Disulfiram is used as an aversive agent in chronic alcoholism. The biochemical basis of the disulfiram-ethanol reaction is:
- A Inhibition of alcohol dehydrogenase, blocking ethanol conversion to acetaldehyde
- B Induction of CYP2E1, accelerating acetaldehyde formation
- C Inhibition of aldehyde dehydrogenase, causing acetaldehyde accumulation ✓
- D Blockade of mu-opioid receptors, preventing endorphin-mediated reward
Correct answer: C. Inhibition of aldehyde dehydrogenase, causing acetaldehyde accumulation
Explanation
Disulfiram irreversibly inhibits aldehyde dehydrogenase, so ethanol metabolism stops at acetaldehyde, whose accumulation causes flushing, throbbing headache, nausea, vomiting, hypotension and palpitations within minutes of drinking. Alcohol dehydrogenase is inhibited by fomepizole, which is used in methanol and ethylene glycol poisoning, making option A the classic tempting distractor. CYP2E1 induction increases tolerance rather than aversion.
Reference: Katzung's Basic and Clinical Pharmacology, 16th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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