Recreational Drugs

Question 1

How would serotonin syndrome present

Answer 1

Hypertonia, hypereflexia and clonus
Mental state changes
Autonomic instability inc hyperthermia, sweating, raised HR, mydriasis

Question 2

What recreational drugs can cause serotonin syndrome

Answer 2

Ecstasy, LSD, amphetamines

Question 3

How would you differentiate serotonin syndrome and NMS

Answer 3

Serotonin syndrome is quicker onset and reflexes are swift

Question 4

How is serotonin syndrome managed

Answer 4

Cooling
Benzo’s for agitation
Propofol for rigidity
Cyproheptadine can be given in severe cases

Question 5

What is ABD characterised by

Answer 5

Mentally - aggressive, violent, struggling, psychotic

Hyperadrenergic - raised temp, sweating, raised HR and RR

Question 6

What is the typical ABD patient

Answer 6

Acute toxicity on top of long term cocaine use

Question 7

What are the factors leading to death in ABD

Answer 7

Lactic acidosis, increased O2 demand (which may not be met if restrained etc), risk of arrythmias

Question 8

How should ABD be managed

Answer 8

Don’t restrain them, ventilate them at the rate they were breathing at, sedation, IV fluids, temperature control

Question 9

What are your options for sedation in ABD

Answer 9

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

Question 10

How would you reserve Benzodiazepines

Answer 10

Flumazenil - GABA antagonist (competitive inhibitor)

Question 11

What are the risks of giving Flumazenil

Answer 11

Lowers seizure threshold

Cardiac arrhythmia

Question 12

What is the mechanism of action of Benzodiazepines

Answer 12

Increase the affinity of GABAa receptors for GABA= Cl- influx = hyerpolarised cell

Question 13

How do benzodiazepines differ from barbiturates

Answer 13

They have less action in the brainstem meaning there is less respiratory depression

Question 14

What is spice

Answer 14

It’s a synthetic canabinoid

Full agonist at the canabinoid receptor so more potent

Question 15

How would someone who has taken spice present

Answer 15

Catatonic state
Hallucinogenic
Increased temp and HR
Respiratory depression
Risk of MI and seizures

Question 16

How would you treat someone who has taken spice

Answer 16

Respiratory depression - Naloxone
Agitation - diazepam
Can give Rimonabant (inverse agonist of CB1 receptor)

Question 17

What is the mechanism of action of ketamine

Answer 17

NMDA antagonist

Question 18

What effects does Ketamine have

Answer 18

Increased HR, BP, temp and sweat
Respiratory depression
Long term: ulcerative cystitis

Question 19

How does NOS exert its effects

Answer 19

Anxiolytic - GABA agonist
Euphoric - NMDA antagonist leading to dopaminergic neurone activation and dopamine release
Analgesic - opioid receptor (mu) agonist

Question 20

What is a long term consequence of NOS

Answer 20

B12 deficiency which can lead to subacute combined degeneration of the spinal cord

Question 21

What are poppers

Answer 21

Alkyl nitrates

Question 22

What do poppers do to your HR and BP

Answer 22

Raised HR

Decreased BP - lightheaded

Question 23

What is the danger of swallowing poppers and how can this be reversed

Answer 23

Leads to methylglobinaemia (Fe2 —> Fe3) leading to Hb having no oxygen carrying capacity
Give methylene blue and oxygen

Question 24

What is the mechanism of action of opioids

Answer 24

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

Question 25

Describe the pain pathway and where opioids exert their action

Answer 25

Cortical neurones activate PAG (midbrain) which activate nucelus raphe magnus (medulla) which inhibit spinothalamic tracts Opioids activate PAG

Question 26

Why do opioids lead to respiratory depression and bradycardia

Answer 26

Respiratory depression - opioids reduce the medullas sensitivity to O2 Bradycardia - stimulate vagal activity

Question 27

What is the antidote to opioid toxicity

Answer 27

Naloxone 2mg IV

Question 28

Talk through some symptomatic management options for recreational drug toxicities

Answer 28

``` 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 ```

Question 29

What are some specific risks associated with amphetamine use

Answer 29

Chest pain | Extremely high BP leading to cerebral bleeds

Question 30

Systems that cocaine affects

Answer 30

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

Question 31

What is the MOA of cocaine

Answer 31

Blocks pre-synaptic uptake of noradrenaline and dopamine so more at receptors leading to increased catecholamine release

Question 32

How is cocaine induced chest pain managed

Answer 32

Benzodiazepines to reduced HR, BP and agitation Aspirin to prevent thrombus Nitrates eg GTN to reverse coronary vasoconstriction Labetalol or verapamil for HTN

Question 33

Sympathomimetic toxidrome and examples

Answer 33

Raised HR, RR, BP, temperature Sweat Pupils dilate Bowels loud Cocaine, amphetamines, mephedrone, ecstasy, MDMA, LSD

Question 34

Anticholinergic toxidrome and examples

Answer 34

Increased HR, BP, temperature Pupils dilate No sweating Loud bowel sounds Atropine

Question 35

Cholinergic toxidrome and examples

Answer 35

Constricted pupils Sweating Loud bowel sounds Mushrooms

Question 36

Opioid toxidrome and examples

Answer 36

Reduced HR, RR, BP, temp Pinpoint pupils Reduced bowel sounds Morphine, heroin, tramadol, fentanyl, methadone

Question 37

Sedative-hypnotic toxidrome and examples

Answer 37

Reduced HR, BP, RR, temp No change in pupils or bowel sounds Benzodiazepines, barbituates, ketamine, GHB