8.4 Toxicology Antidotes

Front 1

What are the 3 main antidotes considered for Cyanide Poisoning ?

Back 1

1. Hydroxycobalamin = First Line 5 grams
[ Directly binds cyanide ]
2. Dicobalt edetate
3. Sodium thiosulfate
[ Enhances cyanide detoxification ]

Front 2

Which of the following antidote links is

incorrect ?

A. Sodium calcium edetate = Lead
B. Succimer (DMSA) = Lead
C. Pralidoxime = Isoniazid
D. Sodium thiosulfate = Cyanide

Back 2

C. Isoniazid = Pyridoxine

Pralidoxime = Organophosphate poisoning

Front 3

What weight based dosages make up the

3 stage N-acetyl cysteine infusion ?

Back 3

1. 150 mg/kg in 200 mL D5W over

15-60 minutes
2. 50 mg/kg in 500 mL D5W over 4 hours
3. 100 mg /kg in 1000mL D5W over 16 hours

Front 4

What dose of Calcium is given for Calcium

Channel Blocker overdose ?

Back 4

Calcium Gluconate 10% 60 mL
[ 9 G/mL elemental calcium ]

OR

Calcium Chloride 10% 20 mL
[ 27 G / mL elemental calcium ]

Front 5

What are the Antidote indications, and what is given for Iron overdose / toxicity ?

Back 5

1. Toxicity
a. Shock
b. HAGMA
c. Altered Mental status (AMS)

2. Serum level > 90 umol/L

( 4/24 post ingestion )

** Desferrioxamine at 15 mg / kg / Hr

Front 6

What are the indications for Dextrose in

overdose ?

Back 6

1. Insulin overdose
2. Sulfonylurea - Oral Hypoglycaemic

toxicity / overdose
3. Utilised in BBlocker / CCB overdose

[ High Dose Insulin Therapy ]

Front 7

What are the indications and the dosing of

DigiFab in acute Digoxin overdose ?

Back 7

Indications :
1. Cardiac arrest 20 ampoules
2. Life threatening arrhythmias
3. K+ > 5 mmol/L
4. Dose > 10 mg (Adult) or 4 mg (child)
5. Level > 15 nmol/L
Haemodynamically unstable = 10 ampoules
Haemodynamically stable = 5 ampoules

Front 8

What are the indications and the dosing of

Digifab in chronic digoxin overdose ?

Back 8

1. Cardiac Arrest 5 ampoules
2. Life threatening arrhythmia
3. GI symptoms (moderate-severe)
4. "Any Symptom" in presence of impaired

renal function.

2 Ampoules
* repeat in 30 minutes if toxicity not

reversed.

Front 9

What are the 4 potential treatment options for methanol poisoning ?

Back 9

1. Folinic acid 2mg/kg IV
2. Sodium Bicarbonate ( for pH < 7.3 )
3. Ethanol infusion
4. Haemodialysis

= ** DEFINITIVE MANAGEMENT

Front 10

What are the indications for Haemodialysis in Methanol poisoning ?

Back 10

1. pH < 7.3 [ acidosis ]
2. Visual symptoms [ formic acid accumulation ]
3. Renal Failure
4. Deteriorating Vital signs / electrolytes
5. Level > 16 mmol/L

Front 11

Which of the following is incorrect regarding IVLE [ Intravenous Lipid Emulsion] Therapy ?
A. The initial bolus is 1 mL / kg over 1 minute
B. It is primarily indicated for "LAST" - local anaesthetic systemic toxicity e.g.. bupivicaine toxicity.
C. It comes as a 10% formulation in 50mL
D. It can be used as a rescue therapy in cardiac arrest with Propranolol overdose.

Back 11

C. IVLE = 20% formulation in 100 mL

Front 12

What are the main indications for IVLE

therapy ?

Back 12

1. LAST Local Anaesthetic Systemic toxicity

2. Rescue therapy for refractory cardiac

arrest in poisoning with :

a. Propranolol
b. TCA
c. Verapamil

Front 13

What are the indications for administration of methylene blue ?

Back 13

1. Symptomatic drug-induced

methaemoglobinaemia
( hypoxaemia with chest pain / breathlessness / confusion )
or
MetHb Levels > 20% ( "Consider")

Front 14

Which of the following drug toxicity -antidote

relationship is incorrect ?
A. Sulphonylureas = Octreotide
B. Dapsone = methylene blue
C. Pralidoxime = organophosphates
D. Pyridoxine = lead

Back 14

D Pyridoxine = Isoniazid

Lead =>

1. Sodium calcium edetate IV chelator

2. Succimer (DMSA) - oral chelator

Front 15

Which of the following drug toxicity - antidote

relationships is incorrect ?
A. Physostigmine - anticholinergic syndrome
B. Sodium thiosulfate = cyanide
C. Pyridoxine = isoniazid
D. Sodium calcium edetate = iron

Back 15

D. Iron = Desferrioxamine

Sodium calcium edetate = Lead

Front 16

In regards to Physostigmine in Anticholinergic Syndrome, which of the following is incorrect ?
A. The dose is 10 mg as slow IV push over 5 minutes- repeatable every 10 minutes.
B. It is indicated for Central anticholinergic agitated delirium-not

controlled with BZD.
C. It is a acetylcholinesterase inhibitor
D. It can be used for isolated anticholinergic poisoning :

eg. benztropine / atropine.

