Substance misuse Flashcards
Biological factors in aetiology of substance misuse
Genetic predisposition (up to 50% heritability)
Neurobiological differences in EEG activity
Differences in receptor systems (e.g. DA) in brain
Psychological factors in aetiology of substance misuse
Personality: Anxious (incl disorder, esp social anxiety), Impulsive (e.g. in ADHD)
Psychiatric Hx (esp childhood): depression, PD
Positive reinforcement: Drugs lead to behaviours that increase their use
Social factors in aetiology of substance misuse
Social network: Key component of recovery, peer pressure, FHx of substance use
Legal: Price/availability/illegal status
Social norms: Acceptability
Social status: Isolation, unemployment, relationship issues
ICD-10 criteria for substance dependence
3 or more of the following:
Tolerance
Withdrawal/drinking to stop withdrawal
Compulsion to drink
Persistent drinking in the face of harm
Loss of ability to control drinking (reinstatement after abstinence)
Neglect of other activities
ICD-10 criteria for ‘harmful use’ of substances
Clear evidence of harm to physical/mental health of user (i.e. already caused harm)
5 stages of change for stopping subtance abuse
Threshold for ‘lower risk’ drinking
<14 units per week
Threshold for higher risk drinking
>50 units pw for males
>35 units per week for females
Receptor systems affected by alcohol
GABA: Acts as agonist, responsible for most effects
NMDA: Antagonist, reduces glutamate transmission
Opioid/DA: To lesser extents
Net effect: GABA > glutamate (acutely)
Psychopharmacology of chronic alcohol dependence
Compensatory increase in glutamate –> imbalance (glutamate >>> GABA) during withdrawal –> excitotoxicity
Screening tools for alcohol dependence
CAGE
FAST (4-question)
AUDIT (10 question)
What is the CAGE questionnaire?
Screening tool for alcohol dependence
Have you ever felt you should Cut down?
Annoyed by people criticizing your drinking?
Guilty about your drinking?
Eye-opener drink in the morning?
2+ = CAGE +ve
Assessment for alcohol use
- Type of drink + quantity
- Duration
- Withdrawal/dependence signs
- Full neuro, cognitive + liver (abdo exam)
- LFTs (esp GGT), FBC (esp MCV, anaemia), Urate (in men), Carbohydrate-deficient transferrin
- AUDIT, CIWA
FAST questions
- How often have you consumed >8/>6 units of alcohol in one sitting in the last year?
- How often have you failed to do what was expected of you due to drinking in the last year?
- How often were you unable to remember what happened the night before due to drinking in the last year?
- Has a relative, friend, or healthcare professional ever been concerned about your drinking or suggested you cut down?
Blood test changes associated with alcohol misuse
Unexplained macrocytosis
Unexplained LFT disturbance
Reduced platelets
Raised carbohydrate-deficient transferrin (identifies drinking in past 1-2 weeks)
Medical harm from alcohol
Liver: Damage, cirrhosis
CV: Cardiomyopathy, HTN
GI: Pancreatitis, varices, peptic ulcer
Cancer: Mouth, throat, oesophagus, liver
Blood: Macrocytosis, anaemia, haemochromatosis
Neurological harm of alcohol misuse
Blackouts
Epilepsy
Wernicke/Korsakoff syndrome
Neuropathy
Cerebellar degeneration
Dementia
Fetal alcohol syndrome
Psychiatric harm of alcohol misuse
Alcoholic hallucinosis: auditory, occurs in clear consciousness c.f. withdrawal
Suicide (10% of alcohol dependent)
Anxiety
Depression
Pathological jealousy
Features of acute alcohol withdrawal
Tremors
Sweating
Nausea/vomiting
Agitation/anxiety
Seizures
Auditory hyperacusis
Visual disturbances
Delirium tremens (5%)
Screening tool for alcohol withdrawal
CIWA-Ar
Onset of alcohol withdrawal symptoms
4-12h after last drink, lasts 2-5d
Rationale for pharmacological detox during acute alcohol withdrawal
