PURPOSE: To investigate the pharmacokinetics and pharmacodynamics of paclitaxel in a randomized comparative study with four different treatment arms in patients with platinum-pretreated ovarian carcinoma. PATIENTS AND METHODS: Eighteen patients were entered onto this study in which paclitaxel was administered at a high dose of 175 mg/m2 versus a low dose of 135 mg/m2 on a 3- or 24-hour infusion schedule. A solid-phase extraction technique for sample pretreatment followed by a reverse-phase high-performance liquid chromatographic (HPLC) assay was used for analysis of plasma. RESULTS:Grade 3 neutropenia occurred in all four treatment arms. However, it was more severe on the 24-hour infusion schedule. Paclitaxel concentrations as low as 0.012 mumol/L were measured with the HPLC assay. With this low quantitation threshold, we found the plasma disappearance of paclitaxel to be triphasic, with half-lives t1/2(alpha), t1/2(beta), and t1/2(gamma) mean values for the different treatment arms of 0.19 hours (range, 0.01 to 0.4), 1.9 hours (range, 0.5 to 2.8), and 20.7 hours (range, 4 to 65), respectively. Eleven possible metabolites were found, of which three were identified as taxanes by on-line HPLC-photodiode array (PDA) detection. Investigation of pharmacodynamics shows no clear relationship between the pharmacokinetic parameters area under the plasma concentration time curve (AUC), area under the plasma concentration moment curve (AUMC), maximal plasma concentration (Cmax), clearance, and toxicity. However, a relationship was found between the duration of plasma concentrations above a threshold of 0.1 mumol/L with absolute neutrophil count (ANC) and white blood cell count (WBC). CONCLUSION:Paclitaxel is metabolized, and putative metabolic products can be found in plasma of patients treated with the drug. Our results indicate that myelosuppression can be predicted by the measurement of the duration of plasma concentrations above the threshold of 0.1 mumol/L.
RCT Entities:
PURPOSE: To investigate the pharmacokinetics and pharmacodynamics of paclitaxel in a randomized comparative study with four different treatment arms in patients with platinum-pretreated ovarian carcinoma. PATIENTS AND METHODS: Eighteen patients were entered onto this study in which paclitaxel was administered at a high dose of 175 mg/m2 versus a low dose of 135 mg/m2 on a 3- or 24-hour infusion schedule. A solid-phase extraction technique for sample pretreatment followed by a reverse-phase high-performance liquid chromatographic (HPLC) assay was used for analysis of plasma. RESULTS: Grade 3 neutropenia occurred in all four treatment arms. However, it was more severe on the 24-hour infusion schedule. Paclitaxel concentrations as low as 0.012 mumol/L were measured with the HPLC assay. With this low quantitation threshold, we found the plasma disappearance of paclitaxel to be triphasic, with half-lives t1/2(alpha), t1/2(beta), and t1/2(gamma) mean values for the different treatment arms of 0.19 hours (range, 0.01 to 0.4), 1.9 hours (range, 0.5 to 2.8), and 20.7 hours (range, 4 to 65), respectively. Eleven possible metabolites were found, of which three were identified as taxanes by on-line HPLC-photodiode array (PDA) detection. Investigation of pharmacodynamics shows no clear relationship between the pharmacokinetic parameters area under the plasma concentration time curve (AUC), area under the plasma concentration moment curve (AUMC), maximal plasma concentration (Cmax), clearance, and toxicity. However, a relationship was found between the duration of plasma concentrations above a threshold of 0.1 mumol/L with absolute neutrophil count (ANC) and white blood cell count (WBC). CONCLUSION:Paclitaxel is metabolized, and putative metabolic products can be found in plasma of patients treated with the drug. Our results indicate that myelosuppression can be predicted by the measurement of the duration of plasma concentrations above the threshold of 0.1 mumol/L.
Authors: Wolfgang Boehmerle; Ute Splittgerber; Michael B Lazarus; Kathleen M McKenzie; David G Johnston; David J Austin; Barbara E Ehrlich Journal: Proc Natl Acad Sci U S A Date: 2006-11-17 Impact factor: 11.205
Authors: Danny Chen; Sae Heum Song; M Guillaume Wientjes; Teng Kuang Yeh; Liang Zhao; Miguel Villalona-Calero; Gregory A Otterson; Rhonda Jensen; Michael Grever; Anthony J Murgo; Jessie L-S Au Journal: Pharm Res Date: 2006-05-25 Impact factor: 4.200
Authors: Milly E de Jonge; Alwin Dr Huitema; Jan Hm Schellens; Sjoerd Rodenhuis; Jos H Beijnen Journal: Br J Clin Pharmacol Date: 2005-03 Impact factor: 4.335
Authors: S J Sollott; L Cheng; R R Pauly; G M Jenkins; R E Monticone; M Kuzuya; J P Froehlich; M T Crow; E G Lakatta; E K Rowinsky Journal: J Clin Invest Date: 1995-04 Impact factor: 14.808
Authors: Sophie Callies; Dinesh P de Alwis; Adrian Harris; Paul Vasey; Jos H Beijnen; Jan H Schellens; Michael Burgess; Leon Aarons Journal: Br J Clin Pharmacol Date: 2003-07 Impact factor: 4.335