Antabuse and acetaldehyde

Question

An alcoholic can be treated with Antabuse. This drug causes the accumulation of acetaldehyde, an alcohol byproduct, resulting in chest pains, headaches, vomiting, anxiety, and other symptoms, causing the patient to cease alcohol consumption. Acetaldehyde, is normally degraded by the enzyme aldehyde oxidase. The Antabuse molecule resembles acetaldehyde. Use your knowledge of enzymes to speculate as to how the drug may work.

Answer 1

Disulfiram irreversibly binds to the enzyme aldehyde dehydrogenase preventing the conversion (oxidation) of acetaldehyde into acetate. It is able to bind to the enzyme's active site because it closely resembles acetaldehyde. Normally ethanol is converted into acetaldehyde by alcohol dehydrogenase. Acetaldehyde is then oxidized to acetate by aldehyde dehydrogenase. With aldehyde dehydrogenase inhibited, acetaldehyde concentrations increase in the blood leading to the very unpleasant symptoms such as flushing, intense, throbbing headache, dizziness, sweating, and vomiting.