Mechanism of action of aspirin-like drugs

Semin Arthritis Rheum. 1997 Jun;26(6 Suppl 1):2-10. doi: 10.1016/s0049-0172(97)80046-7.


Nonsteroid antiinflammatory drugs (NSAIDs) or aspirin-like drugs act by inhibiting the activity of the cyclooxygenase (COX) enzyme. Two isoforms of COX exist, COX-1, which is constitutively expressed, and COX-2, which is an inducible isoform. Prostaglandins synthesized by the constitutively expressed COX-1 are implicated in the maintenance of normal physiological function and have a 'cytoprotective' action in the stomach. COX-2 expression is normally low but is induced by inflammatory stimuli and cytokines. It is thought that the antiinflammatory actions of NSAIDs are caused by the inhibition of COX-2, whereas the unwanted side effects, such as gastrointestinal and renal toxicity, are caused by the inhibition of the constitutively expressed COX-1. Individual NSAIDs show different selectivities against the COX-1 and COX-2 isoforms. NSAIDs that are selective towards COX-2, such as meloxicam, may have an improved side-effect profile over current NSAIDs. In addition to their use as antiinflammatory agents in the treatment of rheumatoid arthritis and osteoarthritis, selective COX-2 inhibitors may also be beneficial in inhibiting colorectal tumor cell growth and in delaying premature labor.

Publication types

  • Review

MeSH terms

  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / pharmacology*
  • Arthritis, Rheumatoid / drug therapy
  • Arthritis, Rheumatoid / metabolism
  • Aspirin / analogs & derivatives
  • Aspirin / pharmacology*
  • Cyclooxygenase 1
  • Cyclooxygenase 2
  • Cyclooxygenase 2 Inhibitors
  • Cyclooxygenase Inhibitors / pharmacology*
  • Humans
  • Isoenzymes / drug effects
  • Meloxicam
  • Membrane Proteins
  • Osteoarthritis / drug therapy
  • Osteoarthritis / metabolism
  • Prostaglandin-Endoperoxide Synthases / drug effects
  • Prostaglandins / metabolism
  • Thiazines / therapeutic use
  • Thiazoles / therapeutic use


  • Anti-Inflammatory Agents, Non-Steroidal
  • Cyclooxygenase 2 Inhibitors
  • Cyclooxygenase Inhibitors
  • Isoenzymes
  • Membrane Proteins
  • Prostaglandins
  • Thiazines
  • Thiazoles
  • Cyclooxygenase 1
  • Cyclooxygenase 2
  • PTGS1 protein, human
  • PTGS2 protein, human
  • Prostaglandin-Endoperoxide Synthases
  • Aspirin
  • Meloxicam