Table 2

Kinetic parameters for ritonavir metabolism by individual liver (LMS) and enterocyte (EMS) microsomes and expressed CYP enzymes

MicrosomesKMVmax
μM pmol/min/mg
LMS 40.992-a 20.32-a
LMS 90.852-a 22.12-a
LMS 100.912-a 17.82-a
Mean ± SD0.92 ± 0.0720.1 ± 2.2
EMS 120.012 64.1
EMS 130.099157.1
EMS 150.077 46.8
Mean ± SD0.063 ± 0.04589.4 ± 59.3
CYP2D61.02-a 0.93a,b
CYP3A40.0681.372-b
CYP3A50.0471.002-b
  • 2-a Calculated for the formation of R3.

  • 2-b Vmax, nmol product/min/nmol CYP.