Drug Interaction Report

MONITOR: Coadministration with inhibitors of P-glycoprotein (P-gp) may increase the plasma concentrations of monomethyl auristatin E (MMAE), the microtubule-disrupting component of brentuximab vedotin. In vitro, MMAE was found to be a substrate of the P-gp efflux transporter.

MANAGEMENT: Caution is advised when brentuximab is used with P-gp inhibitors. Close monitoring for adverse effects including neutropenia, infection, peripheral neuropathy, and hepatotoxicity is recommended.

ADJUST DOSE: Smoking tobacco may decrease the steady-state systemic exposure of istradefylline by 38% to 54%.

MANAGEMENT: The possibility of reduced therapeutic effects of istradefylline should be considered in smokers. The manufacturer recommends an istradefylline dosage of 40 mg once daily in patients who smoke 20 or more cigarettes (or the equivalent amount of another tobacco product) per day.