Substance Abuse - Level 1/2/3 Flashcards
How much paracetamol risks severe liver damage?
- Causes severe liver damage if >12 tablets/150mg per kg taken
When to admit paracetamol overdose to hospital?
o If >75mg/kg in less than 1 hour – admit to hospital
Pathology of paracetamol overdose?
o Metabolised by CYP450 enzymes to toxic N-acetyl-p-benzoquinone imine (NAPQI) which is conjugated with glutathione before elimination
o NAPQI accumulation causes hepatocellular necrosis
o Renal failure results from acute tubular necrosis
Risk factors of paracetamol overdose?
o Alcoholics o Drugs which induce hepatic enzymes (St John’s Wort, anticonvulsants, rifampicin) o Malnutrition o Anorexia o Cachexia o HIV
Symptoms and signs of paracetamol overdose?
o Nausea and vomiting, abdominal discomfort
o Untreated patients: Vomiting continues beyond 12 hours Pain and tenderness over liver (from 24 hours) Jaundice (at 2-4 days) Sometimes coma from hypoglycaemia
o Renal Failure
Loin pain, haematuria, proteinuria
o Hepatic Failure
Bleeding
Hyperventilation (metabolic acidosis)
DIC, cerebral oedema
Investigations of paracetamol overdose?
o Bloods - Paracetamol levels, FBC, U&Es, LFTs, INR, glucose o ABG (if appropriate) o ECG (if appropriate) o TOXBASE used for managing drug overdose
- LFTs normal until >18h after overdose
- Prolonged INR (from 24h after overdose)
- ALT and AST raised after 3-4 days
- Bilirubin rises over 5 days
Initial management of paracetamol overdose?
o ABC, clear airway
Simple airway manoeuvres
Oropharyngeal or nasopharyngeal airway if reduced consciousness
Consider ventilation
o Activated Charcoal 1g/kg (max 50g)
If <1h after OD, ingestion >150mg/kg paracetamol
Investigations to performed in paracetamol overdose?
o Bloods – FBC, U&E, LFT, INR, HCO3, ABG
o Blood paracetamol levels at 4h post-ingestion
Further management of paracetamol overdose - what?
IV Acetylcysteine (Parvolex) of 3 consecuative infusions over total of 21 hours
• IVI 150mg/kg in 200ml 5% dextrose over 1h
• IVI 50mg/kg in 500ml of 5% dextrose over 4h
• IVI 100mg/kg in 1L of 5% dextrose over 16h
Further management of paracetamol overdose - when?
- If over-line of treatment
- Presentation of 8-24h after overdose of >150mg/kg
- If over 24 hours, give Acetylcysteine immediately and seek expert help
Further management of paracetamol overdose - if ingestion time unknown, staggered (first dose to last >1 hour) or presentation 8-24 hours from ingestion of >150mg/kg?
Get senior advice
Start Acetylcysteine immediately
When can you discharge patient with paracetamol overdose?
After treatment course of Acetylcysteine and asymptomatic with normal LFTs, serum creatinine and INR
Prognosis of paracetamol overdose?
- Treatment within 8h of ingestion is very effective in preventing liver and renal damage
- Later treatment less effective but worthwhile
Names of opiates?
morphine, diamorphine (heroin), pethidine, codeine, buprenorphine, methadone, etc
Mechanism of opiates?
Opioid agonist, binds to endorphin receptors
Effects of opiates?
o Warm feeling, euphoria, relaxed, analgesic, constricted (pin-point) pupils, untethering from worries or concerns
o Opiate dependency develops in weeks and associated with withdrawal symptoms
Poisoning symptoms of opiates?
o Coma o Respiratory depression Usually within 1h causes death Methadone is long-acting so can be delayed over 24-48h o Pinpoint pupils o Cyanosis, apnoeas o Convulsions o Hypotension o Non-cardiogenic pulmonary oedema – from ‘main-lining’ heroin
Investigations of opiate overdose?
o Bloods Paracetamol levels FBC, U&Es, LFTs, INR, glucose o ABG (if appropriate) o ECG (if appropriate) o TOXBASE used for managing drug overdose
Initial management of opiate overdose?
o Maintain airway
o Ventilate with O2 in bag and mask or ET tube
Management of opiate overdose if patient rousable, not cyanosed and RR>8?
o If patient easily rousable, not cyanosed and RR>8 – observe
Management of opiate overdose if coma, bradypnoea (RR<8)?
