patient is experiencing withdrawal symptoms. This is particularly important for identifying high risk patients who may need more intensive medical management or prophylaxis.

Should withdrawal be managed as an outpatient or inpatient?

In most cases, alcohol withdrawal can be managed in an outpatient setting. However, there are several contraindications to this, including:
  • Severe psychiatric/medical comorbidity, or coexisting illness that requires inpatient treatment
  • Electrolyte disturbances/dehydration
  • Current severe alcohol withdrawal, especially with delirium
  • No possibility for follow-up
  • No reliable contact person to monitor the patient
  • Pregnancy
  • Seizure disorder or history of alcohol withdrawal seizures
  • Suicide risk
  • History of delirium tremens or seizures

Inpatient Alcohol Withdrawal Management

Uncomplicated withdrawal Complicated withdrawal
Definition No history of siezures or delirium tremens A history of withdrawal seizures, delirium tremens, pregnancy or geriatric
Management • Diazepam 20mg PO q1-2h until CIWA < 10
• Lorazepam 2mg q1-2h until CIWA < 10
• Load with diazepam 20mg q1h x 3 = 60mg
• Lorazepam 2mg q1h x 3 = 60mg total to start
• Then administer CIWA based on symptoms

Think about the specific symptoms scored on the CIWA!

Think about the patient's scores: are they showing objective signs of autonomic instability in the score? A delirious person might score on AH/VH/agitation and have a “positive” CIWA!

Outpatient Alcohol Withdrawal Management

Sample Taper:
Diazepam 10mg QID x 3 days (total 40mg daily)
Diazepam 10mg BID x 3 days (total 20mg daily)
Diazepam 10mg qHS x 3 days (total 10mg daily)
Thiamine 300mg PO daily x 1 month

Thiamine deficiency (vitamin B1) is common in patients with alcohol dependence. Cognitive impairments may be an early consequence of thiamine deficiency and Wernicke's encephalopathy is under-diagnosed and under-treated.[12]

It is important to supplement patients with PO or IV thiamine. Thiamine 100mg TID should be prescribed as ongoing supplementary therapy in alcohol use disorder patients identified as at risk for thiamine deficiency. [13] For the more severe cases, 200mg IV thiamine x 3 days, followed by oral supplementation is appropriate. Those with suspected Wernicke’s encephalopathy should receive thiamine 100mg IM/IV x 3 days, then 300mg PO x 3-12 months. Don’t forget to give fluids as well!

Folate deficiency is also common in chronic alcoholism.[14]

One may want to switch patients to lorazepam instead if blood work shows significantly elevated liver enzymes or if there are signs of acute liver failure (e.g. - jaundice).

Diazepam or Lorazepam?

The LOT benzodiazpines (Lorazepam, Oxazepam, and Tamazepam are metabolized via glucuronidation (Phase II metabolism), which is less dependent on global liver function. Thus, these benzodiazepines can be used in individuals with severe liver impairment.

  • Diazepam has a long half-life, multiple active metabolites, and should only be used in healthy patients with no signs of liver disease.
  • Lorazepam can be used in patients with hepatic impairment. It has an intermediate length half-life, and no metabolites. This makes it more suitable for use in the elderly, those with severe liver disease, respiratory distress, or if they already on existing opioids (to reduce the risk of respiratory depression). It can also be given in IM form reliably.

When managing alcohol withdrawal, drug-drug interactions should be considered. If patients are on mood stabilizer like lithium or valproic acid, ensure that appropriate levels are drawn to make sure they are not suffering from medication-related toxicity. Lithium levels may increase due to increased diuresis from alcohol, and lithium toxicity can cause tremulousness and nausea (mimicking alcohol withdrawal). Valproic acid combined with with alcohol use increases risk of liver damage, and this can increase valproic acid levels due to decreased metabolism from the liver.

