In the management of toxicity caused by ingestion of methanol in wood spirits, which one of the following statements is most accurate?
**Core Concept**
Methanol toxicity is a serious condition that occurs when methanol is ingested, leading to the accumulation of its metabolites, formic acid and formaldehyde, which cause cellular damage and tissue necrosis. The management of methanol toxicity involves the use of antidotes to prevent the formation of these toxic metabolites.
**Why the Correct Answer is Right**
The correct treatment for methanol toxicity involves the administration of fomepizole, a selective and reversible inhibitor of alcohol dehydrogenase (ADH), the enzyme responsible for the conversion of methanol to formic acid. By inhibiting ADH, fomepizole prevents the formation of formic acid and formaldehyde, thereby reducing the severity of methanol toxicity. This is in contrast to ethanol, which is also an inhibitor of ADH but is less selective and can have adverse effects at high doses.
**Why Each Wrong Option is Incorrect**
**Option A:** Hemodialysis is a supportive measure that can be used to remove methanol and its metabolites from the body, but it does not address the underlying cause of toxicity. It is not a definitive treatment for methanol toxicity.
**Option B:** Activated charcoal may be used to absorb methanol in the gastrointestinal tract, but it is not effective in preventing the conversion of methanol to its toxic metabolites.
**Option C:** Ethanol can inhibit ADH, but it is less selective than fomepizole and can have adverse effects at high doses. Additionally, ethanol does not address the underlying cause of toxicity and is not a definitive treatment.
**Clinical Pearl / High-Yield Fact**
Fomepizole is a highly effective antidote for methanol toxicity, but it must be used promptly after ingestion to prevent the formation of toxic metabolites. Delayed treatment can lead to severe and irreversible damage.
**Correct Answer: C. Ethanol can inhibit ADH, but it is less selective than fomepizole and can have adverse effects at high doses. Additionally, ethanol does not address the underlying cause of toxicity and is not a definitive treatment.