DrugMechanism of ActionProstaglandins/Thromboxanes AffectedPhysiological Effects
AspirinIrreversible inhibition of COX-1 and COX-2, blocking prostaglandin and thromboxane synthesis.↓ PGE2: Less pain, fever, and inflammation.
↓ PGD2: Reduced allergic responses, bronchoconstriction.
↓ PGI2: Reduced vasodilation, platelet inhibition.
↓ TXA2: Decreased platelet aggregation (irreversible).		- Anti-inflammatory, analgesic, and antipyretic.
- Cardioprotective at low doses (via TXA2 inhibition).
Ibuprofen (Advil)Reversible inhibition of COX-1 and COX-2, blocking arachidonic acid conversion into prostaglandins.↓ PGE2: Pain, fever, and inflammation relief.
↓ PGI2: Reduced vasodilation.
↓ TXA2: Reduced platelet aggregation (reversible).		- Anti-inflammatory, analgesic, and antipyretic.
- Shorter duration of platelet effects than aspirin.
Naproxen (Aleve)Reversible inhibition of COX-1 and COX-2, similar to ibuprofen, but with a longer half-life.↓ PGE2, PGI2, PGD2, TXA2 (similar to ibuprofen).- Longer-lasting pain and inflammation relief.
Acetaminophen (Tylenol)Weak COX inhibition, primarily in the CNS. Possible selective COX-2 inhibition in the brain.↓ PGE2 (CNS only): Reduced pain and fever perception.- Analgesic and antipyretic.
- Minimal anti-inflammatory effects.
Celecoxib (Celebrex)Selective COX-2 inhibition, reducing prostaglandins associated with inflammation while sparing COX-1.↓ PGE2, PGI2: Reduced inflammation and pain.- Anti-inflammatory and analgesic.
- Lower gastrointestinal side effects than non-selective NSAIDs.
Diclofenac (Voltaren)Reversible inhibition of COX-1 and COX-2 with higher potency.↓ PGE2, PGI2, TXA2, PGD2: Strong anti-inflammatory effects.- Potent anti-inflammatory and analgesic effects, especially for joint and muscle pain.
Aspirin + Caffeine (Excedrin)Combination of aspirin, acetaminophen, and caffeine.↓ PGE2 (CNS + periphery): Combined pain and fever relief.
↓ TXA2: Anti-clotting effects.		- Effective for headaches and migraines.
- Caffeine enhances prostaglandin inhibition effects.