Substance Misuse Flashcards
What is the ICD-10 criteria for substance misuse?
The ICD-10 criteria for substance dependence (for both drugs and alcohol) require three or more of the following to have been experienced at some time during the last year:
- A strong desire or sense of compulsion to take the substance
- Difficulties in controlling substance-taking behaviour in terms of its onset, termination, or levels of use.
- Physiological withdrawal state when usage has ceased or reduced, as evidenced by characteristic withdrawal symptoms or use of the same (or closely related) substance with the intention of relieving or avoiding withdrawal symptoms.
- Evidence of tolerance, such as that increased doses of the psychoactive substance are required to achieve effects originally produced by lower doses
- Progressive neglect of alternative pleasures or interests because of psychoactive substance use and increased amount of time necessary to obtain or take the substance or to recover from its effects
- Persisting with substance use despite its clear evidence of overtly harmful consequences.
What are the risk factors for alcohol dependence?
- Genetics - Twin studies suggest that 25-50% of the predisposition to alcohol dependence is inherited.
- Occupation - Alcohol misuse is associated with certain occupation e.g. publicans, journalists, doctors, the armed forces and the entertainment industry.
- Social background - There is often a history of difficult childhood, with parental separation. Educational achievement is commonly poor and they may be evidence of juvenile delinquency.
- Psychiatric illness - substance misuse is associated with personality disorders, mania, depression and anxiety disorder (particularly social phobia).
What is the differential diagnosis for substance misuse/dependence?
This applies to both alcohol and drug dependence:
- Organic problems may be masked by the symptoms of the intoxication. Confusion, ataxia, or psychotic symptoms may not be due to substance misuse and may have another physical cause.
- Psychiatric illness may be the primary problem or a comorbid problem. Don’t assume that symptoms are due to withdrawal or intoxication. Often patients have a dual diagnosis such as that of depression and alcohol dependence, or personality disorder and drug dependence.
What are the physical complications of alcohol dependence?
- Biological complications include:
- Liver disease (which occurs in 10-20% of alcohol dependent people)
- Gastrointestinal: oesophageal varices, gastritis, peptic ulceration, pancreatitis
- Neurological: peripheral neuropathy, seizures, and dementia
- Cancers: bowel, breast, oesophageal and liver
- Cardiovascular: hypertension and cardiomyopathy
- Head injuries/accidents
- Foetal alcohol syndrome affects babies born to mothers who drink during pregnancy
What are the psychological complications of alcohol dependence?
- Depression, anxiety, self-harm and suicide are increased
- Amnesia due to intoxication
- Cognitive impairment may occur as either alcoholic dementia or Korsakoff’s syndrome
- Alcoholic hallucinosis is the experience of auditory hallucinations in clear consciousness while drinking alcohol. Hallucinations often have a persecutory or derogatory content.
- Morbid jealousy is the overvalued idea or delusion that a partner is unfaithful. It is association with alcohol dependency, impotence, and violence.
What are the social complications of alcohol depedence?
Social complications: Alcohol misuse can become a vicious circle, where social problems precede alcoholism and are then created and perpetuated by continued misuse. Problems include unemployment, poor attendance and performance at work, domestic violence, separation, and divorce. Law breaking may be due to intoxication or more rarely to fund drinking. Children are at increased risk of neglect, abuse, and conduct disorder.
What are the investigations you would perform in someone who is alcohol dependent?
FBC - alcohol abuse causes a macrocytic anaemia due to B12 deficiency
LFTs - gGT rises with heavy alcohol use; raised transaminases suggests hepatocellular damage
AUDIT screening tool to assess baseline dependence.
Additional investigations are guided by the clinical presentations, e.g. an ECG for chest pain, a urine drug screen, hepatitis screening.
Describe the management of alcohol dependence
As with all patients:
- Assess risk in patients with alcohol dependence. Alcohol dependence is related to comorbid depression, anxiety and other psychiatric illnesses as well as suicide. They may need to be admitted to hospital.
- Safeguarding assessment of children and adults under the care of the patient.
Specific for alcohol dependence [NICE + Shorter Oxford Textbook of Psychiatry]:
- Motivation to change should be assessed. Provision of information and advice about the effects of excessive drinking is an important first stage in treatment. If a person requires help empowering themselves to change, motivational interviewing (a form of counselling) can be employed.
-
Detoxification allows metabolism an excretion of the substance while minimising discomfort.
- If the patient is in acute alcohol withdrawal (unplanned) (see Alcohol Withdrawal) offer hospital admission for support and monitoring for withdrawal seizures and delirium tremens.
