THE CLINICAL-SIGNIFICANCE OF S-(-KETAMI NE())

Among anaesthetic drugs, ketamine occupies a special position. Biochem ically, ketamine is a racemate consisting of equal shares of two optic al enantiomers. Pharmacological investigations show differences betwee n those enantiomers in both qualitative and quantitative properties. F urthermore, clinical superiority of S-(+)-ketamine has been described in different therapeutic studies with regard to anaesthetic potency, t he extent of analgesia, effects and side effects during and after the operation,and undiserable psychological dysfunction. On a neuropharmac ological basis, the clinical superiority of S-(+)-ketamine is due to i ts effect on NMDA receptors in central nervous tissue, opioid receptor s on both central and peripheral levels, and noradrenergic, dopaminerg ic,and serotoninergic mechanisms. The main problems associated with th e ketamine racemate in clinical use are desirable psychological dysfun ction and a prolonged period of arousal. There are grounds for the ass umption that the use of S-(+)-ketamine will minimise those problems wi thout reducing anaesthetic potency or restricting the advantages of ke tamine anaesthesia.