Chiral non-steroidal anti-inflammatory drugs--a review.

A chiral centre is noted in majority of the NSAIDs. For NSAIDs the enantiomer with S configuration almost exclusively possesses the ability to inhibit prostaglandin activity. R-enantiomers of NSAIDs have poor COX inhibitory activity. Some R-enantiomers are not inert, and many have different actions. The R- to S- chiral inversion varies with biological factors and property of NSAID. The S- to R- chiral inversion is rare for all the NSAIDs. Various preclinical and clinical studies have demonstrated that chirally pure NSAIDs like dexketoprofen, dexibuprofen and S-etodolac are more potent than their respective R enantiomers. Favourable pharmacokinetic and pharmacodynamic profile of dexketoprofen, dexibuprofen and S-etodolac make them effective and well tolerated drug for the treatment of painful inflammatory conditions at half doses of recemate. Thus chiral switch of NSAIDs is a rational approach for the treatment of painful inflammatory conditions.