[Pharmacokinetic implications associated to the use of drugs as racemates or pure enantiomers].

This article critically reviews the recent specialized literature concerning the influence of the stereochemical nature of quiral drugs on the pharmacokinetic processes and its pharmacological implications. Evidence is presented indicating that as a function of the type of enantiomer administered, profound differences in the pharmacokinetic profiles, e.g. absorption, distribution, biotransformation and elimination can occur. As a consequence of the enantioselective nature of the drug-organism interaction, major differences in the therapeutic responses can be envisaged depending on whether the drug is administered as a pure enantiomer or as a racemic mixture.