Macitentan Interactions

• Moderate dual CYP3A4 and CYP2C9 inhibitors (fluconazole, amiodarone) or use of combined CYP3A4 and CYP2C9 inhibitors may increase exposure to macitentan: avoid co-administration with macitentan ( 7.3, 12.3 ). 7.3 Moderate Dual or Combined CYP3A4 and CYP2C9 Inhibitors Concomitant use of moderate dual inhibitors of CYP3A4 and CYP2C9 such as fluconazole is predicted to increase macitentan exposure approximately 4-fold based on physiologically based pharmacokinetic (PBPK) modeling. Avoid concomitant use of macitentan with moderate dual inhibitors of CYP3A4 and CYP2C9 (such as fluconazole and amiodarone) [ see Clinical Pharmacology (12.3) ] .

Source: FDA drug label - macitentan

• Strong CYP3A4 inhibitors (ketoconazole, ritonavir) increase exposure to macitentan: avoid co-administration with macitentan ( 7.2 , 12.3 ). 7.2 Strong CYP3A4 Inhibitors Concomitant use of strong CYP3A4 inhibitors like ketoconazole approximately double macitentan exposure.

Source: FDA drug label - macitentan

• Strong CYP3A4 inhibitors (ketoconazole, ritonavir) increase exposure to macitentan: avoid co-administration with macitentan ( 7.2 , 12.3 ). Many HIV drugs like ritonavir are strong inhibitors of CYP3A4.

Source: FDA drug label - macitentan