[Trends in nonsteroidal anti-inflammatory drug development and application]

Since the synthesis of salicylic acid, research into the synthesis of new nonsteroidal anti-inflammatory drugs (NSAIDs) has continued in two directions: drugs with higher anti-inflammatory activity and those causing less adverse side-effects. Several very potent classic, non-selective NSAIDs were already available in the 1970's, but problems with their toxicity, especially gastro- and nephrotoxicity, have remained unsolved. The discovery of two cyclooxygenase (COX) isoforms, COX-1 and COX-2, was a breakthrough that led to obtaining the so-called coxibs, which selectively inhibit COX-2. This property makes this kind of NSAID less gastrotoxic than classic, non-selective NSAIDs. Other strategies to reduce the toxic effects of NSAIDs were their applications as prodrugs or purified enantiomers. The latest are the synthesis of classic NSAIDs combined with a chemical group that serves as a nitric oxide donor or the synthesis of double cyclooxygenase/5-lipoxygenase inhibitors. Simple inhibition of prostaglandin (PG) synthesis cannot completely stop the inflammatory process. Therefore new agents are tested for their influence on many other elements of the mechanism of inflammation, e.g. the formation of inflammatory cytokines, free radicals and biogenic amines by the stimulated inflammatory cells. Such pleiotropic activity of an NSAID might increase its anti-inflammatory action.NSAIDs are widely used not only for their anti-inflammatory, but also analgesic, antipyretic, and (as in case of aspirin) anti-coagulating activity. Results of the latest studies suggest that NSAIDs prevent colorectal cancer and may protect against the development of Alzheimer's disease as well. Precise studies of NSAIDs' mechanism of action (e.g. research on the genetic conditions of NSAID metabolism, the discovery of COX-3, studies on microsomal PGE synthase or PG receptors) will probably enable the synthesis of other more selectively acting compounds.