Give benzodiazepine (usually chlordiazepoxide) for 5-7d in reducing dose to allow GABA/GLU balance to normalise
Chlordiazepoxide alternative in severe liver failure
Oxazepam, lorazepam (shorter half-life –> less liver accumulation)
Pharmacological management of acute alcohol withdrawal
10-30mg chlordiazepoxide qds (up to 50 for severe dependence) in reducing dose for 7 days
Autonomic features of delirium tremens
Autonomic:
- Sweating
- Pupil dilation
- Hypertension, tachycardia, instability
- Insomnia
- Dehydration + electrolyte disturbance –> fatal arrhythmia
Neurological features of delirium tremens
Coarse tremor
Delirium - confusion, disorientation
Psychiatric featurers of delirium tremens
Classic triad:
- Transient persecutory delusions, paranoia
- Visual hallucinations
- Fear/agitation
Onset of delirium tremens
24-48 hours (but up to 7d) after cessation of drinking, usually with intercurrent illness (e.g. UTI)
Management of delirium tremens
Physical:
- ECG + electrolytes –> fluid/haemodynamic management
- Treat inter-current illness
Pharmacological:
- Oral/IM lorazepam for sedation
- Optimise detox medication (raise dose)
General:
- Low-lit, quiet environment
- 1:1 nursing
- Inform security
- MCA assessment + plan
Pathophysiology of wernicke’s syndrome
Acute encephalopathy due to vitamin B1 deficiency leading to degeneration of mamillary bodies + frontal lobe white matter
Features of wernicke’s syndrome
Delirium
Ataxia
Ophthalmoplegia/nystagmus
Hypothermia/hypotension, tachycardia
Neuropathy
Treatment of wernicke’s encephalopathy
IV thiamine (Vitamin B1) for 3-7d (beware risk of anaphylaxis)
Oral thiamine for 1/12
Prognosis for Wernicke’s
20% mortality
80% of survivors develop Korsakoff’s
Differential causes of Wernicke’s
Brain tumour
Prolonged vomiting: hyperemesis gravidarum in pregnancy, chemotherapy
Malabsorption syndromes
Clinical features of Korsakoff’s
Anterograde amnesia
Some retrograde amnesia –> islands of memory
Confabulations
Due to damage of hippocampus/mamillary bodies
Management of Korsakoff’s
Thiamine for 2 years
OT assessment + ongoing support
Prognosis of Korsakoff’s
20% complete recovery
25% significant recovery
55% no change
How should you treat hypoglycaemia in alcohol-dependent patient
Give IV thiamine first to prevent precipitating Wernicke’s
Role of acamprosate in treatment of alcohol misuse
Enhances GABA transmission
Reduces cravings but pt must not be drinking
Started on day 1 of detoxification
Role of naltrexone in alcohol misuse treatment
Blocks opioid –> reduces reward from alcohol
Can be taken while not abstaining (e.g. prophylactically before big night)
Role of disulfiram in alcohol abuse treatment
Blocks acetaldehyde dehydrogenase –> increase acetaldehyde –> flushing + headache + hypotension
Threat of unpleasant consequences –> -ve reinforcement of alcohol drinking
Should not be used in severe liver damage, recent heart disease, suicidal ideation
Prognosis of relapse in alcohol misuse
50% relapse within 6 months
FRAMES approach to drinking interventions
Feedback about drinking
Responsibility of pt for change emphasised
Advice on how to stop drinking given
Menu of options for stopping drinking
Empathy
Self-efficacy of patient –> empowering
Management of alcohol dependence, biological
- Withdrawal: Inpatient detox, community detox with benzo/thiamine
-
Relapse prevention: Bio
- Pharmacological: Disulfiram, acamprosate, naltrexone, nalmefene
- Vitamin supplementation
Management of alcohol dependence, psychological
Psychoeducation: Family, patient, safe drinking/withdrawal advice, self-help guidance
Consultation: FRAMES, motivational interviewing (decisional balance, readiness ruler)
Outpatient f/u: screen for co-morbid psychiatric condition
Turning point
Marital/family therapy
Management of alcohol dependence, social
