Samtidig administration af Tracleer 62, 5 mg to gange dagligt i 6 dage og ketoconazol, der er en stærk CYP3A4- inhibitor, medførte en stigning i plasmakoncentrationen af bosentan til ca. det dobbelte.
Ketoconazole: co-administration of Tracleer 62.5 mg twice daily for 6 days and ketoconazole, a potent CYP3A4 inhibitor, increased the plasma concentrations of bosentan approximately 2-fold.