How the interaction occurs:
Some medicines may decrease how much afatinib is absorbed into your blood.
What might happen:
Your afatinib may not work as well.
What you should do about this interaction:
Let your healthcare professionals (e.g. doctor or pharmacist) know that you are taking these medicines together. Make sure they know if you are taking, or have stopped taking carbamazepine, efavirenz, phenytoin, rifampin or St. John's wort. Your doctor may want to adjust the afatinib dose.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.Reference:1.Gilotrif (afatinib) prescribing information. Boehringer Ingelheim Pharmaceuticals, Inc. March, 2016.