2H
5OH) serves as a competitive inhibitor to methanol (CH
3OH) and ethylene glycol ((CH2OH)2) for the enzyme alcohol dehydrogenase in the liver when present in large amounts. For this reason, ethanol is sometimes used as a means to treat or prevent toxicity following accidental ingestion of these chemicals.
Competitive inhibition is interruption of a chemical pathway owing to one chemical substance inhibiting the effect of another by competing with it for binding or bonding. Any metabolic or chemical messenger system can potentially be affected by this principle, but several classes of competitive inhibition are especially important in biochemistry and medicine, including the competitive form of enzyme inhibition, the competitive form of receptor antagonism, the competitive form of antimetabolite activity, and the competitive form of poisoning (which can include any of the aforementioned types).