Samtidig administration af Tracleer 125 mg 2 gange daglig i 7 dage og rifampicin, en potent inducer af CYP2C9 og CYP3A4, til 9 raske forsøgspersoner reducerede plasmakoncentrationen af bosentan med 58% og denne reduktion kunne være op til næsten 90% i et enkelt tilfælde.
Rifampicin: co-administration in 9 healthy subjects of Tracleer 125 mg twice daily for 7 days and rifampicin, a potent inducer of CYP2C9 and CYP3A4, decreased the plasma concentrations of bosentan by 58%, and this decrease could achieve almost 90% in an individual case.