Acetaminophen MOA is:

Acetaminophen MOA is:

• A. Inhibits prostaglandin synthesis in CNS; COX-2 inhibition; minimal peripheral anti-inflammatory effects
• B. Blocks NMDA receptors
• C. Inhibits 5-LOX
• D. Irreversibly inhibits COX enzymes

Answer: (A)

Acetaminophen works mainly in the brain. It lowers fever and relieves pain by inhibiting prostaglandin synthesis in the central nervous system, effectively dampening the hypothalamic fever response and CNS pain signaling. This central, reversible COX inhibition gives strong antipyretic and analgesic effects but only minimal peripheral anti-inflammatory action, which is why it does not significantly reduce inflammation in peripheral tissues. The other mechanisms listed don’t match acetaminophen: blocking NMDA receptors is the domain of drugs like ketamine, 5-LOX inhibition targets leukotriene pathways, and irreversible COX inhibition describes aspirin, not acetaminophen.

Acetaminophen works mainly in the brain. It lowers fever and relieves pain by inhibiting prostaglandin synthesis in the central nervous system, effectively dampening the hypothalamic fever response and CNS pain signaling. This central, reversible COX inhibition gives strong antipyretic and analgesic effects but only minimal peripheral anti-inflammatory action, which is why it does not significantly reduce inflammation in peripheral tissues. The other mechanisms listed don’t match acetaminophen: blocking NMDA receptors is the domain of drugs like ketamine, 5-LOX inhibition targets leukotriene pathways, and irreversible COX inhibition describes aspirin, not acetaminophen.