Acetylcysteine (Mucomyst) is the antidote for overdose of which substance?

Acetylcysteine (Mucomyst) is the antidote for overdose of which substance?

• A. Acetaminophen
• B. Aspirin
• C. Methanol
• D. Ethylene glycol

Answer: (A)

Acetylcysteine replenishes glutathione, which is the body’s main defense against the toxic metabolite of acetaminophen, NAPQI. In an overdose, acetaminophen is converted to NAPQI, and if glutathione stores are depleted, NAPQI binds liver cells and causes injury. Acetylcysteine provides a sulfhydryl group that helps regenerate glutathione and also can directly conjugate with NAPQI, helping detoxify it and reduce liver damage. It’s most effective when given early after ingestion, but can still help even if some time has passed. This isn’t a treatment for overdoses of the other substances listed: those have different antidotes or management approaches—for example, methanol and ethylene glycol overdoses are treated with fomepizole or ethanol to inhibit their metabolism, and aspirin overdose is managed with supportive care and urine alkalinization or other measures as appropriate.

Acetylcysteine replenishes glutathione, which is the body’s main defense against the toxic metabolite of acetaminophen, NAPQI. In an overdose, acetaminophen is converted to NAPQI, and if glutathione stores are depleted, NAPQI binds liver cells and causes injury. Acetylcysteine provides a sulfhydryl group that helps regenerate glutathione and also can directly conjugate with NAPQI, helping detoxify it and reduce liver damage. It’s most effective when given early after ingestion, but can still help even if some time has passed.

This isn’t a treatment for overdoses of the other substances listed: those have different antidotes or management approaches—for example, methanol and ethylene glycol overdoses are treated with fomepizole or ethanol to inhibit their metabolism, and aspirin overdose is managed with supportive care and urine alkalinization or other measures as appropriate.