How does ibuprofen affect prostaglandins?
Ibuprofen, like other NSAIDs works by inhibiting the synthesis of prostaglandins, which are fat-like molecules involved in inflammation (swelling), pain and fever.
It achieves this effect on prostaglandin synthesis by blocking cyclooxygenase (COX), an enzyme that is present in various tissues of the body.
Ibuprofen is a nonselective COX inhibitor, in that it inhibits at least two isoforms of cyclooxygenase, COX-1 and COX-2.
Cyclooxygenase (COX) is an enzyme that is responsible for the formation of prostanoids (precursors of prostaglandins).
COX-1 maintains the normal lining of the stomach and is involved in homeostatic balances. This one reason that NSAIDs have problems that can produce ulcers of the stomach.
Cyclooxygenase-2 (COX-2) is primarily present at sites of inflammation.
While both COX-1 and COX-2 convert arachidonic acid to prostaglandin, resulting in pain and inflammation, their other functions make inhibition of COX-1 undesirable while inhibition of COX-2 is considered desirable.
It also seems that both COX-1 and COX-2 have other functions beside those listed above and long term use has produced unwanted side effects.