Toxicology

Question 1

Fomepizole

Answer 1

Competitive inhibitor of alcohol dehydrogenase.
Preferred antidote for overdoses of methanol or ethylene glycol.

Question 2

Methanol intoxication

Answer 2

Is metabolized by alcohol dehydrogenase (ADH) to formaldehyde, which is then converted to formic acid by aldehyde dehydrogenase.
Formic acid is toxic to the optic nerve = blindness with as little as 30 mL ingested. Early formation of formic acid leads to metabolic acidosis.

Question 3

TCA overdose

Answer 3

Altered mental status, dilated pupils, and wide QRS complex on ECG.
TCAs have anticholinergic properties: dry/flushed skin, decreased bowel sounds, constipation, hyperreflexia, and dilated pupils.
treatment: sodium bicarbonate.

Question 4

Iron intoxication

Answer 4

Abdominal pain, bloody emesis, metabolic acidosis, and radiopaque tablets on radiography.
Symptoms can begin within 30-60 minutes following ingestion and escalate to circulatory shock after 48 hours.
Free iron’s toxicity to the vasculature, release of serotonin and histamine: injury to mitochondria, lipid peroxidation, and the uncoupling of oxidative phosphorylation. The treatment: stabilize the patient and administer deferoxamine.

Question 5

Vitamin D toxicity

Answer 5

Polyuria, polydipsia, nocturia, hypercalcemia, and hypercalciuria. Abdominal pain, nausea, vomiting, and occasionally pancreatitis can be seen.

Question 6

Osmolar gap

Answer 6

is an indication of unmeasured solute in the blood

Question 7

In a patient who presents with symptoms of alcohol toxicity, an elevated anion gap and osmolar gap + calcium oxalate crystals in their urine strongly suggests?

Answer 7

ethylene glycol toxicity