CF- DDIs Flashcards
Ivacaftor is a substrate of what CYP enzyme?
CYP3A
Tezacaftor and elexacaftor are substrates of what CYP enzyme?
CYP3A
Tezacaftor and elexacaftor are mild inducers of what CYP enzyme?
CYP3A
Lumacaftor is a strong inducer of what CYP enzyme?
CYP3A
What happens if lumacaftor/ivacaftor (Orkambi) is added to a regimen that includes a strong CYP3A inhibitor?
Decrease the Orkambi does to 1 tablet PO QD during first week of treatment
What happens if a strong CYP3A inhibitor is added to a regimen that already contains Orkambi?
No dose adjustment needed
Moderate CYP3A inhibition drugs
Erythromycin, fluconazole
What happens to ivacaftor’s AUC and Cmax in a DDI with erythromycin or fluconazole?
The AUC and Cmax increase
How to dose adjust Ivacaftor in a DDI with erythromycin or fluconazole
QD dosing
What happens to tezacaftor and elexacaftor’s AUCs and Cmaxes in a DDI with erythromycin or fluconazole?
The AUC and Cmax increase for both of them
How to dose adjust tezacfator and elexacaftor in a DDI with erythromycin or fluconazole
QOD dosing, alternating between Symdeko (tezacaftor/ivacaftor) or Trikafta and ivacaftor
Strong CYP3A inhibition drugs
Clarithromycin, itraconazole
What happens to ivacaftor’s AUC and Cmax in a DDI with clarithromycin or itraconazole?
The AUC and Cmax increase A LOT
How to dose adjust ivacaftor in a DDI with clarithromycin or itraconazole
BIW dosing of ivacaftor
What happens to tezacaftor and elexacaftor’s AUCs and Cmaxes in a DDI with clarithromycin or itraconazole?
The AUC and Cmax for both increase (not as much as ivacaftor though)
