14th February 2025

Alcohol and substance misuse

Overview of alcohol and substance misuse

Alcohol and substance misuse disorders describe substance use that continues despite harmful consequences. These include injury, physical illness, mental illness and functional impact. Cannabis is the globally most used drug, second is amphetamines. In recreational drug users, polysubstance use is common. National alcohol intake recommendations are a maximum of 14 units per week for any gender.

The patient may present seeking help for the substance dependence itself, its harmful consequences, or substance withdrawal.

Risk factors for alcohol and substance misuse include:

• History of other alcohol or substance misuse
• History of mental illness
• Alcohol: family history of alcohol or substance misuse, anxiety traits, pre-existing anti-social behaviours
• Opioids: male, young, history of prescribed opioid therapy

Risk assessment is always important, including physical, psychological, social and neglect-related harms. If the patient is responsible for the care of children or dependents, safeguarding must be considered.

Clinical features of alcohol and substance misuse

Short and long-term effects

Clinical features associated with abuse of alcohol and key illicit drugs are shown in Table 1. Other commonly misused drugs include inhalants, hallucinogens, anabolic steroids and prescribed drugs.

Table 1 Short and long-term effects of alcohol and key illicit drugs

For most of the above toxicity presentations, management is supportive, with a couple of exceptions:

• Opioid toxicity: naloxone (opioid antagonist) is a life-saving treatment given in respiratory depression
• Orally ingested drugs: activated charcoal can be given within 1 h of ingestion to prevent further absorption

Wernicke-Korsakoff syndrome

This is a reversible-to-irreversible cognitive deficit syndrome resulting from thiamine deficiency, often in the context of alcohol misuse. The classic triad of symptoms in Wernicke’s encephalopathy is acute confusion, gaze palsy and gait ataxia. Korsakoff’s syndrome describes the progression to chronic irreversible cognitive impairment. They can be thought of as a single condition with a spectrum of presentations.

Withdrawal

The most important substance withdrawal syndromes are with alcohol and opioids. These can occur unexpectedly in patients admitted for unrelated reasons, as they may not openly admit to heavy alcohol or opioid use.

Table 2 Alcohol and opioid withdrawal syndromes

Investigations in alcohol and substance misuse

There are no laboratory tests for harmful use or dependence, as these depend on an assessment of drinking or drug-taking behaviours. The below can support diagnosis, monitoring and treatment.

• Alcohol:
  • LFTs: deranged in chronic alcohol use, particularly GGT elevation
  • FBC, B12, folate, thiamine: macrocytic anaemia resulting from dietary deficiencies
• Drugs: urine drug screen

Management of alcohol and substance misuse

Psychological interventions are the mainstay of treatment for many substance misuse disorders, with a supportive, non-judgemental doctor-patient relationship as the first step towards this. In alcohol and opioid misuse, pharmacological therapies can be used alongside psychological therapies, particularly for more severe cases.

Psychological interventions

These include patient education, motivational interviewing, psychological therapies (e.g. cognitive behavioural therapy, CBT, behavioural therapy, family therapy, group drug counselling) and psychosocial services (e.g. counselling, employment, housing).

Alcohol: pharmacological interventions

At any opportunity, oral or parenteral thiamine supplementation should be provided to prevent Wernicke-Korsakoff syndrome.

Following successful alcohol withdrawal, the medications below can be continued for 6 months or longer and are used in combination with psychological interventions, not in isolation:

• First-line: acamprosate or naltrexone – reduce craving and relapse
• Second-line: disulfiram – induces unpleasant symptoms such as vomiting if alcohol is consumed. This carries additional risks of arrhythmias and hepatotoxicity

Alcohol: withdrawal management

Long-acting benzodiazepines (e.g. chlordiazepoxide, diazepam) reduce withdrawal symptoms and increase detoxification success. These can be given as a tapering-dose regimen or a variable-dose regimen based on symptoms (assessed using the CIWA-Ar scale, Clinical Institute Withdrawal Assessment of Alcohol Scale, revised).

Doses should be reduced in patients who are very young, very old or have liver impairment. Lorazepam is preferable in liver impairment as it relies less on hepatic metabolism.

Comorbidity

In concurrent alcohol misuse and substance misuse with opioids, stimulants, benzodiazepine or cannabis, both conditions should be actively treated. There is added risk of mortality in combined alcohol and opioid use.

With comorbidity of alcohol misuse and mood disorders, alcohol misuse should be treated first. If the patient has a significant and/or high risk mood disorder, psychiatry referral may be needed. Otherwise, they should be reassessed after 3-4 weeks of abstinence or reduction, as alcohol habits disrupt psychological interventions for mood.

References

• Editorial Team, BMJ Publishing Group. Overview of substance use disorders and overdose [Internet]. BMJ Best Practice. 2022 [cited 2022 Mar 1]. Available from: https://bestpractice.bmj.com/topics/en-gb/986
• Patkar AA, Lee JC, Burgess DM, Bhatia K, Musham S. Opioid use disorder [Internet]. BMJ Best Practice. 2020 [cited 2022 Mar 1]. Available from: https://bestpractice.bmj.com/topics/en-gb/200
• Karch SB, Wolff K. Cocaine use disorder [Internet]. BMJ Best Practice. 2022 [cited 2022 Mar 1]. Available from: https://bestpractice.bmj.com/topics/en-gb/199
• Stolbach A. Cocaine overdose [Internet]. BMJ Best Practice. 2021 [cited 2022 Mar 1]. Available from: https://bestpractice.bmj.com/topics/en-gb/340
• Albertson TE. Amfetamine use disorder [Internet]. BMJ Best Practice. 2020 [cited 2022 Mar 1]. Available from: https://bestpractice.bmj.com/topics/en-gb/201
• NHS. Alcohol Support [Internet]. NHS. 2018 [cited 2022 Mar 1]. Available from: https://www.nhs.uk/live-well/alcohol-support/calculating-alcohol-units/
• National Institute for Health and Care Excellence. Alcohol-use disorders: diagnosis, assessment and management of harmful drinking and alcohol dependence [Internet]. NICE. 2011 [cited 2022 Mar 1]. Available from: https://www.nice.org.uk/guidance/cg115/chapter/1-Guidance
• National Institute for Health and Care Excellence. Alcohol-use disorders: diagnosis and management of physical complications [Internet]. NICE. 2010 [cited 2022 Mar 1]. Available from: https://www.nice.org.uk/Guidance/CG100
• Wang GS. Cannabis (marijuana): Acute intoxication[Internet]. Burns MM, Traub SJ, Ganetsky M, editors. UpToDate. 2019 [cited 2022 Mar 1]. Available from: https://www.uptodate.com/contents/cannabis-marijuana-acute-intoxication
• Cocaine [Internet]. Talk to Frank. 2019 [cited 2022 Apr 10]. Available from: https://www.talktofrank.com/drug/cocaine
• Heroin [Internet]. Talk to Frank. 2018 [cited 2022 Apr 10]. Available from: https://www.talktofrank.com/drug/heroin