Acetaminophen inhibits prostaglandin synthesis, resulting in analgesic and antipyretic effects, but it is not considered which type of drug?

• A. Stimulates histamine release; broad-spectrum anti-inflammatory
• B. Inhibits prostaglandin synthesis; not an NSAID
• C. Inhibits COX-2 only; has anti-inflammatory action
• D. Blocks opioid receptors; has strong anti-inflammatory action

Answer: (B)

The main idea is that acetaminophen reduces pain and fever by inhibiting prostaglandin synthesis in the brain, but it does not produce meaningful anti-inflammatory effects in peripheral tissues. Because its action is central rather than peripheral, it lacks the anti-inflammatory properties that classify NSAIDs. That’s why the description “inhibits prostaglandin synthesis; not an NSAID” fits best.

In other words, NSAIDs reduce inflammation in addition to pain and fever by blocking prostaglandin production outside the central nervous system, whereas acetaminophen’s limited peripheral activity means it provides analgesia and antipyresis without true anti-inflammatory effects. The other options describe mechanisms that don’t match acetaminophen: stimulating histamine release with broad anti-inflammatory action isn’t how it works; selectively inhibiting COX-2 with anti-inflammatory action would imply an NSAID with peripheral effects; and blocking opioid receptors with strong anti-inflammatory action isn’t correct for acetaminophen.