FPGEE Toxicology 2

Question 1

Which antidote is used to treat cyanide poisoning by acting as a methemoglobin-forming agent?

Accepted Answer

Amyl nitrite followed by sodium nitrite

Answer

Amyl nitrite and sodium nitrite generate methemoglobin, which competes with cytochrome oxidase for cyanide, while sodium thiosulfate converts cyanide to thiocyanate.

Question 2

A patient presents with miosis, bradycardia, excessive secretions, and muscle fasciculations after a suspected pesticide exposure. What is the most likely toxidrome?

Accepted Answer

Cholinergic

Answer

Organophosphate or carbamate pesticides inhibit acetylcholinesterase, causing a cholinergic toxidrome with SLUDGE/DUMBELS symptoms including miosis, bradycardia, and secretions.

Question 3

The Rumack-Matthew nomogram is used to guide treatment decisions in which type of poisoning?

Accepted Answer

Acetaminophen overdose

Answer

The Rumack-Matthew nomogram plots serum acetaminophen concentration against time post-ingestion to predict hepatotoxicity risk and the need for N-acetylcysteine.

Question 4

Which heavy metal toxicity is classically associated with Mees' lines on fingernails, peripheral neuropathy, and garlic odor on the breath?

Accepted Answer

Arsenic

Answer

Chronic arsenic poisoning causes Mees' lines (transverse white lines on nails), peripheral neuropathy, and a characteristic garlic-like breath odor.

Question 5

What is the mechanism by which iron causes toxicity in overdose?

Accepted Answer

Free radical generation via the Fenton reaction

Answer

Excess iron catalyzes the Fenton reaction, converting hydrogen peroxide to hydroxyl radicals that cause lipid peroxidation and mitochondrial dysfunction.

FPGEE Exam Practice Test

FPGEE Exam Practice Test

FPGEE Toxicology 2