Cancer chemotherapy and pharmacology
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Cancer Chemother. Pharmacol. · Sep 2002
Population pharmacokinetic and limited sampling models for carboplatin administered in high-dose combination regimens with peripheral blood stem cell support.
By means of a nonlinear mixed effect modeling technique, a population pharmacokinetic (PK) model was developed to evaluate the effects of a variety of covariates on clearance and other pharmacokinetic parameters of ultrafilterable carboplatin administered in high-dose combination regimens with peripheral blood stem cell support. In addition, single-sample and two-sample limited sampling models (LSMs) were derived to estimate carboplatin's AUC that could be used in the design of drug dosing regimens. ⋯ Both a population PK model and a LSM for high-dose carboplatin were developed following its administration in combination chemotherapeutic regimens with peripheral blood stem cell support. In both cases, the models performed well when analyzed in the context of the retrospective and bootstrap analyses. Prospective studies in ovarian cancer patients should be conducted to further tailor the current models.
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Cancer Chemother. Pharmacol. · Sep 2002
Case ReportsExtremely high exposures in an obese patient receiving high-dose cyclophosphamide, thiotepa and carboplatin.
An obese 53-year-old woman (height 167 cm, weight 130 kg) with metastatic breast cancer received high-dose chemotherapy comprising cyclophosphamide, thiotepa and carboplatin (CTC). The cyclophosphamide (1 g/m(2) per day) and thiotepa (80 mg/m(2) per day) doses were based on body surface area (BSA) calculated using total body weight (TBW). The daily carboplatin dose was calculated based on the Calvert formula, using a target area under the plasma concentration-time curve (AUC) value of 3.25 mg.min/ml and applying the Cockcroft-Gault equation to estimate the glomerular filtration rate. ⋯ It is concluded that cyclophosphamide and thiotepa in obese patients should not be dosed on the basis of BSA incorporating TBW since the patient will be overexposed. Moreover, applying the Cockcroft-Gault equation to obese patients leads to an overprediction of creatinine clearance and, when used in the Calvert equation, consequently to a carboplatin dose that is too high. Obese patients represent a unique group of patients in which TDM is extremely valuable in optimizing dosing, particularly in high-dose chemotherapy.