This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pharmacokinetics, Subject name: Pharmacology
Disulphiram acts by competitive inhibition of which enzyme? 
Select and explain. 
A. Alcohol dehydrogenase, B. Aldehyde dehydrogenase, C. Alcohol carboxylase, D. Aldyhyde carboxylase
B: Aldehyde dehydrogenase
Answer: B: Aldehyde dehydrogenase 
Explanation: Ans. (b) Aldehyde dehydrogenaseRef KDT 6th ed. / 386EthanolAlcohol Dehydrogenase-------------------Acetaldehyde Aldehyde Dehydrogenase---------------------Acetate* Disulfiram is an anti-craving agent for alcoholics. It has been used as an aversion technique in alcoholics.* Disulfiram acts by inhibiting aldehyde dehydrogenase. If a person still takes alcohol while on disulfiram treatment, alcohol is metabolized as usual, but acetaldehyde accumulates.* This accumulation of acetaldehyde gives some distressing symptoms like flushing, burning sensation, throbbing headache, perspiration, dizziness, vomiting, confusion and circulatory collapse.* Therefore, it is recommended only for those alcoholics who are motivated and sincerely desire to leave the habit.* Drugs causing Disulfiram like reaction:# Metronidazole# Chlorpropamide# Cefoperazone# Cefotetan# Trimethorprim* Other drugs that decrease craving for alcohol and smoking: (remembered as NATO)# NALTREXONE# ACAMPROSATE# TOPIRAMATE# ONDANSETRONAlso Know* Drug which inhibit alcohol dehydrogenase - FOMEPIZOLE* Antidote for methanol poisoning: FOMEPIZOLE > ETHANOL* Antidote for ethelene glycol poisoning: FOMEPIZOLE