The significance of differences in the potency of enantiomers of anti-acetylcholine drugs

Abstract

Abstract The anti-acetylcholine potencies of the dimethylaminoethyl and N/-methyl piperidin-4-yl esters of R and S 2-cyclohexyl-2-hydroxy-2-phenylacetic acid and their quaternary derivatives have been measured by in vitro and in vivo procedures. The R-enantiomer of dimethylaminoethyl-2-cyclohexyl-2-hydroxy-2-phenylacetate was approximately 100 times more active than the corresponding S-enantiomer both in vivo and in vitro. In contrast, the differences in potencies of the enantiomers of the other compounds were smaller in vivo than in vitro and moreover, the in vivo differences in potency decreased as the potency of the racemates increased. The relevance of these results to general studies of enantiomeric differences is discussed.