1/21/25, 7:54 PM Lecturer of pharmacology and toxicology
Toxicology MCQs
1.Regarding Iron overdoses which is true?
a) 95% of ingested tablets are seen on plain x-ray?
b) Large overdose will produce a metabolic acidosis with a normal anion gap
c) Charcoal is the recommended method of GIT decontamination in the first hour
d) desferrioxamine when given to a severe OD will produce rose coloured urine
e) has no local GIT irritating effects
2.Regarding arrythmias secondary to overdose which is false?
a) HCO3 is the drug of choice for arrythmias caused by tricyclic antidepressants
b) In arrythmias secondary to digoxin OD cardioversion is recommended
c) Arrythmias associated with cocaine may respond to benzodiazapines
d) Quinine in OD produces 1A antiarrythmic effects
e) Dextropropoxyphene increases the QRS and QT segments in OD
3.With regards to acute cyanide OD which is false?
a) ferric ion of cytochrome oxidase system is bound, ceasing oxidative phosphorylation and aerobic
metabolism
b) less than half the population will recognise the bitter almond odour
c) Cobalt EDTA is a safe and non toxic method of treating overdose
d) Hydroxycobalamin is a safe and non toxic method of treating overdose
e) A cyanide level is rarely useful in management of acute OD
4.Which is false?
a) at pH 7.4 salicylic acid is in the unionized form
b) patients are often hyperthermic
c) when alkalinizing the urine, serum K+ replacement may be required
d) haemodialysis is of benefit
e) a serum salicilate level of 2.0 at 6 hours is sufficient for medical discharge.
5.With regard to paracetamol OD which is false?
a) children are relatively resistant to toxicity because the cP450 system is under developed
b) in “at risk” patients the threshold level for Nacetylcysteine should be halved
c) acute alcohol coingestion in a person that does not usually drink is reason to lower the treatment
threshold for paracetamol OD
d) if a patient presents at 8-24 hours after OD, Nacetylcysteine should be commenced pending the results
e) the Rumack Mathews nomogram is not helpful in multiple ingestions at different times over 24 hours.
6.A learning exercise: All of the below statements are true regarding GHB (gamma hydroxybutyrate)
a) is a psychoactive drug of abuse
b) it has been used clinically to treat narcolepsy, as an anaesthetic aents, to treat alcohol withdrawl and in
body building
c) it has a very short elimination half life (30 mins) and thus may not be detectable in a urine sample taken
after delay of several hours
d) has been involved in two separate group presentations to Gold Coast hospital where 11 of the 14 pts
needed intubation
e) usually taken with a coingestant, probably not recognized by the pt
7.With regards to management of Warfarin toxicity which is false?
a) any major bleeding should be managed with 5-10 mg IV Vit K and FFP
b) the onset of action of IV Vit K is 1-3 hours
c) with an INR of 13, if a patient has minor or no bleeding then FFP is still warranted
d) If a pt has an INR of 13 with minimal bleeding, an appropriate IV dose of Vit K would be 1-2 mg IV
e) If Vit K is given for a toxic INR with no major bleeding then the INR should be checked in 6-12 hours,
and the warfarin withheld for 1-2 days.
about:blank 1/14
, 1/21/25, 7:54 PM Lecturer of pharmacology and toxicology
8.Lithium toxicity. Which is false?
a) Toxicity associated with chronic use occurs at lower serum levels
b) In a non user an acute overdose may not be symptomatic until the serum level is greater than 3
c) Introduction of thiazide diuretics or NSAID’s may cause a pt usually in the therapeutic range to become
toxic
d) Most effects of acute OD are neurological
e) Appropriate management of an acute OD could include charcoal, IV fluids and haemodialysis
9.Which is the wrong mechanism of action for the listed drug/toxin?
a) Colcichine: binds to intracellular tubulin preventing cell mitosis
b) Amanita phalloides: impairs DNA synthesis
c) Strychnine: inhibits glycine in the spinal cord
d) Isoniazid: reduces folate activity
e) Iron: disrupts oxidative phosphorylation
f) Paraquat: generates oxygen free radicals
10.With regards to organophosphates and carbamates which is false
a) both inactivate acetyl cholinesterase
b) both cause an acute cholinergic syndrome
c) both respond to treatment with atropine
d) both respond to treatment with pralidoxime
e) if there is associated CNS signs and muscle weakness the cause is likely to be organophosphates.
