As with other HIV integrase inhibitors, bictegravir may be subject to chelation by high concentrations of divalent cations which may result in reduced bictegravir concentrations. Bictegravir and calcium supplements can be coadministered simultaneously. The European product label for Biktarvy recommends they can be taken together without regard to food, but the US product label recommends to administer simultaneously with food. (The decision to administer with or without food should be decided on a case-by-case basis.) The simultaneous administration of calcium carbonate (1200 mg) and bictegravir with food did not significantly modify bictegravir exposure whereas exposure was decreased by 33% when coadministered in fasted conditions. No interaction is expected with emtricitabine and tenofovir alafenamide.