There is the most evidence for naltrexone, followed by acamprosate, gabapentin, and finally, disulfram. Naltrexone and acamprosate are recommended to treat patients with moderate to severe alcohol use disorder in specific circumstances (e.g., when non-pharmacological approaches have not produced an effect or when patients prefer to use one of these medications). Topiramate and gabapentin are also suggested as medications for patients with moderate to severe alcohol use disorder, but typically only after trying naltrexone and acamprosate first.

Alcohol Dependence Treatment

Name Mechansim Dose Side Effects Contraindications Notes
Naltrexone • Blocks mu opioid receptor and reduces the euphoria of EtOH • 25mg PO daily x 3 days, then increase to 50mg PO daily
• Can titrate up to 150mg PO daily
• No need to abstain before starting
Can cause reversible elevations in AST/ALT, order first at baseline, and check again in 1 month's time. Stop if more than 3x LFT elevation. Can also cause GI side effects. Contraindicated in opioid use, due to it competitively displacing opioid medications from their binding sites and precipitating withdrawal.
• Hepatitis
• Liver Failure
Particularly effective for those who report a high euphoria immediately after drinking. Naltrexone has a NNT of about 9.
Acamprosate (“Acampral”) • Glutamate antagonist, mimics GABA
• Not entirely understood
• Restores normal balance of neuronal excitation?
• 666mg TID
• 333mg TID if renal impairment
Diarrhea, anxiety • Severe renal impairment (if GFR < 30)[15] Expensive medication!
Gabapentin • GABA agonist • 100mg PO BID + 300mg PO qHS x 4 days
• Initial dose 300 mg TID (900mg daily)
• Optimal dose is 600 mg TID (1800 daily)[16]
• Low side-effect profile and very well tolerated
• Mild headache, fatigue
- • Gabapentin can be started rapidly in patients with chronic alcohol use because they already have a ramped up GABA system, i.e. - high GABA levels
• In chronic alcoholism, there is ++ GABA activation (EtOH is a GABA agonist), therefore, it is OK to start on a higher dose of Gabapentin
• However, in mild alcohol use disorder, you must slowly titrate up the dose
Topiramate • Alters GABA receptors • 50mg PO daily; titrate by 50mg to a max of 300mg daily • Fatigue, drowsiness, dizziness, nervousness, numbness in hands/feet Like most anticonvulsants, there is an associated risk of birth defects. Taking topiramate in the 1st trimester of pregnancy may increase risk of cleft lip/cleft palate in the infant.
Disulfram (“Antabuse”) • Inhibits aldehyde dehydrogenase
• Increases serum acetaldehyde causing toxic symptoms - nausea, tachycardia
• 125mg PO daily, increase to 250mg daily if reports no reaction to
NNT = 9
• With EtOH: vomiting, flushed face, headache
• Without EtOH: headache, anxiety, garlic-taste, acne, peripheral neuropathy, depressive symptoms
• Can cause severe hypotension and arrhythmias
• To avoid a severe reaction, wait at least 24-48 hours between the last drink and the first drink
• May trigger psychosis at high doses
• Contraindicated in liver cirrhosis, pregnancy, and unstable cardiovascular disease
Relatively poor evidence for efficacy
Baclofen GABA agonist • Initial dose 5mg TID, increase to 10mg TID
• Maximum daily dose 80mg
• Drowsiness, dizziness, weakness, fatigue, headache, trouble sleeping, nausea and vomiting, urinary retention, or constipation. Hallucinations and seizures have occurred on abrupt withdrawal of baclofen. Therefore, except for serious adverse reactions, the dose should be reduced slowly when the drug is discontinued.

Alcohol Use Disorder Guidelines

Guideline Location Year PDF Website
Canadian Guidelines on Alcohol Use Disorder Among Older Adults Canada 2020 - Link
British Columbia Centre on Substance Use (BCCSU) Canada 2019 Link Link
National Institute for Health and Care Excellence (NICE) UK 2011 - Link
American Psychiatric Association (APA) USA 2018 - Link