Employment, social support
Residential/therapeutic communities (e.g. AA)
Positive prognostic factors for alcohol dependence
Strong motivation
Strong social/occupational structure
Good insight
Indications for inpatient detox
- Alcohol Hx:
- Past Hx of seizures/DT
- Hx of failed community detox
- Severe alcohol dependence
- Current psych:
- Symptoms of Wernicke’s-Korsakoff
- Current confusion/delirium
- Polysubstance misuse
- High suicide risk
- Lack of stable home environment
- Current physical
- Severe malnutrition/N+V
- Concurrent physical/psychiatric illness
- Older age
Effects of cannabis intoxication
Anxiety, paranoia
Mellowness, giggling
slurring of speech, reduced coordination
Reddening of eyes
Active substances in cannabis
THC (main active ingredient) + cannabidiol (mild antagonist to THC, antipsychotic)
Levels vary in different strains
Adverse effects of cannabis
Increased risk of pneumothorax
Precipitate angina
Worsen schizphrenia prognosis
Precipitate schizophrenia
Cognitive impairment in long-term heavy users
Reduced concentration, memory, motivation
Sleep disturbance
Effects of opioids
Euphoria
Analgesia
Pupillary constriction
Respiratory depression, hypotension, hypothermia, bradycardia
N+V, constipation
Features of opioid withdrawal
GI: Vomiting, diarrhoea, abdominal pain
Face: Pupil dilation, runny nose + eyes
Neuromuscular: Restlessness, insomnia, myalgia
Autonomic: Sweating, tachycardia
Onset 6h after last dose, peak 36-48h
First-line treatment for symptomatic relief of opioid withdrawal
Lofexidine
Onset of opioid withdrawal
8-12h after last dose
Duration of opioid withdrawal
10d, with peak at 24-48h
Adverse effects of opioids
Infection: Phlebitis, HIV, HCV
Psychiatric: 14x risk of suicide
Overdose
Mortality 12x
Social: Crime, poverty, etc..
Pharmacological management of opioid dependence
Methadone
Buprenorphine
Dosing of methadone
Oral, start 30mg and increase slowly to reach therapeutic dose (60-120mg)
High risk of overdose!
Benefits of buprenorphine over methadone
Partial agonist –> ceiling effect –> lower risk of OD + less sedating
May ppt withdrawal during conversion
Psychological interventions for opioid dependence
Relapse prevention therapy (CBT)
NA programme
Residential programmes (therapeutic communities)
Relapse rate opioid dependence
40% at 6 months
Symptoms of opioid overdose
Respiratory depression/arrest
Pinpoint pupils
Bradycardia, hypotension
Management of opioid overdose
Naloxone until spontaneous ventilation returns
Features of stimulant use (amphetamines, cocaine, MDMA)
Elevated mood, energy, insomnia
Over-talkativeness
Pupil dilation, tachycardia, high BP, dry mucous membranes
Hyperpyrexia + dehydration (esp MDMA)
Features of amphetamine withdrawal
Depression, lethargy, suicidality, craving
Psychiatric effect of prolonged amphetamine use
Paranoid psychosis
Mood swings + depression
Formication (somatic hallucination) –> scabs
Management of acute stimulant misuse
Benzo and/or antipsychotic
TCA for depression if necessary
Effects of ketamine intoxication
Euphoria
Synaesthesia, hallucinations
Nausea
Ataxia, slurred speech
Adverse effects of ketamine
Fatal overdose
Permanent bladder damage (haemmorhagic cystitis)
Physical dependence
Psychosis, depression
Memory impairment
Management for harmful substance use, biological
Bio:
- Monitor physical health issues (eg. infx)
- Substitute prescribing/withdrawal management
- Contraception, needle exchange
Management for harmful substance use, psychological
Education
Self-help, SMART goal setting
Treatment of underlying psychiatric conditions
Marital/family therapy
Management for harmful substance use, social
Employment/accommodation support (assigned social worker)
Help establishing new interests
Peer support group (e.g. NA)
