Substance Misuse Flashcards
What is the pathophysiology behind substance misuse?
Biological and environmental factors leads someone to take a substance, this causes positive reinforcement which then leads to dependence over time.
What is meant by positive reinforcement?
Reinforcement is what makes you to continue taking the drug which then eventually leads to dependence, reinforcement is either psychosocial reinforcement (from peers or the pleasurable effects of the drug) and biological reinforcement (activates mesolimbic dopaminergic reward pathways)
What is the epidemiology behind substance misuse?
Substance misuse is more common in males than females at a ratio of 3:1
Cannabis is the most used drug (5% of the population)
What are the clinical features of substance misuse?
Physical- death, infection (HIV, Hep A, B, C, staph aureus, group A streptococci, clostridium, TB), endocarditis, superficial thrombosis, DVT, PE)
Psychological- craving, anxiety cognitive disturbance, drug induced psychosis
Social- crime, imprisonment, homelessness, prostitution, relationship problems.
What is substance dependence?
Describes a syndrome including behavioural, physiological and psychological elements, patients are physiologically dependent if they show tolerance or withdrawal
> or equal to 3 of the following manifestations must have occurred over 1 month…
. Strong Desire (compulsion) to consume a substance
. Preoccupation with substance use
. Withdrawal state when substance ingestion is reduced or stopped
. Impaired ability to control substance taking behaviour
. Tolerance to substance, requiring more consumption for desired effect
. Persisting with use, despite clear evidence of the drugs Harmful events.
What questions should you ask in a drug user?
TRAP- trap, route, amounts pattern
Explore dependency- do you feel that taking the drug is on your mind, have you tried reducing the drug your taking, any problems with this? Able to control your consumption? Do you feel that you have to take more of the drug to get the same effect? Are you aware of the harmful effects? (Knowledge of harm)
Make sure to also carry out a risk assesment- suicide/self harm as well as IV use/needle sharing)
What are the investigations carried out for a person who’s misusing substances?
Bloods- HIV screen, Hep B, Hep C and TB testing (the risk of blood borne infections is thought to be greater in needle sharing), U and Es, to check for renal function, LFTs and clotting (checks hepatic function), drug levels
URINALYSIS- drug metabolites (cannabis and opioids) can be detected in the urine.
ECG- for arrhythmias, ECHO if endocarditis is suspected (secondary to needle sharing)
What is the differential diagnosis for substance misuse?
Psychiatric disorders- psychosis, mood disorders, anxiety disorders and delirium
Organic disorders- hyperthyroidism, CVA, intracranial haemorrhage, neurological disorders (cerebellar pathology)
What is the management of substance misuse?
Hep B immunisation must be considered for those at risk
Motivational interviewing to help with controlling substance misuse and CBT for co morbidities May be offered
Contingency management- this focuses on changing specified behaviours by offering incentives ie: financial for positive behaviours
Supportive help with housing, finance and employment
Smoking cessation should be offered
Self help groups
Review DVLA guidelines
What is the difference between detoxification and maintenance therapy?
Detoxification= the process in which the effects of the drugs are eliminated in a safe manner (a replacement drug is weaned) such that withdrawal symptoms are avoided in an attempt to attain abstinence.
Maintenance= abstinence is not the priority, rather the aim is to minimise the harm (eg: from IV drug use).
What are the drugs used for opioid dependence?
Methadone (1st line) or buprenorphine for detoxification and maintenance.
What is recommended in patients who were formerly opioid dependent but have now stopped and are motivated to continue abstinence?
Naltrexone
What can be used as an antidote to opioid overdose?
Intravenous Naloxone
What is the antidote for paracetemol overdose?
IV acetylcysteine
What is alcohol abuse?
Consumption of alcohol at a level sufficient enough to cause physical, psychiatric and/or social harm.
What is binge drinking?
Drinking over twice the recommended level of alcohol per day in one session (more than 8 units for a male and more than 6 units for a female)
What is the recommended limits of alcohol?
14 units per week
What is the pathophysiology behind alcohol?
Alcohol affects several neurotransmitters in the brain eg: it’s effect of GABA causes anxiolytics and sedative effects.
The pleasurable and stimulant effects of alcohol are mediated by a dopaminergic pathway in the brain, repeated and excessive alcohol ingestion causes a sensitisation in this dopaminergic pathway and leads to the development of dependence.
What happens pathologically when you are exposed to alcohol in the long term?
Causes adaptive changes in neurotransmitter systems, down regulation of inhibitory neuronal GABA receptors and up regulation of excitatory glutamate receptors so when alcohol is withdrawn it results in CNS hyper excitability.
What are the risk factors of alcohol abuse?
Male (are at an increased risk of alcohol abuse and have increased metabolism of alcohol and therefore they can have higher quantities) Younger adults Genetics Antisocial behaviour Lack of facial flushing Life stressors
What are the clinical features of alcohol intoxication?
Slurred speech Labile affect Impaired judgement Poor co ordination Severe cases: hypoglycaemia, stupor and coma
