Fomepizole is a competitive inhibitor of which enzyme?

Fomepizole is a specific competitive inhibitor of alcohol dehydrogenase, which is the enzyme responsible for the conversion of ethanol and other alcohols into their respective aldehydes. This inhibition is particularly relevant in the treatment of methanol or ethylene glycol poisoning, where alcohol dehydrogenase would normally convert these toxic substances into dangerous metabolites. By inhibiting this enzyme, fomepizole effectively slows down the metabolism of methanol or ethylene glycol, allowing these substances to be excreted unchanged by the kidneys and reducing the risk of serious toxicity and harmful effects.

Other options like cytochrome P450 involve a range of metabolic processes and are not specifically targeted by fomepizole. Aldose reductase is involved in the conversion of glucose to sorbitol and does not play a direct role in alcohol metabolism. Glutamate decarboxylase is an enzyme important in the metabolism of the neurotransmitter GABA, unrelated to alcohol dehydrogenase. Thus, the role of fomepizole as a competitive inhibitor of alcohol dehydrogenase is central to its therapeutic use in managing certain types of alcohol poisoning.