The drug-drug interactions in various treatments are often a focus point, especially in relation to the oral tyrosine kinase inhibitors (TKIs); however, what is the significance of food-drug interactions especially with oral agents such as nilotinib (Tasigna), sunitinib (Sutent), sorafenib (Nexavar), and erlotinib (Tarceva), to name a few?

Clinical trials have determined that fat absorption is increased with some of the oral TKIs, especially nilotinib, when taken with meals. Spacing medications from meals decreases the possibility of interactions between the medications and fats in foods. On the other hand, taking agents such as capecitabine (Xeloda) with food can reduce the rate and extent of drug absorption by as much as 65% and 35%, respectively, thus impacting drug efficacy. CYP3A4 pathways are common pathways of drug metabolism for many of these agents, and grapefruit, for example, is a common CYP3A4 inhibitor. Thus, consumption of the citrus fruit increases the plasma concentration of many drugs, which in turn increases the probability of drug toxicities. — Jiajoyce R. Conway, DNP, FNP-BC, AOCNP®, NP-C ONA