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A Gauvin

Publications and source records attributed to A Gauvin.

4 recordsLinked to original sources
PubMed2000

High-performance liquid chromatographic determination of vinorelbine in human plasma and blood: application to a pharmacokinetic study.

A sensitive and specific high-performance liquid chromatographic method with fluorescence detection (excitation wavelength: 280 nm; emission wavelength: 360 nm) was developed and validated for the determination of vinorelbine in plasma and blood samples. The sample pretreatment procedure involved two liquid-liquid extraction steps. Vinblastine served as the internal standard. The system uses a Spherisorb cyano analytical column (250x4.6 mm I.D.) packed with 5 microm diameter particles as the stationary phase and a mobile phase of acetonitrile-80 mM ammonium acetate (50:50, v/v) adjusted to pH 2.5 with hydrochloric acid. The assay showed linearity from 1 to 100 ng/ml in plasma and from 2.5 to 100 ng/ml in blood. The limits of quantitation were 1 ng/ml and 2.5 ng/ml, respectively. Precision expressed as RSD was in the range 3.9 to 20% (limit of quantitation). Accuracy ranged from 92 to 120%. Extraction recoveries from plasma and blood averaged 101 and 75%, respectively. This method was used to follow the time course of the concentration of vinorelbine in human plasma and blood samples after a 10-min infusion period of 20 mg/m2 of this drug in patients with metastatic cancer.

Aged↗
PubMed2000

Bayesian estimate of vinorelbine pharmacokinetic parameters in elderly patients with advanced metastatic cancer.

The objective of the present study was to determine the pharmacokinetic profile of vinorelbine in patients 65 years or older with metastatic cancer in progression. Twelve patients were enrolled in this study. Vinorelbine was administered by a 10-min continuous infusion at a dose of 20-30 mg/m2 through a central venous catheter. Chemotherapy was repeated weekly. A total of 46 courses of vinorelbine was studied. Each patient underwent pharmacokinetic evaluation during the first cycle of treatment. Toxicity evaluation was carried out before each course of chemotherapy. Plasma vinorelbine determinations were performed by high-performance liquid chromatography with spectrofluorometric detection. A Bayesian estimation of individual pharmacokinetic parameters was carried out using the nonlinear mixed-effect modeling approach as implemented in the NONMEM computer program. An open three-compartment pharmacokinetic model with a zero order input rate was used to describe the kinetics of vinorelbine. Area under the plasma-concentration time curve (AUC) normalized to a 30 mg/m2 administered dose averaged 0.89 mg/liter x h (coefficient of variation = 23.7%). The total plasma clearance averaged 0.93 liter/h/kg (0.61-1.83 liter/h/kg; coefficient of variation = 38.6%). The elimination half-life was 38.1 +/- 5.8 h. A high correlation was found between patient age and total clearance (r = -0.8; P < 0.001). The main hematological toxicity observed was anemia in 11 patients. Neutropenia occurred in 50% of patients. Significant correlations were found between AUC and the decrease in the hemoglobin level (r = 0.60) and between AUC and the decrease in the neutrophil count (r = 0.66). Thrombocytopenia was observed in only one patient. In conclusion, the age-related decrease in clearance found in this study supports the design of a Phase I study of vinorelbine in patients older than 65 years or perhaps 70 years.

Age Factors↗
PubMed1998

Lower extremity: nonstepping digital angiography with photostimulable imaging plates versus conventional angiography.

PURPOSE: To compare nonstepping digital subtraction angiography (DSA) (ie, storage phosphor radiography adapted to a stationary imaging plate changer) with conventional screen-film angiography in the evaluation of the lower extremities. MATERIALS AND METHODS: Fifty-one patients with peripheral vascular disease underwent both nonstepping DSA and screen-film angiography. The angiographic and radiologic techniques of both systems were kept identical for each patient. Three radiologists independently rated the overall quality of each angiogram. In their evaluations for each of 12 arterial segments on all 102 angiograms, they also rated the degree of opacification, the diameter reduction of the most severe stenosis, and their level of confidence. RESULTS: Mean overall quality scores and levels of confidence were better for nonstepping DSA than for screen-film angiography (P < .001). Full opacification was reported in 95.6% and 89.2% of all 1,836 segments with nonstepping DSA and screen-film angiography, respectively (P < .0001). The difference between the mean stenosis grades obtained with screen-film angiography and nonstepping DSA was not statistically significant. Intertechnique agreements were good (kappa = 0.77, 0.81, and 0.81), whereas interobserver agreements were influenced by the observer's experience with the imaging techniques. CONCLUSION: Nonstepping DSA images of the lower extremity were of better diagnostic quality than were screen-film angiograms. The development of dedicated nonstepping DSA equipment is warranted.

Adult↗