Back 16

A. Physostigmine = 1 mg push over 5 minutes
repeatable every 10 minutes until desired clinical effect observed.

Front 17

In regards to Activated charcoal, which of the

following is incorrect?
A. It does not adsorb alcohols, metals and corrosives.
B. Vomiting occurs in 30% of administered doses.
C. The dosing is 1 mg/kg orally.
D. It provides an enormous surface area for drug adsorption.

Back 17

C. Activated Charcoal = 1 G / kg -maximum 50 Grams.

Front 18

List the agents not adsorbed by Charcoal.

Back 18

1. Alcohol /Hydrocarbons
- Ethanol /methanol / ethylene glycol

/ isopropyl alcohol
2. Metals Lithium / Iron / Lead / Mercury
Arsenic / Potassium
3. Corrosives (Acids and Alkalis)

Front 19

Which is incorrect regarding Multidose

Activated Charcoal (MDAC) ?

A. After the initial dose, subsequent dosing is 0.5 G/kg every 4 hours.
B. Therapy is usually for 6 hours total.
C. Absent bowel sounds / Ileus / bowel obstruction is a contraindication.
D. MDAC enhances drug elimination via 2 main pathways.

Back 19

A. Dosing is 0.5 G/kg every 2 hours.

D : 2 pathways are :
1. Gastrointestinal dialysis
2. Interruption of enterohepatic circulation

Front 20

Which is a desired Pharmacokinetic feature of a drug that would benefit from MDAC ?

A. High Vd
B. High protein binding.
C. Lipid soluble
D. Large molecule.

Back 20

C.

A = Small Vd
B = low protein binding
D = small molecule

Front 21

List the drugs suitable for Enhanced Elimination via Multidose Activated Charcoal (MDAC) .

Back 21

" The ines and the ones"....
Carbamazepine
Theophylline
Quinine
Dapsone
Phenobarbitone
plus :
- phenytoin / Piroxicam / Amanita / Aspirin

Front 22

In regards to Vitamin K, which of the following is incorrect?
A. It is not contraindicated in pregnancy.
B. When giving oral vitamin K for warfarin reversal, the liquid injectable formulation is better absorbed than the tablets.
C. Anaphylaxis is rare.
D. It is indicated in Paediatric acute rodenticide ingestion.

Back 22

D. Single unintentional acute ingestion of an

anticoagulant rodenticide by a child does not

involve a sufficient dose to cause

anticoagulation.

Front 23

What are the toxicological indications for

administration of Vitamin K ?

Back 23

1. Therapeutic over-warfarinisation
2. Intentional warfarin overdose
3. Ingestion of long-acting anticoagulant

rodenticides ( brodifacoum)

Front 24

What are the dosages and administration

methods for Vitamin K in Warfarinised

patients with bleeding ?
(MJA 2013)

Back 24

INR > 1.5 with Life-threatening bleeding :
1. Vitamin K 5-10 mg IV
2. Prothrombinex 50 Units / kg IV
3. Fresh Frozen Plasma (FFP) 150-300 mL

INR > 2,0 with Clinically significant bleeding :
1. Vitamin K 5-10 mg IV
2. Prothrombinex 35-50 Units / kg IV

Any INR with Bleeding :
1. Vitamin K 1mg IV
(if bleeding risk high ) - "HAS BLED"

Front 25

Antidote for Amphetamine toxicity?

Back 25

Benzodiazepines

(Consider Dantrolene)

Front 26

Antidote for Bupivicaine toxicity ?

Back 26

1. Intralipid (IVLE therapy)

[ NaHCO3 for Na channel toxicity ]

Front 27

Antidote (s) for Cholinergics - Organophosphate poisoning ?

Back 27

1. Atropine

2. Pralidoxime

Front 28

Ethylene Glycol Tx options ?

Back 28

1. Ethanol

2. Fomepizole

3. Haemodialysis

4. Thiamine

5. Pyridoxine

Front 29

Systemic Fluorosis Tx

( Hydrofluoric acid toxicity) ?

Back 29

1. Calcium gluconate

2. Magnesium

Front 30

Lead toxicity Tx ?

Back 30

Chelation Therapy

1. IV chelator : Sodium Calcium edetate

2. Oral chelator : Succimer (DMSA)

Front 31

Methotrexate Toxicity Tx?

Back 31

Folinic acid

Front 32

Neuroleptic Malignant Syndrome (NMS)

Pharmacotherapy options?

Back 32

1. Bromocriptine: Dopamine agonist

2. Amantadine

3. Dantrolene

Front 33

Serotonin Syndrome Pharmacotherapy

options?

Back 33

1. Cyproheptadine

2. Benzodiazepines

Front 34

Valproate Toxicity pharmacotherapy options ?

Back 34

There are no antidotes for Valproate toxicity

1. Charcoal ( SDAC Time 0 and 4 hours )

2. Haemodialysis (HD)

• L- Carnitine [ hyperammonaemia ] **
  
• Naloxone
  

** Not currently recommended **