- Capecitabine - warfarin (Coumadin), cimetidine (Tagamet), allopurinol (Lopurin), sorivudine (Usevir) or brivudine (Brivex), ketoconazole (Nizoral), itraconazole (Sporanox), ritonavir (Norvir), amprenavir (Agenerase) or indinavir (Crixivan)