Disulfiram is prescribed to support abstinence in alcohol dependence. Its pharmacological mechanism is:
- A NMDA glutamate receptor antagonism
- B Competitive antagonism of mu-opioid receptors
- C Irreversible inhibition of aldehyde dehydrogenase ✓
- D Blockade of voltage-gated calcium channels containing alpha2delta subunits
Correct answer: C. Irreversible inhibition of aldehyde dehydrogenase
Explanation
Disulfiram irreversibly inhibits aldehyde dehydrogenase, so ethanol metabolism stops at acetaldehyde, whose accumulation causes flushing, headache, nausea, palpitations, and hypotension (the disulfiram ethanol reaction); this aversive consequence supports abstinence. Mu-receptor antagonism describes naltrexone, NMDA antagonism relates to ketamine and memantine, and alpha2delta blockade is gabapentin's mechanism, used off-label in alcohol withdrawal. Because enzyme inhibition is irreversible, sensitivity persists up to about two weeks after stopping the drug.
Reference: Katzung's Basic and Clinical Pharmacology, 16th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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