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
What is the main intervention for opioid misuse?
Opioid detox using methadone reduction
An alternative to this is buprenorphine reduction
What type of receptors are opioid receptors?
G coupled proteins
What is the strength of an opioid goverened by?
The ‘strength’ of an opioid drug is governed by its ability to act as an agonist at the mu receptor (as these produce the greatest analgesic effect) and its potency.
Note, an opioid overdose requires emergency management (RRAPID).
ABCDE approach must be followed.
How does opioid overdose affect breathing?
- Bradypnoea is a common clinical feature of an opioid overdose.
- Hypoxaemia may occur in opioid overdose due to respiratory depression.
How can an opioid overdose affect O2 sats?
Hypoxaemia may occur in opioid overdose due to respiratory depression (may see cyanosis)
What ABG result can be seen in opioid overdose?
Patients with opioid overdose are at risk of developing type 2 respiratory failure (i.e. low SpO2 and raised CO2) due to respiratory depression.
What does the BNF suggest regarding giving naloxone in an opioid overdose?
1) Administer an initial dose of 400 micrograms of naloxone intravenously.
2) If there is no response, administer 800 micrograms for up to 2 doses, at 1-minute intervals (if there is no response to the preceding dose).
3) Seek senior support if there is still no response to naloxone to consider alternative diagnoses or higher doses of naloxone.
4) Further doses may be required if respiratory function subsequently deteriorates as naloxone has a short half-life.
How should naloxone be delivered?
Naloxone can also be administered via the subcutaneous or intramuscular route, however, the intravenous route has the quickest onset of action.
How does opioid overdose affect BP?
Hypotension is also a common clinical feature of opiate overdose.
How does opioid overdose affect capillary refill time?
Capillary refill time may be prolonged in the context of opiate overdose.
Signs and symptoms of opioid overdose?
Typical symptoms of opioid overdose include:
Nausea
Vomiting
Confusion
Drowsiness
Typical clinical signs of opioid overdose include:
Decreased level of consciousness
Respiratory depression
Pin-point pupils
Patient’s who have overdosed on opiates may have signs of hypovolaemia. What should you do in this situation?
1) Insert at least one wide-bore intravenous cannula (14G or 16G).
2) Administer a 500ml bolus Hartmann’s solution or 0.9% sodium chloride (warmed if available) over less than 15 mins (fluid resuscitation)
(Administer 250ml boluses in patients at increased risk of fluid overload (e.g. heart failure))
What blood tests would you want in opioid overdose?
FBC: to screen for anaemia and signs of infection.
U&Es: to assess renal function (impaired renal function can result in the accumulation of opiates).
CRP: to screen for evidence of infection.
Lactate: to screen for evidence of reduced end-organ perfusion.
Coagulation studies: to screen for coagulopathy.
Toxicology screen: to screen for other drugs which may have been taken as part of a mixed overdose.
Why must you be cautious of mixed drug overdoses?
Some opioids come in paracetamol containing preparations, for example, co-codamol and co-dydramol.
It is imperative to investigate and treat for paracetamol overdose, due to the risk of long-lasting and potentially fatal hepatic complications.
In a RRAPID station for opioid overdose, what should you look for under ‘exposure’?
- Evidence of recreational drug use e.g. track marks on the arms
- If the patient is in chronic pain or an end of life patient, they may have a syringe driver or a fentanyl patch which may easily be missed
- Other causes of reduced consciousness/respiratory depression e.g. intracranial pathology.
- Drug paraphernalia
Differentials for opioid overdose?
- Hypoglycaemia
- Post-ictal status
- Overdose with other depressants
- Head injury or other intracranial pathology
- Carbon dioxide narcosis
Investigations in suspected opioid overdose?
Bedside:
1) Vital signs: to see if this patient needs urgent intervention and physiological support e.g. supplemental oxygen for low saturations.
2) Arterial blood gas: to assess for evidence of type 2 respiratory failure and acidosis which may occur in opioid overdose secondary to respiratory depression.
3) Capillary blood glucose: to rule out hypoglycaemia.
Labs:
1) FBC: important to obtain a baseline.
2) U&E: to check if this patient is unknowingly accumulating opioids in their system due to renal impairment.
3) LFTs: to assess if the patient can metabolise their opioid load effectively. Also useful to screen for acute liver damage secondary to overdose (e.g. mixed overdose with paracetamol). Chronically elevated liver enzymes may indicate viral hepatitis (often associated with intravenous drug use).
4) Paracetamol levels: to rule out mixed overdose.
What type of respiratory failure is seen in opioid overdose?
Type 2
Describe the CAGE questionnaire
Do not ask the patient about their alcohol intake before asking the CAGE questions. CAGE questions should NOT be preceded by any questions about alcohol intake as its sensitivity is dramatically enhanced by an open-ended introduction.
C) Have you ever felt that you should Cut down on your drinking?
A) Have people Annoyed you by criticising your drinking?
G) Have you ever felt bad or Guilty about your drinking?
E) Have you ever had a drink first thing in the morning to steady your nerves or get rid of a hangover (known as an Eye-opener)?
The patient should be given 1 point for each question they answer yes to.
A score of over 2 suggests problematic drinking.
How does lofexidine work in opioid withdrawal?
Lofexidine stimulates the alpha-2 receptors of the brain potentially leading to the lessening of noradrenaline levels, a chemical released by the nervous system in response to stress. This helps reduce certain withdrawal symptoms during detox and rehab.
Alcoholic hallucinosis vs delirium tremens?
AH –> It is a psychosis associated with alcoholic withdrawal but patients have exclusively subjective auditory disturbances and report them in clear consciousness
DT –> confused state of a patient with delirium tremens (i.e. patient is unaware)
What are the psychological effects of cannabis?
