Other OD's Flashcards
How do benzodiazepines work?
- Enhance effect of the neurotransmitter gamma-aminobutyric acid (GABA)
- Resulting in sedative, anxiolytic, anticonvulsant and muscle relaxant effects.
- These properties of benzodiazepines make them a particularly dangerous drug to take in overdose
What are clinical features of benzodiazepine OD?
- Reduced level of consciousness (including coma): if severe this can result in loss of airway tone and reflexes leading to hypoxia if left untreated.
- Respiratory depression: low RR can –> hypoxia and inadequate tissue perfusion.
- Hypotension
- Bradycardia
- Rhabdomyolysis
- Hypothermia
What else can cause the patient’s OD?
Dual pathology, which may relate to the pt’s OD
- Trauma secondary to falls (e.g. head injury)
- Aspiration pneumonia secondary to a reduced level of conciousness
How are benzodiazepine OD’s managed?
Flumazenil
The majority of overdoses are managed with supportive care only due to the risk of seizures with flumazenil.
It is generally only used with severe or iatrogenic overdoses.
what is the classic presentation of a benzodiazepine OD?
CNS depression with normal or near-normal vital signs.
Many patients will still be arousable and even provide a reliable history.
Sx:
- Slurred speech
- Ataxia
- Atered mental status
- Agitation
- Euphoria
- Blurred vision
- Slate-grey cyanosis
What are features of a beta-blocker OD?
bradycardia
hypotension
heart failure
syncope
How is a beta-blocker OD managed?
If bradycardic: atropine
in resistant cases, glucagon may be used
Is haemodialysis effective in beta-blocker OD?
No
What may also be present in beta-blocker OD and how is this managed?
Hypocalcaemia may also be present, and should be corrected with calcium.
What is lithium used for?
Mood stabilising drug used most commonly prophylactically in bipolar disorder but also as an adjunct in refractory depression.
What is the therapeutic range for lithium?
Very narrow (0.4-1.0 mmol/L)
And long half-life
How is lithium excreted?
By kidneys mainly
At what concentrations does lithium concentration usually form?
> 1.5 mmol/L
What may precipitate lithium toxicity?
Dehydration
Renal failure
Drugs:
- Diuretics (especially thiazides)
- ACEi/ARB
- NSAIDs
- Metronidazole
What are features of lithium toxicity?
coarse tremor (a fine tremor is seen in therapeutic levels)
hyperreflexia
acute confusion
polyuria
seizure
coma
How is Lithium toxicity managed?
Mild-moderate:
- May respond to volume resuscitation with normal saline
Severe:
- Haemodialysis may be needed
Sodium bicarbonate is sometimes used but there is limited evidence to support this. By increasing the alkalinity of the urine it promotes lithium excretion
What are other names for cannabis?
Hash, hashish, weed, pot, ganja, dope, skunk, grass, puff
How is cannabis taken?
Usually smoked
Mixed in food or drink
What are the desired effects of cannabis?
Make pt feel happy and relaxed
Can change the way pt hears or sees things
What are symptoms of a cannabis OD?
Dry cough
Increased appetite
Social withdrawal and paranoia
Altered perception of time
Makes pts more likely to develop shizophrenia
What are Sympathomimetics?
Eg. cocaine
Amphetamines
What are features os sympathomimetic OD?
Tachycardia, mydriasis, euphoria, formication- insects crawling, agitation, tremor, dilated pupils, tachycardia, arrhythmias, convulsions.
How is a sympathomimetic OD treated?
Benzodiazepine e.g. diazepam
What is the pathophysiology of carbon monoxide toxicity?
- Carbon monoxide binds readily to haemoglobin, forming carboxyhaemoglobin → reduced oxygen-carrying capacity
- In carbon monoxide poisoning the oxygen saturation of haemoglobin decreases leading to an early plateau in the oxygen dissociation curve
What may exam questions re carbon monoxide poisoning hint at?
badly maintained housing e.g. student houses.
What are symptoms of a carbon monoxide OD?
