1. Cyclo-oxygenase inhibitors (COX inhibitors)
the drugs have the following effects:
Anti inflammatory action: they provide symptomatic relief from pain and swelling in chronic joint disease i.e. in osteo-arthritis and rheumatoid arthritis. They decrease prostaglandin E2 and prostacyclin reduces vasodilation and, indirectly, oedema. However, the inflammatory cells are not directly reduced.
Analgesic action: it reduces headaches by decreasing prostaglandin mediated vasodilation. This is through the reduction of prostaglandin generation making the nociceptive nerve endings less sensitive to inflammatory mediators like bradykinins and 5-hydroxytryptamine.
Antipyretic action: NSAIDs prevent the release of prostaglandins from interleukin-1 in the central nervous system. This reduces the hypothalamic set point for temperature control, thereby reducing fever.
Examples of NSAIDs are:- aspirin, ibuprofen, naproxen, indomethacin, piroxicam.
Many NSAID’s have different functions and composition but they primarily target fatty acid COX enzymes and thereby inhibiting the production of prostaglandins and thromboxanes. Other functions of NSAID’s in inflammatory effects are:
• Inhibition of vasodilation and oedema to reduce peripheral COX-2-generated prostaglandin synthesis
• Reduce harmful superoxide free radical generation by neutrophils and macrophages
• Uncouple G-protein regulated processes in the cell membrane of inflammatory cells. This reduces their responsiveness to some agonists released by damaged tissue