Table 1

IC50 values for the effect of various inhibitors on the BL to AP transport of digoxin across Caco-2 and LLC-MDR1 cell monolayers and for midazolam hydroxylation activity in CYP3A4-expression system1-a

InhibitorCaco-2LLC-MDR1CYP3A4-Expression System
Ketoconazole1.501-b 0.0340
L754.394>31-c >31-d 0.0182
  • 1-a  Data represent IC50 values defined as the concentration of inhibitors (μM) necessary to induce a 50% inhibition of digoxin transport (Fig.3) and midazolam hydroxylation activity (Fig. 1).

  • 1-b  No inhibitory effect was observed up to 3 μM ketoconazole.

  • 1-c  89.2 ± 7.7% of control at 3 μM L754.394.

  • 1-d  72.0 ± 9.5% of control at 3 μM L754.394.