Population pharmacokinetics and pharmacodynamics of oral etoposide.

Aims: To study the population pharmacokinetics and pharmacodynamics of oral etoposide in patients with solid tumours.

Methods: A prospective, open label, cross-over, bioavailability study was performed in 50 adult patients with miscellaneous, advanced stage solid tumours, who were receiving oral (100 mg capsules) etoposide for 14 days and i.v.

Effect of cyclosporin A on protein binding of teniposide in cancer patients.

We investigated the effect of cyclosporin A (CSA) on protein binding of teniposide (VM26) in 16 patients with metastatic renal cell carcinoma receiving i.v. VM26 alone over 24 h (total dose, 200 mg/m2) and in association with CSA (5 mg/kg/2 h followed by 30 mg/kg/48 h i.

Dose-finding and pharmacologic study of chronic oral idarubicin therapy in metastatic breast cancer patients.

Oral idarubicin (IDA) is an active drug in metastatic breast cancer, but its role in the management of this tumor is yet not established completely. To investigate a new modality of IDA administration, a dose-finding study was designed with hyperfractionated doses. The purpose was to determine the maximum tolerated dose (MTD), the dose-limiting toxicity (DLT), and the pharmacokinetics of this schedule.

Interactions of antineoplastic chemotherapy with zidovudine pharmacokinetics in patients with HIV-related neoplasms.

To evaluate the perturbations in zidovudine (ZDV) pharmacokinetics as a consequence of antineoplastic chemotherapeutic treatments, we performed a prospective crossover study in 13 HIV-infected patients with cancer. The subjects received 2-day regimens of ZDV (250 mg x 2/day). On the first day ZDV was administered alone, whereas on the second day it was combined with antitumor chemotherapies specific for the histological type (ZDV + chemotherapy).

Pharmacokinetic and pharmacodynamic effects of high-dose continuous intravenous verapamil infusion: clinical experience in the intensive care unit.

Objective: Our study aimed at evaluating the pharmacokinetic, cardiovascular, and metabolic effects of high-dose verapamil continuous intravenous infusion in cancer patients.

Design: Prospective clinical and pharmacokinetic study.

Setting: Intensive care unit of a Cancer Research Institute.

Pharmacokinetics of oral etoposide in patients with hepatocellular carcinoma.

Etoposide dosage in patients with liver dysfunction remains controversial. Since etoposide has a hepatic component to its clearance (CL) and shows a high degree of protein binding, hepatic impairment could affect etoposide disposition. However, the empiric recommendation that the dose of etoposide be decreased in such patients may reduce systemic exposure and be detrimental to its antitumor activity.

Pharmacology of chronic oral daily administration of idarubicin.

Idarubicin (4-demethoxydaunorubicin) (IDA) is a daunorubicin analogue with substantial activity in hematologic malignancies and solid tumors. Among several reasons, IDA is of interest because of its main metabolite derivative, the C-13 alcohol analogue, idarubicinol (IDOL). Previous studies have suggested that IDOL, unlike other anthracycline metabolic derivatives, possesses a striking growth-inhibitory activity in tumor cell lines.

Non-linear pharmacokinetics of high-dose intravenous verapamil.

Aims: In an attempt to reverse multidrug resistance, in a recent trial of verapamil in association with doxorubicin, we used escalating doses of continuous intravenous (i.v.) verapamil under close haemodynamic monitoring.

Paclitaxel as a radiosensitiser: a proposed schedule of administration based on in vitro data and pharmacokinetic calculations.

Paclitaxel is efficacious against many human cancers. Because it blocks cells at the radiosensitive G2-M interface, paclitaxel has been investigated as a radiosensitiser. The results have been equivocal and somewhat contradictory.

Pharmacokinetics and tolerance of vinorelbine in elderly patients with metastatic breast cancer.

25 patients older than 65 years with metastatic breast cancer were treated with vinorelbine 30 mg/m2 i.v. days 1 and 8 every 3 weeks; the pharmacokinetics were studied in 10 of them.

Determination of unbound etoposide concentration in ultrafiltered plasma by high-performance liquid chromatography with fluorimetric detection.

Etoposide is a highly protein bound drug, and monitoring the concentration of free drug could help individualize dosage in oncological patients. The cost and difficulty of the standard techniques (equilibration dialysis) has hampered the monitoring of free drugs. We describe a simple HPLC method for the measurement of free etoposide concentration in plasma.

Sensitive high-performance liquid chromatographic method with fluorescence detection for measurement of vinorelbine plasma concentrations.

