Table 6

Influence of R-warfarin on quinidine metabolism in human liver microsomes6-a

WarfarinFormation of 3-Hydroxyquinidine
Km 6-b Vmax 6-b
μM μM pmol/min/mg
023.7  ± 3.1150  ± 5
2524.2  ± 2.5155  ± 4
10026.4  ± 3.0166  ± 5
20022.9  ± 5.0151  ± 9
30017.6  ± 3.2137  ± 6
35018.8  ± 4.5139  ± 8
40015.6  ± 0.9128  ± 2
45015.7  ± 0.8126  ± 2
50016.4  ± 2.0141  ± 4
55017.3  ± 4.5141  ± 9
60014.1  ± 1.3130  ± 3
70017.0  ± 3.5134  ± 7

  • ↵6-a  R-Warfarin in methanol and quinidine in distilled water were added to human liver microsomes suspended in phosphate buffer (0.1 M, pH 7.4) containing EDTA.

  • ↵6-b  The kinetic parameters were determined based on the Michaelis-Menten equation. Data are presented as mean ± S.E.