11.Which is false about the blue-ringed octopus?
a) it has a toxin similar to tetrodotoxin, which causes paralysis
b) treatment consists of antivenom administration and cardiovascular support
c) spontaneous ventilation usually recurs after 12 hours
d) despite needing CPR or assisted ventilation the patient is aware and conscious
e) first aid consists of compression bandaging
12.Which is false with regard to the box jelly-fish?
a) it has a vaccine which can be administer i.v. or i.m., though i.v is more effective
b) the tentacles may extend up to 3 metres and produce an extremely painful sting
c) vinegar is used for its symptomatic relief only
d) its toxin causes neuromuscular paralysis, cardiotoxicity and dermatonecrosis
e) compression bandaging is recommended
13.Which is false?
a) first aid of all marine ‘spine’ wounds consists of administration of hot water
b) the stone fish has an antivenom which is available i.m.
c) in Australia there are no reported deaths due to stone fish
d) fatalities have been reported due to cone shell envenomation for which no antivenom is available
e) most of the documented stingray fatalities are secondary to their toxin
14.With regard to snake bite which is true?
a) there is no specific seasnake antivenom
b) tiger and brown snakes are more less likely to cause paralysis than black snake
c) in Victoria the only two venomous snakes are the tiapan and the brown snake
d) the dose of antivenom needed for tiger snake envenomation is usually one vial
e) the antivenom sould be diluted 1in 10 in Nornal Saline and given over half and hour
about:blank 2/14
Toxicology MCQs
1.Regarding Iron overdoses which is true?
a) 95% of ingested tablets are seen on plain x-ray?
b) Large overdose will produce a metabolic acidosis with a normal anion gap
c) Charcoal is the recommended method of GIT decontamination in the first hour
d) desferrioxamine when given to a severe OD will produce rose coloured urine
e) has no local GIT irritating effects
2.Regarding arrythmias secondary to overdose which is false?
a) HCO3 is the drug of choice for arrythmias caused by tricyclic antidepressants
b) In arrythmias secondary to digoxin OD cardioversion is recommended
c) Arrythmias associated with cocaine may respond to benzodiazapines
d) Quinine in OD produces 1A antiarrythmic effects
e) Dextropropoxyphene increases the QRS and QT segments in OD
3.With regards to acute cyanide OD which is false?
a) ferric ion of cytochrome oxidase system is bound, ceasing oxidative phosphorylation and aerobic
metabolism
b) less than half the population will recognise the bitter almond odour
c) Cobalt EDTA is a safe and non toxic method of treating overdose
d) Hydroxycobalamin is a safe and non toxic method of treating overdose
e) A cyanide level is rarely useful in management of acute OD
4.Which is false?
a) at pH 7.4 salicylic acid is in the unionized form
b) patients are often hyperthermic
c) when alkalinizing the urine, serum K+ replacement may be required
d) haemodialysis is of benefit
e) a serum salicilate level of 2.0 at 6 hours is sufficient for medical discharge.
5.With regard to paracetamol OD which is false?
a) children are relatively resistant to toxicity because the cP450 system is under developed
b) in “at risk” patients the threshold level for Nacetylcysteine should be halved
c) acute alcohol coingestion in a person that does not usually drink is reason to lower the treatment
threshold for paracetamol OD
d) if a patient presents at 8-24 hours after OD, Nacetylcysteine should be commenced pending the results
e) the Rumack Mathews nomogram is not helpful in multiple ingestions at different times over 24 hours.
