Tag Archives: mcq

MCQs On Forensic Toxicology

1. Which of the following is NOT a side effect of Digoxin toxicity?

A. Bradycardia
B. Yellow vision changes
C. Scooping of the T segment on ECG
D. Hypokalemia

2. Which information can be obtained from an acute toxicity study?

A. Median toxic dose (TD50)
B. Median lethal dose (LD50)
C. No Observed Adverse Effect Level (NOEL)
D. Target organ
E. All of the above

3. A particular dose of a substance X is minimal toxic to animal. Substance Y is also minimal toxic to the animals at the same dose, but when both the substances are administered together they show the toxicity several orders of magnitude higher than compared with individual administrations. This is an example of:

A. Potentiation
B. Synergism
C. Additivity
D. Acute Toxicity
E. Agonism

4. Which of the following chelating agents is recommended for acute Lead poisoning with signs of encephalopathy?

A. Succimer
B. Penicillamine
C. Dimercaprol
D. Calcium EDTA
E. Dimercaprol + Calcium EDTA

5. Which of the following dermatologic findings and potential causes is INCORRECT?

A. Cyanosis- Methemoglobinemia
B. Erythroderma – Boric Acid
C. Pallor – Carbon Monoxide
D. Jaundice – Hypercarotinemia (excess carrot intake)

6. All of the following symptoms can occur with Ciguatera poisoning EXCEPT…

A. Myalgias
B. Flushing
C. Metallic taste
D. Reversal of temperature sensation

7. Which of the following is true with regard to Acetaminophen toxicity?

A. The Rumack-Matthew Normogram may be used for both acute and chronic ingestions.
B. The APAP level should ideally be checked within 1-4 hours of ingestion.
C. The Rumack-Matthew Normogram applies for ingestions up to 48 hours post-ingestion.
D. N-Acetylcysteine (NAC) should be started within 8 hours of ingestion if an APAP level cannot be obtained.

8. All of the following are treatment options for toxic alcohol poisoning, EXCEPT…

A. Fomepizole
B. Hydroxocobalamin
C. Thiamine
D. Folic Acid

9. Which one of the following are the main targets of lead toxicity?

A. Liver and kidneys
B. Nervous system and hematopoietic system
C. Heart and lung
D. Bones and muscles

10. ‘Itai-itai’ disease is caused by______

A. Cadmium
B. Mercury
C. Lead
D. Copper


Answers with Explanation:

1. Answer: D.

Despite the number of patients who come in taking Digoxin, it is important to remember that this medication comes with a large range of side effects. Bradycardia (along with any of the other SLUDGE Toxidrome symptoms) is a common effect due to the Parasympathetic activity of Digoxin. (Note: This is also the reason it works as a second-line agent for rate control of Atrial Fibrillation.) Yellow, halo-like vision changes (think Van Gogh’s ‘Starry Night’) are a more rare, but classic finding.

2. Answer: E.

In an acute toxicity study any end point parameter such as death, brain damage, liver damage etc. can be used to obtain information regarding a particular toxicant.


References:

Wright RO et al. Methemoglobinemia: etiology, pharmacology, and clinical management. Ann Emerg Med. 1999 Nov;34(5):646-56.

Prescott LF, Illingworth RN, Critchley JA, et al. Intravenous N-acetylcysteine: the treatment of choice for paracetamol poisoning. BMJ. 1979 Nov 3;2(6198):1097-100.

Yeates PJ, Thomas SH. Effectiveness of delayed activated charcoal administration in simulated paracetamol (acetaminophen) overdose. Br J Clin Pharmacol. 2000 Jan;49(1):11-4.

Sivilotti ML, Burns MJ, McMartin KE, et al. Toxicokinetics of ethylene glycol during fomepizole therapy: implications for management. For the Methylpyrazole for Toxic Alcohols Study Group. Ann Emerg Med. 2000 Aug;36(2):114-25.

Brent J. Fomepizole for ethylene glycol and methanol poisoning. N Engl J Med. 2009 May 21;360(21):2216-23.

Lheureux P, Penaloza A, Gris M. Pyridoxine in clinical toxicology: a review. Eur J Emerg Med. 2005 Apr;12(2):78-85.