Substance Misuse

Question 1

How does the ICD-10 classify substance misuse?

Answer 1

The ICD-10 classifies substance misuse disorders according to the type of substance and the type of disorder.

Question 2

Briefly describe the pathophysiology and aetiology of substance misuse

Answer 2

Question 3

According to the ICD-10 Classification of substance misure, what is acute intoxication?

Answer 3

Acute intoxication: the acute, usually transient, effect of the substance.

Question 4

According to the ICD-10 Classification of substance misure, what is harmful use?

Answer 4

Harmful use: recurrent misuse associated with physical, psychological and social consequences, but without dependence.

Question 5

According to the ICD-10 Classification of substance misure, what is dependence syndrome?

Answer 5

Dependence syndrome: prolonged, compulsive substance use leading to addiction, tolerance and the potential for withdrawal syndromes.

Question 6

According to the ICD-10 Classification of substance misure, what is withdrawal state?

Answer 6

Withdrawal state: physical and/or psychological effects from complete (or partial) cessation of a substance after prolonged, repeated or high level of use.

Question 7

According to the ICD-10 Classification of substance misure, what is psychotic disorder?

Answer 7

Psychotic disorder: onset of psychotic symptoms within 2 weeks of substance use. Must persist for more than 48 hours.

Question 8

According to the ICD-10 Classification of substance misure, what is amnesic syndrome?

Answer 8

Amnesic syndrome: memory impairment in recent memory (impaired learning of new material) and ability to recall past experiences. Also defect in recall, clouding of consciousness and global intellectual decline.

Question 9

According to the ICD-10 Classification of substance misure, what is residual disorder?

Answer 9

Residual disorder: specific features (flashbacks, personality disorder, affective disorder, dementia, persisting cognitive impairment) subsequent to substance misuse.

Question 10

Who is commonly affected by substance misuse?

Answer 10

Substance misuse is more common in ♂ at a ratio of 3:1 (♂:♀).

Question 11

What is the most commonly abused drug?

Answer 11

Cannabis is the most consumed illegal drug, used by 5% of the population.

Question 12

What are the physical, psychological and social impact of drug use?

Answer 12

Physical: death, infection (HIV, hepatitis A, B or C, Staphylococcus aureus, group A Streptococci, Clostridium, TB), endocarditis, superficial thrombosis, deep vein thrombosis, pulmonary embolus.

Psychological: craving, anxiety, cognitive disturbance and drug-induced psychosis.

Social: crime, imprisonment, homelessness, prostitution and relationship problems.

Question 13

What is substance dependence?

Answer 13

Substance dependence describes a syndrome including behavioural, physiological and psychological elements.

Patients are physiologically dependent if they show tolerance or withdrawal. ≥3 of the following manifestations must have occurred over 1 month:

1. Strong desire (compulsion) to consume substance;
2. Preoccupation with substance use;
3. Withdrawal state when substance ingestion is reduced or stopped ;
4. Impaired ability to control substance-taking behaviour (e.g. onset, termination or level of use);
5. Tolerance to substance, requiring more consumption for desired effect;
6. Persisting with use, despite clear evidence to the harmful effects .

Question 14

Give examples of class A drugs and the law surrounding possession and distribution

Answer 14

Examples: crack cocaine, cocaine, ecstasy, heroin, LSD, methamphetamine, methadone and magic mushrooms

Possession: up to 7 years in prison and/or unlimited fine

Distribution: up to life imprisonment and/or unlimited fine

Question 15

Give examples of class B drugs and the law surrounding possession and distribution

Answer 15

Examples: amphetamines, barbiturates, cannabis, ketamine and methylphenidate

Possession: up to 5 years in prison and/or unlimited fine

Distribution: up to 14 years in prison and/or unlimited fine

Question 16

Give examples of class C drugs and the law surrounding possession and distribution

Answer 16

Examples: anabolic steroids, benzodiazepines, khat and gamma-hydroxybutyrate (GHB)

Possession: up to 2 years in prison and/or unlimited fine (excluding anabolic steroids)

Distribution: up to 14 years in prison

Question 17

Briefly discuss about how to take a history surrounding substance misuse

Answer 17

Substance misuse is often a sensitive issue to ask questions on. As such, in an OSCE you will be awarded marks for rapport and empathy , active listening and a non-judgemental attitude.

It is useful to divide your history into:

• Current use (including ‘ TRAP ’ [type, route, amount and pattern] and exploring the signs of dependency)
• Risk assessment (suicide/ self-harm as well as IV use/needle sharing)
• Possible triggers or stressful life events
• Past substance use
• Physical, psychological and social complications of drugs abuse (e.g. future use)
• Coping strategies

Question 18

Briefly discuss the examination of a patient with substance misuse

Answer 18

Perform a full systems examination including respiratory, cardiovascular, gastrointestinal and neurological, and a full set of observations is required including RR, HR, BP and neurological observations (including GCS).

Question 19

What investigations should be ordered for substance misuse?

Answer 19

Bloods including:

1. HIV screen, Hep B , Hep C and tuberculosis testing → risk of blood-borne infections is thought to be greater through needle sharing
2. U&Es to check renal function
3. LFTs and clotting to check hepatic function
4. Drug levels

Urinalysis: drug metabolites (e.g. cannabis, opioids) can be detected in urine.

ECG for arrhythmias, ECHO if endocarditis suspected (secondary to needle sharing).

Question 20

What differentials should be considered for substance misuse?

Answer 20

Psychiatric disorders: psychosis, mood disorders, anxiety disorders and delirium.

Organic disorders: hyperthyroidism, CVA, intracranial haemorrhage and neurological disorders (e.g. cerebellar pathology).

Question 21

Briefly differentiate between detoxification and maintenance therapy

Answer 21

Detoxification refers to a process in which the effects of the drug are eliminated in a safe manner (a replacement drug is weaned) such that withdrawal symptoms are avoided, in an attempt to attain abstinence.

In maintenance therapy abstinence is not the priority, rather the aim is to minimize harm (e.g. from IV drug use).

Question 22

What vaccination is required for those at risk of sharing needles?

Answer 22

Hep B immunisation must be considered for those at risk.

Question 23

Briefly discuss the psychological input offered to those with substance misuse

Answer 23

Motivational interviewing to help with controlling the substance misuse and CBT (for co-morbid depression or anxiety) may be offered.

Contingency management is a technique that focuses on changing specified behaviours by offering incentives (e.g. financial) for positive behaviours such as abstinence.

Supportive help can be in housing, finance and employment.

Help with co-existing alcohol misuse and smoking cessation should be offered.

Self-help groups, e.g. Narcotics Anonymous and Cocaine Anonymous .

Consider the issue of driving and review the DVLA guidelines.

Question 24

Briefly describe the management of opioid dependence

Answer 24

Biological therapies include methadone (first-line) or buprenorphine for detoxification and maintenance.

Naltrexone is recommended for those who were formerly opioid-dependent but have now stopped and are motivated to continue abstinence.

Question 25

What medication is given following a opioid overdose?

Answer 25

Intravenous naloxone (opioid antagonist) can be used as an antidote to opioid overdose.