What does acetazolamide inhibit?

Acetazolamide primarily inhibits carbonic anhydrase, an enzyme that facilitates the reversible reaction of carbon dioxide and water to form carbonic acid, which dissociates into bicarbonate and protons. By inhibiting this enzyme, acetazolamide decreases the production of bicarbonate in the proximal convoluted tubule of the kidney, leading to increased bicarbonate excretion in urine. This mechanism effectively produces a mild diuretic effect, as it disrupts the normal bicarbonate reabsorption process. Additionally, carbonic anhydrase inhibition has implications in managing certain conditions such as glaucoma, altitude sickness, and some forms of metabolic alkalosis.

The other options listed pertain to different pharmacological targets. Reversible COX enzymes are involved in prostaglandin synthesis, 5α reductase is related to testosterone metabolism, and xanthine oxidase plays a role in purine metabolism. Each of these enzymes has distinct roles in various physiological processes and are targeted by other medications, but they are not the primary action of acetazolamide.