6.A learning exercise: All of the below statements are true regarding GHB (gamma hydroxybutyrate)
a) is a psychoactive drug of abuse
b) it has been used clinically to treat narcolepsy, as an anaesthetic aents, to treat alcohol withdrawl and in
body building
c) it has a very short elimination half life (30 mins) and thus may not be detectable in a urine sample taken
after delay of several hours
d) has been involved in two separate group presentations to Gold Coast hospital where 11 of the 14 pts
needed intubation
e) usually taken with a coingestant, probably not recognized by the pt
7.With regards to management of Warfarin toxicity which is false?
a) any major bleeding should be managed with 5-10 mg IV Vit K and FFP
b) the onset of action of IV Vit K is 1-3 hours
c) with an INR of 13, if a patient has minor or no bleeding then FFP is still warranted
d) If a pt has an INR of 13 with minimal bleeding, an appropriate IV dose of Vit K would be 1-2 mg IV
e) If Vit K is given for a toxic INR with no major bleeding then the INR should be checked in 6-12 hours,
and the warfarin withheld for 1-2 days.
about:blank 1/14
, 1/21/25, 7:54 PM Lecturer of pharmacology and toxicology
8.Lithium toxicity. Which is false?
a) Toxicity associated with chronic use occurs at lower serum levels
b) In a non user an acute overdose may not be symptomatic until the serum level is greater than 3
c) Introduction of thiazide diuretics or NSAID’s may cause a pt usually in the therapeutic range to become
toxic
d) Most effects of acute OD are neurological
e) Appropriate management of an acute OD could include charcoal, IV fluids and haemodialysis
9.Which is the wrong mechanism of action for the listed drug/toxin?
a) Colcichine: binds to intracellular tubulin preventing cell mitosis
b) Amanita phalloides: impairs DNA synthesis
c) Strychnine: inhibits glycine in the spinal cord
d) Isoniazid: reduces folate activity
e) Iron: disrupts oxidative phosphorylation
f) Paraquat: generates oxygen free radicals
10.With regards to organophosphates and carbamates which is false
a) both inactivate acetyl cholinesterase
b) both cause an acute cholinergic syndrome
c) both respond to treatment with atropine
d) both respond to treatment with pralidoxime
e) if there is associated CNS signs and muscle weakness the cause is likely to be organophosphates.
11.Which is false about the blue-ringed octopus?
a) it has a toxin similar to tetrodotoxin, which causes paralysis
b) treatment consists of antivenom administration and cardiovascular support
c) spontaneous ventilation usually recurs after 12 hours
d) despite needing CPR or assisted ventilation the patient is aware and conscious
e) first aid consists of compression bandaging
12.Which is false with regard to the box jelly-fish?
a) it has a vaccine which can be administer i.v. or i.m., though i.v is more effective
b) the tentacles may extend up to 3 metres and produce an extremely painful sting
c) vinegar is used for its symptomatic relief only
d) its toxin causes neuromuscular paralysis, cardiotoxicity and dermatonecrosis
e) compression bandaging is recommended
13.Which is false?
a) first aid of all marine ‘spine’ wounds consists of administration of hot water
b) the stone fish has an antivenom which is available i.m.
c) in Australia there are no reported deaths due to stone fish
d) fatalities have been reported due to cone shell envenomation for which no antivenom is available
e) most of the documented stingray fatalities are secondary to their toxin
14.With regard to snake bite which is true?
a) there is no specific seasnake antivenom
b) tiger and brown snakes are more less likely to cause paralysis than black snake
c) in Victoria the only two venomous snakes are the tiapan and the brown snake
d) the dose of antivenom needed for tiger snake envenomation is usually one vial
e) the antivenom sould be diluted 1in 10 in Nornal Saline and given over half and hour
about:blank 2/14
