Table 3.

Predicting potential of OATP1B1-based drug-drug interaction.

Drug	Half Maximum Inhibition Concentration (IC50, μM)	Dose (mg/mmol)	Molecular Weight (g/mol)	Peak Plasma Concentration (Cmax, μM)	Maximal Hepatic Inlet Concentration ([I]inlet,max, μM)	Predicted R Value
Simvastatin Acid	4.3	80/0.183	436.6	0.058 (40)	12.274	3.85
Omeprazole	84.3	80/0.232	345.42	4.146 (42)	19.586	1.23
Alprazolam	99.5	3/0.01	308.76	0.333 (43)	0.981	1.01
Desloratadine	140.5	5/0.16	310.8	0.015 (44)	1.088	1.01

Dose is the highest proposed clinical dose; C_max is the peak plasma concentration at the highest proposed clinical dose; [I]_inlet,max was estimated as C_max + (k_a x Dose x F_aF_g/Q_h) (13), where Q_h is the hepatic blood flow (1500 mL/min), k_a is the absorption rate constant, and F_aF_g is the fraction of oral dose that reaches the liver. Because the values of k_a and F_aF_g were not available, for conservative predictions, they were assumed equal to the theoretical maxima of 0.1 min⁻¹ and 1 (13), respectively. R values were estimated as 1 + [I]_inlet,max/K_i. Because the concentration of E₂17βDG (1 μM) was well below its K_m (45, 46), the K_is were approximated by the IC₅₀s based on K_i = IC₅₀/(1 + [S]/K_m) (47). For simvastatin acid, the C_max and dose were assumed equal to those of simvastatin. For desloratadine, R values were estimated with the C_max following the highest clinical dose of desloratadine since it is higher than the C_max following that of loratadine (48, 49).