Recreational Drugs Flashcards
How would serotonin syndrome present
Hypertonia, hypereflexia and clonus
Mental state changes
Autonomic instability inc hyperthermia, sweating, raised HR, mydriasis
What recreational drugs can cause serotonin syndrome
Ecstasy, LSD, amphetamines
How would you differentiate serotonin syndrome and NMS
Serotonin syndrome is quicker onset and reflexes are swift
How is serotonin syndrome managed
Cooling
Benzo’s for agitation
Propofol for rigidity
Cyproheptadine can be given in severe cases
What is ABD characterised by
Mentally - aggressive, violent, struggling, psychotic
Hyperadrenergic - raised temp, sweating, raised HR and RR
What is the typical ABD patient
Acute toxicity on top of long term cocaine use
What are the factors leading to death in ABD
Lactic acidosis, increased O2 demand (which may not be met if restrained etc), risk of arrythmias
How should ABD be managed
Don’t restrain them, ventilate them at the rate they were breathing at, sedation, IV fluids, temperature control
What are your options for sedation in ABD
Benzodiazepines
Good - familiarity, safe
Bad - resp depression, unpredictable dose-response relationship
Ketamine
Good - rapid, predictable, wide therapeutic range
Bad - inhibit catecholamine uptake so worse sympathomimetic effects
Haloperidol
Good - dopamine antagonist
Bad - need ECG, prolong QT, reduced seizure threshold
How would you reserve Benzodiazepines
Flumazenil - GABA antagonist (competitive inhibitor)
What are the risks of giving Flumazenil
Lowers seizure threshold
Cardiac arrhythmia
What is the mechanism of action of Benzodiazepines
Increase the affinity of GABAa receptors for GABA= Cl- influx = hyerpolarised cell
How do benzodiazepines differ from barbiturates
They have less action in the brainstem meaning there is less respiratory depression
What is spice
It’s a synthetic canabinoid
Full agonist at the canabinoid receptor so more potent
How would someone who has taken spice present
Catatonic state Hallucinogenic Increased temp and HR Respiratory depression Risk of MI and seizures
How would you treat someone who has taken spice
Respiratory depression - Naloxone
Agitation - diazepam
Can give Rimonabant (inverse agonist of CB1 receptor)
What is the mechanism of action of ketamine
NMDA antagonist
What effects does Ketamine have
Increased HR, BP, temp and sweat
Respiratory depression
Long term: ulcerative cystitis
How does NOS exert its effects
Anxiolytic - GABA agonist
Euphoric - NMDA antagonist leading to dopaminergic neurone activation and dopamine release
Analgesic - opioid receptor (mu) agonist
What is a long term consequence of NOS
B12 deficiency which can lead to subacute combined degeneration of the spinal cord
What are poppers
Alkyl nitrates
What do poppers do to your HR and BP
Raised HR
Decreased BP - lightheaded
What is the danger of swallowing poppers and how can this be reversed
Leads to methylglobinaemia (Fe2 —> Fe3) leading to Hb having no oxygen carrying capacity
Give methylene blue and oxygen
What is the mechanism of action of opioids
They bind to opioid receptors
Pre-synaptic: close VGCC leading to reduced intracellular Ca and therefore reduced release of neurotransmitter
Post-synaptic: Open K channels leading to K efflux and a hyperpolarized neurone less sensitive to excitatory inputs
Describe the pain pathway and where opioids exert their action
Cortical neurones activate PAG (midbrain) which activate nucelus raphe magnus (medulla) which inhibit spinothalamic tracts
Opioids activate PAG
Why do opioids lead to respiratory depression and bradycardia
Respiratory depression - opioids reduce the medullas sensitivity to O2
Bradycardia - stimulate vagal activity
What is the antidote to opioid toxicity
Naloxone 2mg IV
Talk through some symptomatic management options for recreational drug toxicities
Temperature - cool blankets, cool IV fluids, correct muscle rigidity Acidotic - sodium bicarbonate Raised potassium - glucose and insulin Raised HR - B blocker Raised BP - B blocker or verapamil Seizures - lorazepam
What are some specific risks associated with amphetamine use
Chest pain
Extremely high BP leading to cerebral bleeds
Systems that cocaine affects
Mental state: insomnia, agitated, delusions
Neuro: seizures, aneurysm rupture, haemorrhage
Pulmonary: oedema, pneumothorax, septal perforation, fibrosis
Vascular: thrombosis and infarcts literally everywhere (mesenteric ischaemia, renal infarcts, DVT, stroke)
Cardiac: Chest pain, MI, coronary artery vasospasm, atherosclerosis, arrythmias, chronic HTN, aortic dissection
What is the MOA of cocaine
Blocks pre-synaptic uptake of noradrenaline and dopamine so more at receptors leading to increased catecholamine release
How is cocaine induced chest pain managed
Benzodiazepines to reduced HR, BP and agitation
Aspirin to prevent thrombus
Nitrates eg GTN to reverse coronary vasoconstriction
Labetalol or verapamil for HTN
Sympathomimetic toxidrome and examples
Raised HR, RR, BP, temperature
Sweat
Pupils dilate
Bowels loud
Cocaine, amphetamines, mephedrone, ecstasy, MDMA, LSD
Anticholinergic toxidrome and examples
Increased HR, BP, temperature
Pupils dilate
No sweating
Loud bowel sounds
Atropine
Cholinergic toxidrome and examples
Constricted pupils
Sweating
Loud bowel sounds
Mushrooms
Opioid toxidrome and examples
Reduced HR, RR, BP, temp
Pinpoint pupils
Reduced bowel sounds
Morphine, heroin, tramadol, fentanyl, methadone
Sedative-hypnotic toxidrome and examples
Reduced HR, BP, RR, temp
No change in pupils or bowel sounds
Benzodiazepines, barbituates, ketamine, GHB