- If the patient is not yet detoxing (planned), refer to specialist alcohol services who can help carry out alcohol detoxification in the community. This involves a daily visit by health professional and reducing course of benzodiazepines over 5-7 days.
- Some patients can be managed in primary care by structured brief interventions carried out by GPs with specialist interests.
- Relapse prevention in those with mild dependence may be accomplished by high-intensity psychological treatment (cognitive behavioural and problem-solving therapies as well as group therapies may be employed). Those with moderate-severe dependence would also benefit from acamprosate (making drinking unpleasant) or naltrexone (a mu opioid antagonist). Nalmefene is a mu opioid antagonist and also a partial kappa antagonist, which should be taken while drinking to uncouple the reward from alcohol intoxication (see the Sinclair method for why naltrexone should be used in the same way).
- Rehabilitation with the aim of restoring or completely restructuring the person’s life may be done as a residential or a day programme. Organisations like alcoholics anonymous (AA) can provide essential counselling, support and health information.
Describe the mechanism of alcohol withdrawal
- Chronic alcohol consumption enhances GABA mediated inhibition in the CNS (similar to benzodiazepines) and inhibits NMDA-type glutamate receptors. This leads to a downregulation of GABA receptors and upregulation of NMDA receptors.
- Alcohol withdrawal therefore leads to a hyperexcitability state - decreased GABAa and increased NMDA function leads to increased Ca2+ influx. This is harmful as it can cause seizures, which are especially harmful in younger patients. The purpose of preventing withdrawal is to prevent the brain damage which can occur as a result of these. Often parts of people’s brains are ‘fried’ and they cannot drive for a year. Can often be fatal leading to death.
- The more detoxes one undergoes, the more glutamate excitation becomes out of control. This is also associated with increased likelihood to relapse.
- Furthermore, the more detoxes a patient undergoes, the more cognitive impairment they experience.
What are the clinical features of alcohol withdrawal?
What is the onset of symptoms?
Symptoms start at 6-12 hours, which include:
- Tremor of the limbs, tongue, and eyelids
- Sweating and tachycardia
- Anxiety, agitation and insomnia
- Nausea and vomiting
- Seizures which peak at 36 hours
Peak incidence of delirium tremens is at 48-72 hours: coarse tremor, confusion, delusions, auditory and visual hallucinations, fever, tachycardia.
What are the clinical features of delirium tremens?
Peak incidence of delirium tremens is at 48-72 hours: coarse tremor, confusion, delusions, auditory and visual hallucinations, fever, tachycardia.
Describe the management of alcohol withdrawal
Management is important in preventing withdrawal symptoms which can be damaging to the brain.
First-line benzodiazepines e.g. chlordiazepoxide. Typically given as part of a reducing dose protocol.
Carbamazepine also effective in treatment of alcohol withdrawal and is used in other countries.
Describe the clinical presentation of opiate intoxication
IV heroin produces a rush or buzz, with feelings of euphoria, warmth and well-being. Sedation and analgesia follow, and some people vomit or become dizzy.
Bradycardia and respiratory depression occur, which can kill people.
Pinpoint pupils are a classic sign of opiate intoxication.
Describe the clinical presentation of opiate withdrawal
Withdrawal typically begins around 6 hours after injection peaking at 36-46 hours. It is extremely unpleasant but rarely life-threatening.
Dysphoria, nausea, insomnia and agitation occur. As the effects on opiate receptors are reversed, everything ‘runs’: diarrhoea, vomiting, lacrimation and rhinorrhoea; the person feels feverish with abdominal cramps and aching joints and muscles as well as piloerection (hence going cold turkey).
Describe the investigations you would perform in an opiate-dependent person
Examine the person in order to:
- Confirm evidence of drug misuse (e.g. needle tracks, signs of drug intoxication or withdrawal).
- Check for the presence of complications (e.g. poor nutrition, signs of anaemia, skin abscess, thrombophlebitis, viral hepatitis, HIV, chest infection, tuberculosis).
Assess their mental health with a mental state exam (MSE) (e.g. general behaviour, depression, risk of self harm, delusions or hallucinations, confusional states).
Choice of investigations is guided by clinical judgement, but would usually include:
- Full blood count (to exclude anaemia, signs of infection).
- Liver function tests to look for liver damage (hepatitis, alcohol misuse).
- Tests for hepatitis A, B, and C, and HIV (all with informed consent). Pre-testing should never act as a barrier or delay to vaccination, and drug users should have access to hepatitis and B vaccination without testing if desired.
- If substitution therapy is being considered, opioid use will need to be confirmed (so that you’re not accused of being a drug dealer) by testing for the presence of opioids in oral fluids or urine via a urine drug screen (UDS).
