What is the mechanism of action of ibuprofen?

Ibuprofen functions primarily as a reversible inhibitor of cyclooxygenase (COX) enzymes. The COX enzymes are crucial for synthesizing prostaglandins, which are lipid compounds that play a significant role in mediating inflammation, pain, and fever. By inhibiting these enzymes, ibuprofen effectively reduces the production of prostaglandins, leading to its anti-inflammatory, analgesic, and antipyretic effects. This mechanism allows it to alleviate pain and reduce inflammation in various conditions, such as arthritis, menstrual cramps, and headaches.

In contrast, the other mechanisms listed relate to different drug classes and pathways. For instance, xanthine oxidase inhibition is associated with medications used to treat gout, while 5α reductase inhibition pertains to the treatment of conditions like benign prostatic hyperplasia and androgenetic alopecia. Carbonic anhydrase inhibitors are primarily used for conditions like glaucoma or to promote diuresis. Therefore, the unique action of ibuprofen as a reversible COX inhibitor sets it apart from the other choices.