Etoposide [4'-demethylepipodophyllotoxin-9-(4,6-O-ethylidene)-beta-D-glucopyranoside] is a substrate for P-glycoprotein (P-gp) and cytochrome P450 (CYP) 3A. This study was designed to investigate the effects of quercetin (3,5,7,3',4'-pentahydroxyflavanone), a P-gp and CYP3A inhibitor, on the pharmacokinetics of etoposide in rats. Etoposide was administered to rats orally (9 mg/kg) or i.v. (3 mg...

No standard chemotherapy has been defined for metastatic breast cancer (MBC) patients pretreated with anthracyclines and taxanes. A multicenter phase 2 study was conducted to evaluate the safety and efficacy of oral etoposide in patients with MBC. Eligible patients were treated with repeated cycles of oral etoposide (60 mg/m/d on days 1–10, followed by 11 days of rest). The primary endpoint was...

The breast cancer resistance protein [BCRP (BCRP/ABCG2)] has not previously been directly identified as a source of resistance to epipodophyllotoxins.However, when P-glycoprotein (P-gp)- and Mrp1-deficient mouse fibroblast and kidney cell lines were selected for resistance to etoposide, amplification and overexpression of Bcrp1 emerged as the dominant resistance mechanism in five of five cases....

Etoposide is a drug whose antineoplastic activity is dependent on the schedule of drug administration. This article reviews the rationale for a prolonged schedule of etoposide administration and the therapeutic results of use of such a schedule in the treatment of cancer. The pharmacology of etoposide is also reviewed, with particular attention paid to the pharmacokinetics of oral etoposide and...

Etoposide and morphine are well known P-glycoprotein (P-gp) substrates. The pharmacokinetic effect of morphine on plasma etoposide concentration after the oral concomitant use of etoposide and morphine in rats was assessed using a population analysis approach. A P-gp substrate quinidine and the anticholinergic drug propantheline were also administered with etoposide to compare with the effects ...

BACKGROUND We performed this phase III study to determine whether the addition of 3 months of oral etoposide in non-progressing patients with extensive small-cell lung cancer (SCLC) treated with four cycles of etoposide plus ifosfamide plus cisplatin (VIP) improves progression-free survival (PFS) or overall survival. PATIENTS AND METHODS Patients with extensive SCLC with a Karnofsky performan...

INTRODUCTION The concept of maintenance therapy is one of the highly relevant approaches in the management of advanced ovarian cancer. The fundamental goal of maintenance therapy is to improve survival outcomes. We attempted to reinforce maintenance chemotherapy by adding oral etoposide following taxane administration. CASES We retrospectively evaluated 14 patients with advanced ovarian cance...

There is a continuing need to identify new agents that are active in ovarian cancer. Etoposide is a derivative of the plant alkaloid epipodophyllotoxin. The availability of etoposide in oral preparation allows prolonged administration by the oral route. In this study, activity and toxicity of etoposide in women with recurrent ovarian cancer are described from a case series of women with recurre...

Etoposide, a widely used anticancer drug, exhibits low and variable oral bioavailability mainly because of being substrate for the efflux transporter, P-glycoprotein (P-gp). Therefore, the present study was aimed to investigate the effect of D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) and PEG 400 as P-gp inhibitors on the intestinal absorption of etoposide. Everted sacs of rat smal...

PURPOSE Despite the extensive use of etoposide for the treatment of different malignant neoplasms, its main pharmacokinetic determinants are not completely defined. We aimed to study the impact of P-glycoprotein (P-gp/ABCB1) and the multidrug resistance proteins ABCC2 (MRP2) and ABCC3 (MRP3) on the pharmacokinetics of etoposide. EXPERIMENTAL DESIGN Abcb1a/1b(-/-), Abcc2(-/-), Abcc3(-/-), Abcb...