A high-performance liquid chromatographic (HPLC) method with fluorescence detection for the determination of vinorelbine in plasma is described. The technique was derived from that published by Debal for an assay of vinorelbine in cell culture medium. The modifications concern the preparation procedure for plasma samples (a two-step liquid-liquid extraction from plasma is described), optimization of the mobile phase composition, and use of a single C18 column.

Pharmacokinetics of vinorelbine in patients with liver metastases.

Background: The main elimination pathway of vinorelbine is hepatic metabolism, and the clearance of vinorelbine could be reduced in patients with liver metastases.

Objectives: To study the pharmacokinetics of vinorelbine in patients who have advanced breast cancer with or without liver metastases and to study the relationship between hepatic function and vinorelbine clearance.

Patients And Methods: We studied 29 patients with advanced breast cancer: 19 with liver metastases and 10 control patients with extrahepatic metastases (mean age, 61 years; age range, 38 to 81 years).

Are current pediatric dose recommendations for intravenous theophylline appropriate?

Theophylline, a first-line antiasthma drug, is often associated with severe toxicity even when taken in the recommended schedule. Theophylline toxicity has been associated with upper respiratory tract infections (URTI) due to reduced total-body clearance of theophylline. Some researchers believe this inhibition stems from a direct effect of viruses, but others postulate it is a result of the fever.

Chronopharmacology of methotrexate pharmacokinetics in childhood leukemia.

Survival has been shown to improve when maintenance therapy for acute lymphocytic leukemia in children is given at night rather during the day. We examined the possibility that diurnal variation in methotrexate pharmacokinetics may contribute to this improvement. In a crossover study, we determined the pharmacokinetics of intravenous methotrexate at 10:00 and 21:00 h in six children with standard or high-risk leukemia.

The perception of teratogenic risk of cocaine.

While there has been a substantial increase in recreational use of cocaine by young adults, conclusive evidence for cocaine teratogenicity in humans is lacking, and even those believing the drug is teratogenic agree that the rates are quite small. While counseling pregnant women on their teratogenic risk, it was our impression that there is an unrealistically high perception of reproductive risk of cocaine. We wished to quantify the perception of teratogenic risk of cocaine by the public, physicians, and by pregnant women who were counseled following gestational exposure to the drug.

Pain perception and effectiveness of the eutectic mixture of local anesthetics in children undergoing venipuncture.

The emulsion of lidocaine and prilocaine (EMLA) is effective in preventing the pain of venipuncture in children. It is therefore important to identify children who could benefit the most from EMLA. We studied the safety and feasibility of two methods of application of EMLA (patch and cream) in a randomized, open-label trial of EMLA patch versus EMLA cream in 160 children with chronic diseases undergoing venipuncture.

Analgesia in children with sickle cell crisis: comparison of intermittent opioids vs. continuous intravenous infusion of morphine and placebo-controlled study of oxygen inhalation.

The objectives of the study were to compare the efficacy and safety of a continuous infusion (CIV) of morphine and intermittent parenteral opioids (IPO) in children with sickle cell vaso-occlusive crises (VOCs); to determine whether 50% oxygen administration through a face mask can reduce the duration of severe pain in patients receiving CIV morphine; and to measure morphine concentration at steady state for pharmacokinetic and pharmacodynamic analysis in patients receiving CIV morphine. The study was designed as a prospective, controlled, "before-and-after" evaluation of two different analgesic regimens. For patients receiving CIV morphine, there was a randomized, double-blind, placebo-controlled study of O2 vs.

Oxygen therapy in sickle cell disease.

The effect of oxygen therapy on the number of irreversibly (ISC) and reversibly (RSC) sickled cells was studied in patients with sickle cell anemia. Inhalation of 50% oxygen in patients who were not in crisis produced a significant fall in RSCs and a lesser fall in ISCs. Twenty-five subjects in sickle cell crisis were chosen at random to receive either oxygen (15 patients) or air (10 patients).

The effects of cardiac transplantation and cyclosporine therapy on digoxin pharmacokinetics.

Most patients needing cardiac transplantation are treated with digoxin for heart failure. Because of its narrow therapeutic range, even recommended doses of digoxin may cause severe toxicity. Several drugs, including quinidine, amiodarone, verapamil, and propafenone can interact with digoxin, leading to toxic accumulation of the glycoside.

Cytochrome P450IID subfamily in non-human primates. Catalytical and immunological characterization.

Interindividual variations of debrisoquine metabolism was recently identified in non-human primates tested in vivo. The catalytical and immunological characterization of cytochrome P450IID subfamily was undertaken in hepatic microsomes from extensive metabolizer primates. The NADPH/O2 mediated metabolism of debrisoquine, dextromethorphan and bufuralol was similar to the kinetics reported in humans.