Drug Interaction Report

GENERALLY AVOID: Coadministration with tafenoquine may increase the plasma concentrations of drugs that are substrates of organic cation transporter-2 (OCT2) or multidrug and toxin extrusion (MATE) transporters. Clinical drug interaction studies with tafenoquine and OCT2 and MATE substrates have not been conducted in humans. However, in vitro observations suggest the potential for increased concentrations of these substrates, which may result in increased toxicities. Specifically, tafenoquine inhibited metformin transport via human OCT2, MATE-1, and MATE2-K transporters in vitro.

MANAGEMENT: Concomitant use of tafenoquine with OCT2 and MATE substrates should generally be avoided. If coadministration is required, patients should be monitored for drug-related toxicities and dosage reductions considered as needed in accordance with the product labeling of the coadministered drugs.

ADJUST DOSING INTERVAL: Food enhances the oral bioavailability of tafenoquine. According to the manufacturer, tafenoquine peak plasma concentration (Cmax) and systemic exposure (AUC) increased by 31% and 41%, respectively, when administered as an investigational capsule formulation with a high-calorie, high-fat meal (approximately 1000 calories; 15% protein, 25% carbohydrate, 60% fat) relative to the fasted state.

MANAGEMENT: Tafenoquine should be administered with food.