Toxicology Flashcards
Indications and contraindications to activated charcoal
Ingestion within 1 hour of potentially toxic substance
Contraindications:
- low binding affinity for charcoal (iron, lithium)
- Decreased LOC
- Risk of GI bleed
Drugs causing anticholinergic toxidrome
Anticholinergics - benztropine, atropine
TCAs
Antipsychotics - chlorpromazine, quetiapine
Antihistamines - chlorpheniramine, promethazine
Antispasmodics - oxybutynin
Anticholinergic toxidrome presentation
Mad as a hatter - Confusion, delirium
Blind as a bat - Mydriasis
Dry as a bone - Dry skin, urinary retention
Red as a beet - Flushed skin
Hot as a hare - fever
Palpitations
Seizures
Drugs causing cholinergic toxidrome
Organophosphates
Carbamates - insecticide
Pilocarpine - treatment dry eyes and mouth
Neostigmine - reverses neuromuscular blockade
Donepezil
Mushrooms
Sarin nerve gas
Types of opioid overdose
Intentional
Unintentional recreational or prescribed
Unintentional iatrogenic
Presentation for opioid overdose
Miosis
Hypopnoea <12 breaths/min
Stupor
With suggestive history
Management of opioid overdose
Airway management
Naloxone
Beware rebound sedation as naloxone wears off
Check for transdermal patches
Check signs of IVDU
Check for compartment syndrome
Causes of sympathomimetic overdoses
Amphetamines
Ritalin
Cocaine
Pseudoephedrine
Caffeine
Symptoms of sympathomimetic overdose
Symptom onset within 2 hours, life-threatening complications 2-6 hours
Agitation, hyperalert, paranoia, mania, psychosis
Mydriasis
Tachycardia, tachypnoea, hypertension, arrhythmia
Tremor, hyperreflexia, seizure, diaphoresis
Management of sympathomimetic overdose
Asymptomatic - observe at home for 4 hours
Symptomatic - medical observation, cardiac monitoring, bloods, and cooling
Benzos for agitation, psychosis, seizure
Triad of symptoms in serotonin syndrome
- CNS - agitation, confusion, altered mental state, seizures
- Neuromuscular - clonus, myoclonus, hyperreflexia, rigidity, tremor
- Autonomic disturbance - hyper/hypotension, tachy/bradycardia, hyperthermia, dysrhythmia, flushing, sweating, mydriasis
Hunter Serotonin toxicity criteria
Use of serotonergic agent in last 5 weeks AND
- Spontaneous clonus
- Inducible clonus + agitation or diaphoresis
- Ocular clonus + agitation or diaphoresis
- Tremor + hyperreflexia
- Ocular clonus OR inducible clonus + rigidity OR hypotonia + hyperthermia
Drugs causing serotonin syndrome
SSRIs, SNRIs
Opiates + fentanyl, tramadol, pethidine
TCAs
MAOis
Mood stabilisers: Lithium, sodium valproate
Linezolid (abx)
Ondansetron, metoclopramide
Rec drugs - amphetamines, LSD, ecstasy
Herbal - St John’s wort, ginseng
Cardinal features of neuroleptic malignant syndrome
Other symptoms
Use of neuroleptic or withdrawal of anti-Parkinsonian medications within last 4 weeks
Temp >38
Muscle rigidity
Tachycardia, labile BP, dehydration, SOB, altered mental state, pseudo-Parkinsonism, incontinence, dysphagia, diaphoresis, salivation
Rate of ETOH metabolism
One standard drink, 10g ETOH, per 1 hour