Toxicology

Question 1

QRS widening drugs

Answer 1

TCA
Class 1a: quinine, procainamide
Class 1c: flecanide 
LA: bupivocaine, cocaine
BB: propanolol
Carbamazepine 
Diltiazem
Amantidine
Chloroquine

Question 2

Theophylline:
High risk toxicity
Features
Investigations

Answer 2

High risk:
Over 60 and chronic
200mg tablet in 10kg child
K < 3 or BSL >10
>50mg/kg

Features
GI, CNS (tremor, seizure agitation) tachyarrythmias, RAGMA, low K, high BSL

Ix:
Levels repeat 2hrly (55-110mmol/L therapeutic), 550mmol/L fatal

Question 3

Exacerbations of lithium tox

Answer 3

Dehydration
Renal failure
Hyponatraemia
Hypothyroidism
Nephrogenic DI
Drugs: NSAIDS, ACEI, Thiazides, topiramate

Question 4

Grades of lithium tox (chronic)

Answer 4

1: tremor, hyperreflexia, ataxia
2: low GCS, rigidity
3: coma, seizures, myoclonus

Dialysis if neuro symptoms or >2.5mmol/L

Question 5

Colchicine toxicity sequence

Answer 5

Day 1: GI and volume loss
Day 2-3: BM suppression, MOF, acidosis
> 1 week: transient alopecia, myopathy, neuropathy

Question 6

Colchicine management

Answer 6

Activated charcoal for any ingestion
MDAC
G-CSF
Supportive
ECMO

ICU if 500mcg/kg (pill/kg)

Question 7

Essential oil ingestion (hydrocarbon) symptoms

Answer 7

GI
Mucous membranes irritation
CNS (seizure, coma)
Pulm: chemical pneumonitis
Haemodynamic instability 

Supportive management. Home 4 hours

Question 8

Funnel web

• symptoms
• treatment
• disposition

Answer 8

Neuro: agitation, oral parasthesia, fasciculations, coma
Cardiac: APO, shock
Autonomic: salivation, sweating, piloerection, lacrimation
General: headache, nausea, vomiting

Mx:
2 amps in 200mls over 20 mins 2 hourly
Dobutamine 2mcg/kg/min
PBI
Atropine for wet symptoms 
Arrest = 4 amps neat

D/C:
6 hours no symptoms
12 hours post AV

Question 9

LA toxicity

• early symptoms
• late symptoms
• management

Answer 9

Early:
Perioral numbness
Agitation
Tinnitus
Dizziness

Late:
Unstable CNS, CVS, apnoea +/- MetHb

Management:
Seizures
Fluid/inotropes
Bicarb 
20% intralipid 1ml/kg over minutes followed by 0.25ml/kg/min (max 8)

Question 10

Hunter criteria

Answer 10

Spontaneous clonus
Inducible clonus & diaphoresis
Ocular clonus & diaphoresis
Tremor & Hyperreflexia
Inducible clonus & hypertonia with fever

Question 11

Ethylene Glycol Management

Answer 11

Correct low Ca and BSL
Fomepizole 15mg/kg 30 mins then 10mg/kg onwards
Ethanol 800mg/kg then 100mg/kg/hr
(Shots 8 then 2 every hours)
Sodium Bicarbonate
Dialysis (acidosis, renal failure, shock)
Thiamine & pyrodoxine 100mg IV both

Question 12

Chlorine toxicity

Answer 12

Mild: lacrimation, rhinorrhea, cough
Severe: pneumonitis, ARDS, red eyes, unstable, acidosis

Endoscopy <24 hrs if:
Oral burns
Vomiting
Drooling
Abdominal pain

Question 13

Carbamazepine MOA

Answer 13

Na blocker: ataxia, seizure, coma
NA reuptake inhibitor: shock, QTc
Anticholinergic: dry and delirium

Question 14

Quetiapine overdose

Answer 14

<3g: sleepy, tachy
>3g: seizure, coma, hypotension, QTc

Avoid adrenaline
4 or 8 hrs observation (IR/MR)

Question 15

Aminita

• appearance
• phases
• management

Answer 15

Olive green cap
White gills not attached to stalk
Skin on stalk

> 6 hours GI symptoms
2-3 days latent period
MOF

Decontaminate: AC & MDAC
NAC
Silibinin 5mg/kg IV
BenPen 300mg/kg BD then 150 BD

Question 16

Small pupils tox

Answer 16

Clonidine
Opioid
Phenothiazine
Organophosphates (cholinergics)

Question 17

Organophosphate MOA

Answer 17

Muscarinic: wet and 3 Bs
Nicotinic: fasciulations, tachy, tremor, Resp muscle weakness
CNS: coma, seizures, agitation

Question 18

Delayed organophosphate symptoms

Answer 18

Intermediate syndrome: paralysis D3
Delayed neuropathy weeks
Chronic neuropsychiatric

Question 19

Organophosphate investigations

Answer 19

RBC activity: severity
Plasma cholinesterase activity: exposure
Mixed cholinesterase test: reduced activity indicated need for pralidoxime

Question 20

Organophosphate management

Answer 20

Decontaminate (remove clothes and wash)
Early intubation
Atropine 2mg doubling every 5 mins
(20%/hr effective dose) (50mcg/kg kids)
Pralidoxime 2g IV then 500mg/hr
Consider FFP 2 units/day

Question 21

Paracetamol stages

Answer 21

<24 hours: asymp, GI upset
1-3 days: RUQ pain, LFT & INR
3-4 days: fulminant liver failure, RAGMA, MOF
2 weeks: death or recovery

Question 22

Activated charcoal in paracetamol

4

Answer 22

Normal release 2hrs toxic dose
Extended release 4hrs toxic
Massive >30g within 4 hours
Massive ER >30g within 24 hours

Question 23

Hydrofluoric acid

Answer 23

Hydrogen ions immediate pain
Flouride ions delayed pain

Delayed painful blistering place blanching skin
Inhalation: ARDS, pneumonitis, stridor
Ingestion: perforation / haemorrhage
Systemic: depletion in Ca, Mag & K
(Torsade, QTc, tetany)

Tx:
5% topical CG gel
Sub cut CG (0.5ml per cm2)
Biers with 10ml 10% mixed with 40ml NS
Intra-arterial above mix over 4 hours 
Systemic: 60ml every 5 minutes, bicarb, Mg, K

Question 24

Blue ringed octopus

Answer 24

Tetradotoxin (Na channel)
Descending paralysis
PBI, intubated until settles
No painful sting

Question 25

Box Jellyfish

Answer 25

Immediate severe pain
Collapse
Cross hatched welts
No PBI, give vinegar & cold pack

AV:
6 neat in arrest
3 in 100ml NS unwell
1 in 100ml for refractory pain

Question 26

Irikunji octopus

Answer 26

Massive catecholamine release
Delayed pain with no skin changes
ICH, APO, muscle pain, high output HF
Tx: GTN

Question 27

CCB decontamination

Answer 27

Charcoal: 6/12 hours IR/SR
WBI: <4 hours, no symptoms, cooperative, lethal dose (>10 tabs)

Question 28

HIET how to do

Answer 28

50ml 50% dextrose with 1u/kg
Then infuse above hourly
Replace K if low
Aim euglycamia and SBP >90

Question 29

CO elimination t1/2

Answer 29

RA: 4 hours
02: 90 mins
HBOT: 23 mins