Naloxone if coma or bradypnoea (<8breath/min) and monitor for response
400mcg IV, then 800mcg for up to 2 doses at 1 minute intervals, then up to 2mg for 1 dose then review diagnosis
In drug addicts – naloxone precipitates feature of opiate withdrawal
• Diarrhoea and cramps – settle or responds to Lomotil
Further management of opiate overdose?
o Sedate as needed
o Observation for 6 hours after last naloxone dose
o Register opiate addiction and refer for help
Severity of aspirin overdose?
o 150mg/kg – Mild
o 250mg/kg – Moderate
o >500mg/kg - Severe
Early features of aspirin overdose?
o Vomiting, dehydration, hyperventilation, tinnitus & deafness, vertigo, sweating
Other features of aspirin overdose?
o Low GCS, seizures, low BP, heart block and pulmonary oedema
General management of aspirin overdose?
o Consult TOXBASE
o Fluids if low BP
o ECG monitoring - Sinus tachycardia, prolonged QT, dysrhythmias
o Activated charcoal if present within 1 hour if >125mg/kg of aspirin ingested
Investigations of aspirin overdose?
- Bloods
o Paracetamol levels
o Salicylate levels – repeat at 2 hours if large overdose until peak
o FBC, U&E, (AKI, low K, Ca, Mg), LFT, glucose, INR
o ABG:
Initially respiratory alkalosis due to stimulation of CNS respiratory system but then develop metabolic acidosis - Urine
o Catheter, measure pH
Management of aspirin overdose?
- Correct acidosis
o If plasma salicylate >500mg/L – alkalinisation of urine with sodium bicarbonate IV over 3 hours
o Aim for urine pH 7.5-8.5 - Dialysis
o If late features, levels >700mg/L or severe metabolic acidosis
Current guidelines for alcohol ingestion?
- Current guidelines suggest men and women don’t regularly exceed 14 units per week, spread over 3 days
Definition of harmful drinking?
- Harmful drinking is defined as a pattern of alcohol consumption causing health problems directly related to alcohol
Criteria for alcohol dependence?
o Craving o Tolerance o Withdrawal: sweats, nausea, tremor o Preoccupation with alcohol and continued drinking despite harmful consequences o Prioritise drink o Tried to stop? Failed?
Epidemiology of alcohol dependence?
- Alcohol dependence affects 1 in 20 people in UK
- Men 2:1 Women
Physiology of alcohol?
o Alcohol enhances GABAergic transmission (anxiolytic effects), releases dopamine in mesolimbic system (euphoriant effects) and inhibits NMDA transmission (amnesic effects)
Risk factors of alcohol dependence?
o Men, lower socioeconomic class, young o Family history of dependence o Bereavement o Unemployment o Job area o Price
Symptoms of alcohol intoxification?
o Elevated mood
o Socialisation
o Disinhibition
Withdrawal signs of alcohol dependence?
o Agitation
o Tremor
o Nausea
o Sweating
Symptoms of delirium tremens?
o Increased pulse o Decreased BP o Tremor o Fits o Visual or tactile hallucinations (insect crawling on skin)
Mechanism of Wernicke-Korsakoff syndrome?
- Neuronal degeneration secondary to thiamine (B1) deficiency
- Alcoholism decreased thiamine intake, absorption from GI tract and utilisation in cells
Symptoms of Wernicke encephalopathy?
• Acute onset triad - Confusional state - Opthalmoplegia, nystagmus - Wide-based gait ataxia • Memory disturbance, hypotension, peripheral neuropathy, hypothermia
Symptoms of Korsakoff’s syndrome?
- Hypothalamic damage and cerebral atrophy due to thiamine deficiency
- Poor laying down of new memories, confabulation
- Lock of insight
- Features of Wernicke’s encephalopathy
Screening assessment of alcohol dependence?
o CAGE questionnaire
• Have you ever felt you should cut down on your drinking?
• Has anyone ever annoyed you by criticising your drinking?
• Have you ever felt guilty about your drinking?
• Have you ever had a drink early in the morning as an eye-opener?
• If 2 or more then ask:
- What is most alcohol you’ve drank in single day and week?
o AUDIT questionnaire
Investigations in alcohol dependence?
o Blood alcohol concentration
o Blood
• FBC, LFTs, etc
• Elevated ALP, MCV, yGT and CDT markers for excess alcohol consumption
Management of alcohol dependence - general advice?
o Drinking advice
• Men and women recommended 14 units or less per week
• >2 alcohol free days per week
• Spread over several days
• Do not drink alone
• Pace drinking
• Alternate soft drinks or drink with meal
• Plan alternative activities to replace drinking periods
o If deficient in thiamine then consider thiamine
Management of alcohol dependence - if hospital admission and abstinent?
• Immediate drug therapy in hospital:
- For 1st 3 days give chlordiazepoxide PO/PR/IVI
- Decrease dose after few days and convert to PO
Management of alcohol dependence - aiming for abstinence - psychological therapy?
o Psychotherapy (FORWARD Leeds) • Motivational interviewing - Aimed to move person through stages of change • Self-help/Group therapy (AA) • CBT • Counselling
Management of alcohol dependence - aiming for abstinence - pharmacological management?
Disulfiram
Naltrexone
Acamprosate
Mechanism of disulfiram in alcohol dependence?
Produces nasty reaction if alcohol taken)
a. Irreversible inhibition of acetaldehyde dehydrogenase (ALDH) which converts alcohol into water and carbon dioxide
b. Build-up of ALDH causing flushing, headache, nausea, vomiting and tachycardia
c. Prescribe once abstinent
d. SE: Halitosis, headache
Mechanism of naltrexone in alcohol dependence?
