Relative absorption of the two enantiomers of terbutaline after duodenal administration.

The absorption of the two enantiomers of terbutaline, (+)-terbutaline and (-)-terbutaline, and of the racemate, (+/-)-terbutaline, has been studied in six healthy volunteers using a newly developed intestinal perfusion technique. The area under the plasma concentration curve for the (-)-enantiomer was more than twice that for the (+)-enantiomer. The data demonstrate a clear difference in absorption efficiency between (-)- and (+)-terbutaline, but further studies are required to establish whether (-)-terbutaline influences the absorption of (+)-terbutaline.