TABLE 4

Ritonavir pharmacokinetics in plasma and in liver tissue samples from rats receiving 20-mg/kg dosesa

Ritonavir pharmacokinetic parameterValue
PlasmabTissue samplesc
Surgical resectionCNBFNA5FNA3FNA1
Tmax (h)3.03.03.03.03.03.0
Cmax (ng/ml)1,84220,37014,70010,31714,0789,587
AUC0–24 (ng · h/ml)6,91374,68667,48349,16650,53935,461
t1/2 (h)7.012.94.93.65.44.2
  • a One rat (corresponding to the 4-h time point) was excluded from these analyses because ritonavir was not at steady state. Abbreviations: CNB, core needle biopsy; FNA1, fine-needle aspiration with 1 pass; FNA3, fine-needle aspiration with 3 passes; FNA5, fine-needle aspiration with 5 passes; AUC, area under the concentration-time curve; Cmax, maximum observed concentration; t1/2, half-life; Tmax, time of maximum observed concentration.

  • b The plasma concentrations corresponding to 24 and 25 h postdose were below the assay's lower limit of quantitation, and their values were thus set at 0.625 ng/ml.

  • c Concentrations measured in tissue samples were converted from nanograms per gram to nanograms per milliliter by using a liver tissue density value for rats of 1.05 g/ml (32).