Ibuprofen acts on:
**Core Concept**
Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) that acts by inhibiting the production of prostaglandins, which are key mediators of inflammation, pain, and fever. This action is primarily achieved through the inhibition of cyclooxygenase (COX) enzymes.
**Why the Correct Answer is Right**
Ibuprofen is a non-selective COX inhibitor, meaning it blocks both COX-1 and COX-2 enzymes, which are responsible for the conversion of arachidonic acid to prostaglandin H2 (PGH2). This PGH2 is then converted to various prostaglandins, including PGE2, which mediates inflammation and pain. By inhibiting COX enzymes, ibuprofen reduces the production of these prostaglandins, thereby exerting its anti-inflammatory and analgesic effects.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not relevant to the mechanism of action of ibuprofen.
**Option B:** This option is incorrect as ibuprofen does not primarily act on adrenergic receptors.
**Option C:** This option is incorrect as ibuprofen does not primarily act on opioid receptors.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that NSAIDs like ibuprofen can cause gastrointestinal irritation and bleeding due to their COX-1 inhibitory effects, which are responsible for protecting the stomach lining. Patients taking NSAIDs should be monitored for signs of gastrointestinal toxicity.
**Correct Answer: C. COX enzymes**