Substance Misuse Flashcards
Subtypes of substance misuse disorder:
ICD-11 Substance Disorder Hierarchy:
- No substance use
- Low-risk use
- Hazardous substance use
- Single episode of harmful substance use
- Harmful pattern of substance use
- Substance dependence
Substance dependence requires at least two of the following:
1) Impaired control over substance use
2) Increasing priority over other aspects of life or responsibility
3) Psychological features suggestive of tolerance and withdrawal
What neurotransmitter does alcohol & opioids interact with?
The inhibitory neurotransmitter GABA –> this disrupts the equilibrium between GABA and glutamate as there are more sedative hormones (GABA).
How does alcohol/opioid dependence (chronic) disrupt the equilibrium between GABA & glutamate? How does this lead to withdrawal symptoms?
The brain will upregulate the natural stimulants to achieve equilibrium. Withdrawal symptoms occur when there is a sudden drop in GABA, resulting in disrupted homeostasis and too much glutamate. The excess natural stimulants lead to withdrawal symptoms such as anxiety, sweating, and shaking.
What are recommendations for weekly alcohol intake according to UK guidance?
14 units a week (for both men and women)
Difference between a) hazardous drinking, b) harmful drinking, and c) alcohol dependence
a) Hazardous drinking is when an individual consumes more than 14 units of alcohol a week, which may increase their risk of harm.
b) Harmful drinking is when the pattern of alcohol consumption directly causes physiological complications and illnesses.
c) Alcohol dependence is characterised by craving and tolerance of alcohol consumption despite the negative complications experienced.
How can individuals with chronic alcohol misuse present?
- Liver cirrhosis
- Alcoholic liver disease
- Bleeding oesophageal varices
- Hepatic failure
- Stigmata of liver disease
- Pancreatitis
- Vitamin deficiencies (e.g. Wernicke’s)
What symptoms can alcohol withdrawal present with?
Withdrawal symptoms can be experienced after a few hours of alcohol cessation.
Within 6-12 hours:
- tremors
- autonomic arousal e.g. tachycardia, fever, pupillary dilation, and increased sweating
Between 12-48 hours of cessation:
- alcohol hallucinosis (typically auditory or tactile).
Between 72-96 hours:
- can present with delirium tremens.
- may experience altered mental status, agitation, and tactile hallucination.
Investigations in the context of alcohol misuse?
- Full blood count: raised MCV, raised platelets, anaemia
- Liver function tests: increased GGT, AST:ALT > 2:1
- Haematinics (B12/folate): alcohol can cause folate deficiency
- Thyroid function tests
Screening tools for alcohol misuse?
- The AUDIT-C questionnaire is a common screening tool that looks at the risk of dependency of alcohol misuse.
- The SAD-Q questionnaire which looks at the severity of alcohol dependence
- The CAGE questionnaire.
What are some psychiatric complications of alcohol misuse?
Alcoholic hallucinosis
Delirium tremens
Wernicke-Korsakoff syndrome
Some complications of alcohol misuse:
Neurological: ischaemic stroke, encephalopathy, seizures, peripheral neuropathy
Cardiovascular: increased rate of myocardial infarction and stroke, hypertension, dilated cardiomyopathy
Hepatology: alcoholic liver disease, liver cirrhosis, liver fibrosis, pancreatitis
Oncology: increased risk of head and neck cancer, oesophageal cancer, liver cancer, breast cancer, colorectal cancer
Psychiatric: alcoholic hallucinosis, delirium tremens, Wernicke-Korsakoff syndrome
What is Wernicke’s encephalopathy? What are the 3 main symptoms?
Thiamine deficiency - thiamine is critical for brain cell function, and deficiency can lead to neuronal death and resulting clinical manifestations.
Triad of symptoms:
1) Ataxia
2) Confusion
3) Ophthalmoplegia/nystagmus
Notably, all three signs do NOT need to coexist in a single patient for a diagnosis.
Management of Wernicke’s? Is it reversible?
It is reversible –> give Pabrinex (thiamine supplementation)
What is Korsakoff’s syndrome?
Korsakoff’s syndrome is a chronic memory disorder, often occurring as a late complication of untreated Wernicke’s encephalopathy.
Hallmark 3 symptoms of Korsakoff’s syndrome?
1) Profound anterograde amnesia (i.e. can’t form new memories)
2) Limited retrograde amnesia (i.e. inability to remember past experiences)
3) Confabulation (patients fabricate memories to mask their memory deficit)
Who is Korsakoff’s most common in?
Primarily observed in chronic alcoholics but may also occur in non-alcoholics with severe malnutrition or malabsorption conditions leading to thiamine deficiency.
Is NOT reversible
Management of Korsakoff’s?
Ongoing thiamine supplementation: To replenish the body’s stores and prevent further neuronal damage.
Cognitive rehabilitation: To improve residual cognitive function and adapt to the memory loss.
Careful management of the patient’s environment: To reduce confusion and disorientation.
Treatment of underlying causes, like alcoholism: This includes counselling and support to cease alcohol consumption.
Presentation of alcohol withdrawal (signs & symptoms):
Presentation of simple withdrawal (6-12 hours after last drink):
- Insomnia
- Tremor
- Anxiety
- Agitation
- Nausea and vomiting
- Sweating
- Palpitations
Presentation of alcohol hallucinosis (12-24 hours post-drink):
- Hallucinations of visual, tactile or auditory origin.
Presentation of delerium tremens (72 hours post-drink):
- Delusions
- Confusion
- Seizures
- Tachycardia
- Hypertension
- Hyperthermia
Why would lorezapam be used over chlordiazepoxide in alcohol withdrawal?
In those with liver disease –> less metabolism by liver
What is delirium tremens?
a severe form of alcohol withdrawal
When does delirium tremens (DT) typically present?
