Ethyl alcohol is given in cases of ethylene glycol or methanol poisoning because it blocks the formation of the toxic metabolites.

• A. Helps sedate patients
• B. Increases the metabolism of toxic alcohols
• C. Blocks the formation of the toxic metabolites of ethylene glycol and methanol
• D. Increases renal clearance of the toxic alcohols

Answer: (C)

The main idea is that ethanol works by blocking the formation of toxic metabolites. It does this by competitively inhibiting alcohol dehydrogenase, the enzyme that converts methanol and ethylene glycol into harmful products like formaldehyde, formate, glycolic acid, and oxalate. By occupying the enzyme, ethanol slows or prevents these toxic metabolites from forming, reducing metabolic acidosis and organ injury while allowing the parent substances to be eliminated. The other options don’t fit because ethanol’s role here is not to sedate, not to increase the metabolism of the toxic alcohols, and not to boost renal clearance; its therapeutic effect comes from preventing toxic metabolite formation through enzyme inhibition.