Regorafenib/Strong CYP3A4 Inducers
How the interaction occurs:
Carbamazepine, phenytoin, phenobarbital, rifampin, and St John's Wort may change the way your liver processes regorafenib.
What might happen:
The amount of regorafenib in your blood may increase. You could notice an increase in side effects such as high blood pressure, diarrhea, hand-foot skin reaction, or bleeding.
What you should do about this interaction:
Let your healthcare professionals (e.g. doctor or pharmacist) know that you are taking these medicines together. Your doctor may want you to stop taking St. John's Wort or may monitor you more closely while you are taking carbamazepine, phenytoin, rifampin, phenobarbital or St. John's Wort with regorafenib.If you notice an increase in side effects from your regorafenib, contact your healthcare professional. Your doctor may want to decrease the dose or stop your regorafenib for some time.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.
1.FDA. Drug Approval Package: Stivarga (regorafenib) Tablets, Application:203085, Clinical Pharmacology Review. accessed at: http://www.accessdata.fda.gov/drugsatfda_docs/nda/2012/203085Orig1s000Clin PharmR.pdf approval 09/27/2012.
2.Stivarga (regorafenib) US prescribing information. Bayer HealthCare Pharmaceuticals, Inc. May, 2013.
3.US Food and Drug Administration (FDA). Drug Development and Drug Interactions: Table of Substrates, Inhibitors and Inducers. Available at: http://www.fda.gov/Drugs/DevelopmentApprovalProcess/DevelopmentResources/D rugInteractionsLabeling/ucm093664.htm. Updated 08/05/2011.