Typically occurrs around 72 hours after the cessation of alcohol intake
Clinical features of delirium tremens?
- Confusion and disorientation
- Hallucinations, which can be visual or tactile (e.g., formication – the sensation of crawling insects on or under the skin)
- Autonomic hyperactivity, manifesting as sweating and hypertension
- Seizures (rarely)
Management of delirium tremens (i.e. immediate management)?
DT necessitates immediate medical attention and management.
1st line –> oral lorazepam
(If symptoms persist, or oral medication is declined, offer parenteral lorazepam or haloperidol)
Then for MAINTENANCE management of alcohol withdrawal:
1. Administer Chlordiazepoxide
2. Ensure adequate hydration with fluids
3. Provide Anti-emetics to manage nausea
4. Pabrinex to replenish vitamins
5. Refer the patient to local drug and alcohol liaison teams for further support and management.
What is 1st line management for DT?
Oral lorazepam
What is the role of Chlordiazepoxide in alcohol detox?
Helps with symptoms of withdrawal
What class of drug is Chlordiazepoxide?
Benzo
What is role of Naltrexone in alcohol detox?
Naltrexone is an opiate blocker that makes alcohol less enjoyable and less rewarding.
It can be administered as an injection once a month or oral tablets.
Common side effects are nausea, vomiting, decreased appetite, pain at the injection site, and increased liver enzymes.
Who is Naltrexone contraindicated in?
It is contraindicated in opiate use and patients with liver failure.
What is the role of Acamprosate in alcohol detox?
Acamprosate is a medication that increases GABA and decreases excitatory glutamate which REDUCES CRAVINGS.
It has a good side effect profile and is generally well tolerated.
What is the role of Disulfiram in alcohol detox?
Disulfiram inhibits acetaldehyde dehydrogenase which causes the accumulation of acetaldehyde with alcohol.
It causes unpleasant symptoms such as flushing, sweating, headache, nausea and vomiting, arrhythmias, and hypotensive collapse.
Patients should avoid alcohol for 24 hours before taking disulfiram and 1 week after cessation of the medication.
When taking the medication, they must avoid ALL contact with alcohol.
Who is disulfiram contraindicated in?
Disulfiram is contraindicated in patients with heart disease, psychosis, and those felt to be at high risk of suicide.
What is it important to prescribe in alcohol detox?
prophylactic oral thiamine, if they are malnourished or in acute withdrawal, or suffer from decompensated liver disease
What drug is used in the management of symptoms in alcohol detox?
Chlordiazepoxide (20-40 mg QDS)
(or lorazepam in liver disease)
What drug is an opiate blocker used in alcohol detox?
Naltrexone
What drug used in alcohol detox can cause nausea and vomiting after drinking alcohol?
Naltrexone
What drug used in alcohol detox reduces cravings?
Acamprosate (by increasing GABA and decreasing excitatory glutamate)
What are some indications for inpatient alcohol withdrawal treatment?
- Patients drinking >30 units per day
- Scoring over 30 on the SADQ score
- High risk of alcohol withdrawal seizures (previous alcohol withdrawal seizures or delirium tremens, or history of epilepsy)
- Concurrent withdrawal from benzodiazepines
- Significant medical or psychiatric comorbidity
- Vulnerable patients
- Patients under 18
Investigations for alcohol withdrawal?
AUDIT and SADQ questionnaires to assess the severity of alcohol misuse.
Blood tests to assess liver function and electrolyte balance.
Neuroimaging may be considered in cases of persistent confusion or seizures.
How can you calculate how many units there are in an alcoholic drink?
By multiplying the total volume of the drink in ml by its ABV (percentage alcohol by volume) and dividing the result by 1,000:
Units = (strength (ABV) x volume (ml)) ÷ 1000
How do opioids affect the CNS?
Opioids are central nervous system depressants that slow brain activity and relax muscles.
Clinical features of opioid misuse (i.e. have just taken it)?
Physiological: euphoria and reduced pain, sedation, respiratory depression, miosis (constricted pupils), constipation, skin warmth and flushing
Psychological: apathy, disinhibition, drowsiness, impaired judgment and attention, slurred speech
Clinical features of opiate WITHDRAWAL?
Agitation
Anxiety and irritability
Muscle aches or cramps
Chills
Runny eyes & nose (rhinorrhoea & lacrimation)
Sweating
Hypersalivation
Yawning
Insomnia
Gastrointestinal disturbance such as abdominal cramps, nausea, diarrhoea and vomiting
Dilated pupils
Piloerection
Increased heart rate and blood pressure
What drugs can be used in the management of opiate withdrawal?
- Methadone
- Lofexidine (a2 receptor agonist)
- Loperamide (for diarrhoea)
- Anti-emetics
- Benzos (for agitation)
N.B. NICE advises against prescribing opiates during opiate withdrawal, but prefers symptomatic management or use of lofexidine.
Side effect of methadone?
QTc prolongation
What 2 drugs to opiate detox programmes use?
methadone and buprenorphine –> these activate opioid receptors in the body and suppress cravings.
Once detox is complete, what drug can be used to prevent opiate relapse? How does this work?
Naltrexone –> binds and blocks opioid receptors and is reported to reduce opioid cravings. There is no abuse and diversion potential with naltrexone.
Lots of patients refuse naltrexone as means they then cannot abuse opiates.
Management of opiate overdose?
Naloxone
What labs can be done in the context of opioid misuse?
HIV and hepatitis B/C: due to the increased risk of blood-borne infection is greater through needle sharing
Tuberculosis testing
Urea & electrolytes
Liver function tests and clotting screen: to check hepatic function
Drug levels: to check for drug toxicity