TABLE 4

IC50 values for inhibition of human liver microsomal codeine glucuronidation determined in the absence and presence of 2% (w/v) bovine serum albumin

Data are given as IC50 ± S.E. of parameter fit. Concentration range of each inhibitor shown in parentheses.

InhibitorIC50
Without BSAWith 2%BSA
μM
Dextropropoxyphene24.6 ± 0.4a2.9 ± 0.2a
(0.69–690 μM)a(0.29–500 μM)a
Fluconazole2970 ± 16371 ± 0.6a
(50–2500 μM)(46–2300 μM)a
Ibuprofen2250 ± 23N.D.b
(1–5 mM)
Ketoconazole17.2 ± 0.11a2.0 ± 0.03a
(4.5–270 μM)a(1.5–90 μM)a
Methadone3.9 ± 0.08a0.7 ± 0.01a
(0.72–360 μM)a(0.28–56 μM)a
Acetaminophen> 30 mM8772 ± 22
(2–30 mM)(2–30 mM)
Salicylic acid> 20 mMN.D.b
(2–20 mM)
Valproic acid4604 ± 509580 ± 1.78a
(1–20 mM)(0.15–8.6 mM)a
  • a IC50 value is the unbound concentration in the incubation medium (i.e. corrected for binding to HLM and BSA).

  • b Not determined because of extensive binding to BSA.