Drug Interactions between bortezomib and nilotinib

GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of nilotinib. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. Because nilotinib is associated with concentration-dependent prolongation of the QT interval, increased levels may potentiate the risk of ventricular arrhythmias such as torsade de pointes and sudden death.

ADJUST DOSING INTERVAL: Food increases the oral bioavailability of nilotinib. The mechanism of interaction is unknown. Compared to the fast state, nilotinib systemic exposure (AUC) increased by 82% when the dose was given 30 minutes after a high-fat meal. Because nilotinib is associated with concentration-dependent prolongation of the QT interval, increased levels may potentiate the risk of ventricular arrhythmias such as torsade de pointes and sudden death.

MANAGEMENT: Patients treated with nilotinib should avoid consumption of grapefruit, grapefruit juice, and any supplement containing grapefruit extract. In addition, no food should be consumed for at least 2 hours before and 1 hour after a nilotinib dose.

GENERALLY AVOID: Data from in vitro and animal (mice) studies suggest that green tea may antagonize the cytotoxic effects of bortezomib. Polyphenols in green tea such as (-)-epigallocatechin gallate (EGCG) have been shown to block the proteasome inhibitory action of bortezomib in multiple myeloma and glioblastoma cancer cell lines. The mechanism appears to involve a direct chemical reaction between the boronic acid moiety of bortezomib and the 1,2-benzenediol groups present in certain polyphenols leading to inactivation of bortezomib. However, one group of investigators reported that no antagonism of bortezomib was observed in preclinical in vivo experiments where EGCG plasma concentrations are commensurate with dietary or supplemental intake.

MANAGEMENT: Until more data are available, it may be advisable to avoid or limit consumption of green tea and green tea products during treatment with bortezomib. The interaction has not been demonstrated for other, non-boronic acid proteasome inhibitors.