- Headache: 90% of cases
- N + V: 50%
- Vertigo: 50%
- Confusion: 30%
- Subjective weakness: 20%
Severe toxicity:
- ‘pink’ skin and mucosae
- Hyperpyrexia
- Arrhythmias
- Extrapyramidal features
- Coma
- Death
What investigations may be done in carbon monoxide OD and what may they show?
- Pulse oximetry may be falsely high due to similarities between oxyhaemoglobin and carboxyhaemoglobin — Therefore do VBG or ABG
Typical carboxyhaemoglobin levels
< 3% non-smokers
< 10% smokers
10 - 30% symptomatic: headache, vomiting
> 30% severe toxicity
ECG is a useful supplementary investgation to look for cardiac ischaemia
How is a carbon monoxide OD treated?
- Assess in ED
100% high-flow oxygen via a non-rebreather mask
- Decreases half-life of carboxyhemoglobin (COHb)
- Administer ASAP and continue for at least 6 hrs
- Target sats 100%
- Tx continued until all sx resolved, rather than monitoring CO levels
Hyperbaric oxygen
- Evidence base is limited
- Long-term outcome may be bette than just oxygen in severe cases
- For severe cases (eg. levels > 25%) discuss with specialist
Other indications for hyperbaric oxygen:
- LOC at any point
- Neurological signs other than headache
- Myocardial ischaemia or arrhythmia
- Pregnancy
What are street drugs and what are the different categories?
Chemical substances taken for enjoyment, or leisure purposes, rather than for medical reasons
- Psychoactive drugs- Affects Brain
- Illegal Drugs- prohibited for use or production
- Controlled drugs- Drug regulated for Medical use.
What are consequences of street drug use?
- Infections - HIV, hepatitis passed on by needle use
- Addiction
- Cost - expensive, obtaining money can lead to crime
- Social problems - relationships, jobs
- Mental problems - bizarre behaviour, depression, anxiety
- Overdose - v ill or die
- Impure drugs
- Unwanted sexual intercourse under the influence
What are depressant drugs? Examples
Alcohol
Barbituartates
Benzodiazepines
Examples of stimulant drugs?
Speed up brain system
Caffeine
Energy drinks
Nicotine
Amphetamines
Cocaine
Bath salts
Examples of Hallucinogens?
Brain thinks differently- in all senses
Hallucinogen – altered reality
- Marijuana (mild)
- Mushrooms
- LSD
- Spice/K2/Synthetic Marijuana
Examples of club drugs?
Ecstasy
PCP (phencyclidine)
GHB (gamma-Hydroxybutyric acid)
Ketamine
Meth
LSD (Lysergic acid diethylamide)
Rohypnol (Roofies)
Examples of opiate drugs?
Morphine
Heroin
Oxycontin
Percocet
Vicodin/hydrocodone
What are other names for cocaine?
Crack, coke, white, toot, pebbles, freebase
How does cocaine work?
blocks the uptake of dopamine, noradrenaline and serotonin
How does cocoaine make people feel?
It makes people feel super-confident, and alert.
It reduces hunger pangs.
After a big high, there follows a ‘come-down’, or low.
What are adverse effects of cocaine usage?
Cardiovascular:
- coronary artery spasm → myocardial ischaemia / infarction
- Tachycardia and bradycardia
- HTN
- QRS widening and QT prolongation
- Aortic dissection
Neurological:
- Seizures
- Mydriasis
- Hypertonia
- Hyperreflexia
Psychiatric:
- Agitation
- Psychosis
- Hallucinations
Others:
- Ischaemic colitis - consider if pt complain of abdominal pain or rectal bleeding
- Hyperthermia
- Metabolic acidosis
- Rhabdomyolysis
What are features of cocaine toxicity?
Difficulty breathing
Loss of urine control
Cyanosis
Loss of awareness or surroundingsHTN
Death
How is cocaine toxicant managed?
1st line:
- Benzodiazepines
Chest pain:
- Benzodiazepines + glyceryl trinitrate
- If MI develops then PCI
Hypertension:
- Benzodiazepines + sodium nitroprusside
The use of beta-blockers in cocaine-induced cardiovascular problems is debated
- AHA issued statement in 2008 warning against use (due to the risk of unopposed alpha-mediated coronary vasospasm)
- If reasonable alternative is given in exam, choose it
What is LSD?
