title: A limited sampling model for the pharmacokinetics of etoposide given orally.
abstract: A limited sampling model of etoposide after oral administration to estimate the area under the plasma concentration-time curve from 0 to 24 h (AUC) by determination of the drug plasma levels at only two time points was developed by a multiple regression analysis on a training data set of 15 patients receiving oral doses ranging from 54 to 90 mg/m2. The equation describing the model is AUC (micrograms ml-1 h) = 5.183 (micrograms ml-1 h) + 1.193 (h) x C1h (micrograms/ml) + 8.439 (h) x C4h (micrograms/ml) (R2 = 0.93, P = 0.0001), where C1h and C4h represent the plasma etoposide concentrations at 1 and 4 h, respectively. The model was validated prospectively on a test data set of 13 patients receiving oral doses ranging from 52 to 87 mg/m2 and, additionally, on a data set of 7 patients receiving oral doses ranging between 176 and 200 mg/m2, investigated in a previous study. Validation on both test data sets gave a relative mean predictive error of 0.1% and a relative root mean square error of 15.8% and 16.7%, respectively. The present study shows that it is possible to obtain a good estimate of the plasma AUC after oral administration of etoposide using a two-time-point sampling model. The model can be used to monitor the etoposide AUC in patients receiving chronic oral treatment.
authors.affiliation: Mario Negri Institute for Pharmacological Research, Milan, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Gentili
authors.forename: M
authors.initials: M
authors.lastname: Zucchetti
authors.forename: V
authors.initials: V
authors.lastname: Torri
authors.forename: C
authors.initials: C
authors.lastname: Sessa
authors.forename: J
authors.initials: J
authors.lastname: de Jong
authors.forename: F
authors.initials: F
authors.lastname: Cavalli
authors.forename: M
authors.initials: M
authors.lastname: D'Incalci
mesh_terms: D000284:Administration, Oral; D000368:Aged; D005047:Etoposide / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006801:Humans; D008875:Middle Aged; D008954:Models, Biological; D012044:Regression Analysis; D013048:Specimen Handling
chemical_list: D005047:Etoposide