The therapy's safety is the most important aim of modern medicine today. Introducing new medicine is connected with increasing therapy's effectiveness and its safety as well as with optimizing production's the costs. There is one question which need to be asked, if new medicine's advantages could outnumber potential risk of increasing the production's costs.

What can be noticed nowadays is the strong tendency of introducing new medicines in form of pure isomers (enantiomers). Enantiomers possess an asymmetric carbon atom that's why can be include to chiral drugs. Development of asymmetrical analysis allowed the division of racemic solution and introducing preparations in form of pure enanciomers with better properties into pharmaceutical market.

The aim of this study, based on available references, is to compare characteristics of racemic drug - bupivacaine with drugs containing pure enanciomers - levobupivacaine and ropivacaine. Based on available research findings activities of both medicines were confronted. In addition undesirable effects of bupivacaine, levobupivacaine and ropivacaine on nervous and cardiovascular systems were compared. This study includes as well effectiveness and safety of mentioned drugs taking into consideration the type of clinic application. Keywords: stereochemistry, anesthetics locale,bupivacaine, levobupivacaine, ropivacaine.