Synthetic hallucinogen
one of the most potent psychoactive compounds
What are the effects of LSD?
Heightening or distortion of sensory stimuli and enhancement of feelings and introspection
Who are the most frequent LSD users?
Adolescents and young adults
How do patients with LSD toxicity present?
Symptoms
Following acute panic reactions (“bad trips”), massive ingestions or unintentional ingestions
Psychoactive sx:
- Variable subjective experiences
- Impaired judgements, can –> injury
- Amplification of current mood which –> euphoria or dysphoria
- Agitation, appearing withdrawn - especially in inexperienced users
- Drug-induced psychosis
Somatic sx:
- Nausea
- Headache
- Palpitations
- Dry mouth
- Drowsiness
- Tremors
What are signs of LSD intoxication?
Tachycardia
HTN
Mydriasis
Paresthesia
Hyperreflexia
Pyrexia
What manifestations of LSD intoxication can appear quickly?
Manifestations such as tachycardia, hypertension, pupillary dilation, tremor, and hyperpyrexia can occur within minutes following oral administration of 0.5–2 µg/kg.
What complications can a massive LSD OD lead to?
Respiratory arrest
Coma
Hyperthermia
Autonomic dysfunction
Bleeding disorders
What investigations can be done in an LSD intoxication?
Diagnosis based on hx and examination
Most drug screens don’t pick up LSD
How is LSD intoxication managed?
- Dependent on specific behavioural manifestation elicited by the drug
Agitation (from ‘bad trip):
- Supportive reassurance in a calm, stress-free environment
- Benzodiazepines, if above ineffective
LSD-induced psychosis
- May need antipsychotics
Massive ingestions of LSD:
- Supportive care (respiratory support and ET intubation if needed)
- HTN, tachycardia, hyperthermia treated symptomatically
- Hypotension: fluids and then vasopressors if needed
Are activated charcoal and gastric emptying useful in LSD OD?
Because LSD is rapidly absorbed through the GIT activated charcoal administration and gastric emptying are of little clinical value by the time a patient presents to the emergency department.
What are other names for ecstasy?
E, crystal, dolphins, superman, pills, mitsubishis, MDMA, mangy, brownies
How is ecstasy taken?
As a pill
What does ecstasy do?
- Feel high and happy, full of energy
- Colors and sounds more intense
- Feelings of love and affection towards ppl around you
- Effect lasts several hours
What are harmful effects of ecstasy?
- Often no pure, so effects unpredictable
- “comedown” after can make pt feel very low. Can cause depression, anxiety and memory problems
What are other names for amphetamines?
Speed, whizz, sulphur, dexies
How are amphetamines take?
In powder form
What do amphetamines do?
Stimulant - gives more energy
Feel upbeat and excited
What are harmful effects of amphetamines?
Overactive, jittery, anxious
Can cause a severe mental condition where people lose contact with reality and see or hear things that aren’t there (psychosis)
What are other names for heroin?
H, Smack, Skag, Gear, Brown
How is heroin usually taken?
Dissolved into liquid then injected
Can be smoked and snorted
What does heroin do?
Used as a very strong painkiller
Makes one feel calm, happy, relaxed
What are the harmful effects of heroin?
Extremely addictive
Infection through needles (hepatitis or HIV)
What is the Misuse of Drugs Act 1971
To prevent use of harmful drugs
Three classes - A, B, C
Offences:
- Possession of drugs
- Supply of drugs.
- Possession with intent to supply another person
- Offering to supply another person with drugs
- Manufacture of drugs.
- Export or import of drugs.
- Allowing your property to be used for the use, supply or production of drugs
What are Class A drugs?
Most harmful
Eg. cocaine, heroin, ecstasy, LSD, methadone, magic mushroom
Possession: Max 7 years in prison + fine
Supply: life imprisonment + fine
What are class B drugs?
eg. amphetamines, cannabis, mephedrone, codeine, barbiturates
Possession: Max 5 years in prison + fine
Supply: 14 years in prison + fine
What are Class C drugs?
Eg. anabolic steroids, minor tranquilisers
Possession: Max 2 years prison + fine
Supply: 14 years prison + fine
