Determined in vitro inhibitory kinetic parameters of telithromycin vs. OATP1B1 and CYP3A4

TypeDetermined Inhibitory Kinetic Parameter Values
Expt 1Expt 2Expt 3MeanS.D.CV (%)95% CIa
OATP1B1 Ki (IC50) (μM)13.711.311.112.01.4512.18.40–15.6
CYP3A4 Ki (μM)3.684.292.993.650.53114.52.33–4.97
CYP3A4 KI (μM)1.150.7861.201.050.22621.50.489–1.61
CYP3A4 kinact (min−1 )0.024920.030360.027900.027720.002729.80.02096–0.03448
  • Ki vs. the enzyme or transporter (for OATP1B1; assuming competitive inhibition, this equates to the IC50 value in the assay as the probe substrate concentration used is much lower than the Km value). CI, confidence interval; Expt, experiment.

  • a 95% CI was calculated by adding or subtracting the product of the t distribution value (4.303) and the value of the S.D. divided by the square root of the sample size from the determined mean value.