- Relaxation
- Euphoria
- Altered perceptions
- Irritability
- Paranoia
What are the physical effects of cannabis?
- Dry mouth
- Dry eyes
- Tachycardia
- Hunger
What are some chronic or adverse effects of cannabis?
- Low motivation
- Depression
- Anxiety
- Psychosis
- Associated risks of smoking
What class drug is cannabis?
B
What is the psychoactive component in cannabis? What receptor does it bind to?
THC - binds to CB1 receptors
What neurotransmitter does THC indirectly affect?
Increases dopamine levels
How long does cannabis stay in the body for?
- Days if infrequent use
- Weeks if chronic use
What class drug is MDMA/ecstasy?
A
MOA of MDMA?
Blocks serotonin reuptake, increasing amounts free at synapse.
Also increases dopamine and noradrenaline.
Physical effects of MDMA?
- Hyperthermia
- Dry mouth
- Mydriasis
- HTN
- Tachycardia
- Bruxism
Chronic or adverse effects of MDMA?
- Low mood
- Anxiety
- Overdose
- Hyponatraemia 2ary to water intoxication
What electrolyte abnormality can MDMA cause?
Hyponatraemia
What class drug are amphetamines?
B (A if injected)
Cocaine is A
MOA of amphetamines?
- Disrupts storage of neurotransmitters (dopamine, serotonin, and noradrenaline) in synaptic vesicles
- Increased amounts of these neurotransmitters due to amphetamines causing transporters to run in reverse
Psychological effects of amphetamines?
- Increased energy & focus & concentration
- Agitation
- Aggression
- Psychotic symptoms
Physical effects of amphetamines?
- Tachycardia
- HTN
- Increased RR
- Decreased hunger
- Decreased need for sleep
Chronic effects of amphetamines?
- Psychosis
- Depression
- Anxiety
- Dependence
Withdrawal symptoms in chronic use of amphetamines?
- Cravings
- Low mood
- Increased sleep
- Anhedonia
What class drug is LSD?
A
What receptors does LSD bind to?
5-HT (serotonin) –> causes serotonin release
What neurotransmitters does LSD increase?
- Serotonin
- Glutamate (not as much)
- Dopamine (not as much)
Physical effects of LSD?
- Mild tachycardia
- Mild hyperthermia
- Mydriasis
What is HPPD?
Hallucinogen Persisting Perception Disorder - brief flashbacks or visual perceptual disturbances following hallucinogenic use
Causes problems with driving, heavy machinery etc
What class drug is heroin?
A
MOA of heroin?
- Crosses blood brain barrier and coverted into morphine
- Binds to mu-opioid receptors
- Inhibits GABA causing increase in dopamine
What is effect of GABA on dopamine?
GABA inhibits the release of dopamine
Psychological effects of heroin?
- Euphoria
- Relaxation
- Sense of comfort
- Anxiolytic
Physical effects of heroin?
- Reduced RR
- Bradycardia
- CNS depression
- Constricted pupils
What class drug is cocaine/crack?
A
MOA of cocaine/crack?
Blocks monoamine reuptake transporters –> increased dopamine, noradrenaline, serotonin
Psychological effects of cocaine/crack?
- Elation
- Increased energy
- Confidence
Physical effects of cocaine/crack?
- Dry mouth
- Mydriasis
- Vasoconstriction
- Tachycardia
- Decreased appetite
Chronic/adverse effects of crack/cocaine?
Stroke
Cardiac toxicity
ENT complications
What is the antidote for benzo overdose?
Flumazenil
What are the 2 substitution options for opioid dependence?
1) Methadone
2) Buprenorphine
What is the anti-craving drug in alcohol withdrawal?
Acamprosate
MOA of disulfiram in alcohol detox?
Inhibits aldehyde dehydrogenase –> results in increased serum acetaldehyde.
Produces unpleasant side effects and sensitivity to alcohol e.g. vomiting, sweating, palpitations
What is the deterrent drug in alcohol withdrawal?
Disulfiram
Psychological therapies in drug/alcohol abuse?
- Motivational interviewing
- Brief interventions
- CBT
- Contingency management
- Self help
Social aspects to consider in drug/alcohol abuse?
- Employment
- Training and education
- Housing
- Relationships
- Financial
- Criminal/justice support
What colour is methdone?
Green
how does methadone work in opiate detox?
Substitution therapy
Prevents withdrawal symptoms but does NOT give opiate ‘high’
Starting dose of methadone?
10-30mg daily
Is there a possibility of illicit use on top of methadone use?
Yes
How is methadone taken?
- Liquid
- Tablet
- Injectable (rare)
How is buprenorphine taken?
- Tablet
- Sublingual
- Depot injection
how does methadone work in opiate detox?
Substitution therapy
Prevents withdrawal symptoms but does NOT give opiate ‘high’
Starting dose of buprenorphine?
4mg daily
Is there a possibility of illicit use on top of buprenorphine use?
Why?
No - due to partial antagonist effect (i.e. ‘blocking’
Symptoms of opiate withdrawal vs overdose?
Overdose:
- Respiratory depression
- Bradycardia
- Reduced GCS
- Pinpoint pupils
Withdrawals:
- Lacrimation
- Rhinorrhoea
- Sweating
- Muscle aches
- Agitation
- Excessive yawning
- Tachycardia
- HTN
- Sleep disturbance
- N&V
- Diarrhoea
- Piloerection
Drug for opiate overdose?
Naloxone
MOA of naloxone?
Competitive opiate antagonist
Patients often rapidly regain consciousness
Problem with naloxone?
Short half life compared to long acting opiates.
Induces a massive withdrawal.
May also have to readminister naloxone.
