Udhayvir Grewal: Three important drug-drug interactions to watch out for with capecitabine

Udhayvir Grewal, Resident Physician at Ochsner LSU Health Shreveport Academic Medical Centre, recently shared a post on X:

“Three important drug-drug interactions to watch out for with capecitabine (list not comprehensive, there could certainly be many others):

• Warfarin: exaggerated anticoagulant activity. Closely monitor INR, adjust warfarin doses accordingly. Switch to DOAC if no clear indication?
• Allopurinol: The conversion of capecitabine to 5-FU and then to FdUMP and FUTP may be reduced via inhibition of phosphorylation by Capecitabine. Consider other urate lowering drugs such as febuxostat or probenecid if possible.
• Proton pump inhibitors: Reduced dissolution of the capecitabine tablet due to increased gastric pH, leading to decreased capecitabine absorption. Consider alternative agents like H2RAs, etc if possible (this may not be feasible in all cases).”

Source: Udhayvir Grewal/X