Opioid receptor antagonist, reduces pleasure it gives)
a. Antagonises endogenous endorphins released by alcohol consumption
b. Must be given once abstinent
c. SE: GI upset, anxious, headache, fatigue
Mechanism of acamprosate in alcohol dependence?
a. Enhances GABA transmission to reduce cravings
b. Once abstinent
c. SE: GI upset, pruritis, rash, altered libido
Management of delirium tremens?
o Admit and monitor vital signs
o For 1st 3 days give chlordiazepoxide/diazepam PO/PR/IVI
o Decrease dose after few days and convert to PO
Management of Wernicke’s Korsakoffs syndrome?
o High dose IV/IM thiamine (Pabrinex – B1, 2, 6, 12, C) over 1 week and then oral for a long period – 2 years for Korsakoff’s syndrome
o ¼ of Korsakoff’s reversible but ¼ need long-term institutional care
Driving issues - with alcohol misuse?
• Loss of licence until 6-months (group 1) or 1-year (group 2) period of abstinence or controlled drinking achieved
Driving issues - with alcohol depedence?
- Loss of licence until 1-year (group 1) or 3-year (group 2) period of abstinence with normalisation of blood parameters
- Consultant support may be required
Complications of alcohol dependence?
o Fatty liver, hepatitis, cirrhosis o Poor memory, cortical atrophy o Arrhythmias, high BP, cardiomyopathy o Osteoporosis o Decreased fertility o Malignancy o Crime and Suicide o Wernicke’s Korsakoff syndrome
Investigations in uncomplicated alcohol withdrawal in hospital?
Bloods
• FBC, LFTs, etc, B1, folate, B12
o Elevated ALP, MCV, yGT and CDT markers for excess alcohol consumption
BP and TPR every 4 hours
Management in uncomplicated alcohol withdrawal in hospital?
o Chlordiazepoxide (10-50mg QDS PO and PRN for 2 days), wean over 7-10 days Alternative: Diazepam 5-10mg PO o Lorazepam if seizures o CIWA-Ar used to guide treatment o Thiamine (Pabrinex) if indicated
Epidemiology of cigarette smoking?
- Smoking prevalence around 15%
- Higher in Irish, Pakistani, Bangladeshi
- Related to deprivation
- 2/3 who smoke say they want to quit
Harms of smoking?
o Main cause of premature death and preventable illness in UK
o 50% chance of dying early (10 years average)
o After 35, person loses 3 months of life expectancy for every year smoked
Effects of stopping smoking?
- Within 20 mins – pulse normal
- Within 8 hours – oxygen levels normal, circulation improves
- Within 24 hours – nicotine eliminated
- Within 48 hours – sense of taste and smell improve
- Within 72 hours – breathing easier
- With months – coughing, appearance improve
Withdrawal symptoms of smoking?
o Usually temporary and caused by adaptation to long-term smoking
o Weight gain
• Presents a minor health risk compared to risk of smoking
• Often progressive for number of years and average ex-smoker gain 5-9kg if not effort for healthy diet made
- Lasting <48h - Light-headedness
- Lasting <1 week - Disturbed sleep
- Lasting <2 weeks - Poor concentration
- Lasting <4 weeks -Irritability, aggression, depression, restlessness, nicotine cravings
- Lasting >10 weeks - Increased appetite
Management of someone wanting to stop smoking?
o Refer to local smoking cessation service
• Offers behavioural support (individual or group), advice for treatments, supply medications needed
Practical advice given to people wanting to stop smoking?
• Best way to stop is combination of behavioural support and medication
• Set a date and commit
• Usually improves after 3rd or 4th day
• Cravings set off by stress, seeing others smoke or alcohol
- Manage cravings by: exercise, talking to friends, keep busy
• One puff almost always leads to going back to smoking regularly
Drug treatments in smoking cessation programmes - NRT?
- Available as patches (16h and 24h) and fast-acting lozenge or spray PRN
- Start on quit date
- To last person until 2 weeks after stop date
Drug treatments in smoking cessation programmes - varenicline?
- Partial nicotinic receptor agonist
- Alleviates cravings and withdrawal and reduces reward
- Start 7-14 days before quit date and for 12 weeks
Drug treatments in smoking cessation programmes - bupropion?
- Weak but selective dopamine and noradrenaline re-uptake inhibitor
- Start 7-14 days before quite date and for 7-9 weeks
Follow up in someone who has stopped smoking?
- 2 weeks in NRT
- 3-4 weeks in varenicline or bupropion
- Measure CO level 4 weeks after - <10ppm is non-smoker
When can’t you prescribe varenicline or bupropion?
Pregnant
Breastfeeding
Children<18
Risk factors for ilicit drug use?
o Young age, male gender o Low socioeconomic class o Psychiatric disorders o Impulsive personality o Genetic
