Search results for "Quinolone"
showing 10 items of 108 documents
Mathematical modelling of in situ and in vitro efflux of ciprofloxacin and grepafloxacin
2005
Abstract The efflux process due to p-glycoprotein-like mechanisms of ciprofloxacin (CIP) and grepafloxacin (GRX) has been studied “in situ” in rats and “in vitro” in Caco-2 cells. The results were modelled by a curve fitting procedure which allowed the characterization of the passive (Pd) and carrier mediated parameters (Vm and Km) from the raw data without initial velocities estimation. CIP absorption in rat was characterized as a passive diffusion at the assayed concentrations. Although the involvement of an efflux transporter cannot be ruled out, its relevance in the transport of the fluoroquinolone is negligible. In GRX absorption, an efflux process is implicated and it is detected in b…
Intrinsic Absolute Bioavailability Prediction in Rats Based on In Situ Absorption Rate Constants and/or In Vitro Partition Coefficients: 6‐Fluoroquin…
2000
A preliminary study attempting to predict the intrinsic absolute bioavailability of a group of antibacterial 6-fluoroquinolones-including true and imperfect homologues as well as heterologues-was carried out. The intrinsic absolute bioavailability of the test compounds, F, was assessed on permanently cannulated conscious rats by comparing the trapezoidal normalized areas under the plasma concentration-time curves obtained by intravenous and oral routes (n = 8-12). The high-performance liquid chromatography analytical methods used for plasma samples are described. Prediction of the absolute bioavailability of the compounds was based on their intrinsic rat gut in situ absorption rate constant…
Odorant metabolism catalyzed by olfactory mucosal enzymes influences peripheral olfactory responses in rats.
2013
International audience; A large set of xenobiotic-metabolizing enzymes (XMEs), such as the cytochrome P450 monooxygenases (CYPs), esterases and transferases, are highly expressed in mammalian olfactory mucosa (OM). These enzymes are known to catalyze the biotransformation of exogenous compounds to facilitate elimination. However, the functions of these enzymes in the olfactory epithelium are not clearly understood. In addition to protecting against inhaled toxic compounds, these enzymes could also metabolize odorant molecules, and thus modify their stimulating properties or inactivate them. In the present study, we investigated the in vitro biotransformation of odorant molecules in the rat …
Antibiotic prophylaxis in patients who had undergone to prostate biopsy in between the EMA warning era: effects of fluoroquinolones in diabetic and n…
2022
Abstract Purpose To investigate the effects of different antibiotic prophylaxis regimens in patients with diabetes mellitus (DM) candidates to trans-rectal ultrasound-guided prostate biopsy (TRUSPB). Methods 143 outpatients with DM who underwent TRUSPB during the period 2018–2020 were selected from a cohort of 1150 patients in 3 different institutions. Exclusion criteria were allergies, concomitant anti-platelet therapies and uncontrolled DM. Different antibiotic prophylaxis regimens were adopted. Bacterial resistance levels to fluoroquinolones into the different communities were also collected. Univariable and multivariable binomial logistic regression analyses were used to assess the odds…
Erratum to: Cetuximab-induced skin exanthema: prophylactic and reactive skin therapy are equally effective
2013
Purpose Treatment with cetuximab is accompanied by the development of an acneiform follicular skin exanthema in more than 80 % of patients. Severe exanthema (grade III/IV) develops in about 9–19 % of patients with the necessity of cetuximab dose reduction or cessation. Methods The study presented was a retrospective analysis of 50 gastrointestinal cancer patients treated with cetuximab in combination with either FOLFIRI or FOLFOX. One cohort of 15 patients received an in-house reactive skin protocol upon development of an exanthema. A second cohort of 15 patients received a skin prophylaxis starting with the first dose of cetuximab before clinical signs of toxicity. A third historic group o…
Effects of long-acting bronchodilators in COPD patients according to COPD severity and ICS use
2013
SummaryBackgroundIndacaterol is a once-daily, long-acting β2-agonist bronchodilator that improves dyspnoea and health status in patients with moderate-to-severe COPD. While its bronchodilator effects have been shown to be maintained in different patient subgroups, effects on clinical outcomes in certain subgroups are not yet defined.MethodsPost-hoc analysis of pooled clinical study data to investigate efficacy and safety of indacaterol compared with placebo and other long-acting bronchodilators (formoterol, salmeterol, open-label tiotropium) in patient subgroups defined by COPD severity (GOLD stage II or III; n = 4082) and ICS use at baseline (no/yes; n = 4088). Efficacy outcomes were troug…
Pharmacokinetics, bioavailability and absorption of flumequine in the rat.
1999
Abstract The study demonstrates that the oral extent of bioavailability of flumequine in the rat, relative to the intravenous injection, is complete (0.94±0.04) and not significantly different from that found by the intraduodenal route (0.95±0.04). The rate of oral bioavailability, however, is slow ( k a =1.20±0.07 h −1 ; T max =2.0 h), but enough to maintain plasma levels above the minimal inhibitory concentration of the most common pathogens for an extended period of time (about 10 h). The reason for the oral absorption slowness could be a slow gastric emptying, an adsorption to the gastric mucosae, a precipitation in the gastric medium or any other feature concerning the stomach as the i…
Emergence of tularemia in France: paradigm of the Burgundy region
2011
International audience; We report three consecutive cases of tularemia occurring in Burgundy, France, a region previously considered not endemic for tularemia. The patients presented with varied and unspecific clinical manifestations. The epidemiological circumstances, especially the mode of contamination, were not particularly suggestive of tularemia. Serological diagnosis was delayed in two cases because of the lack of significant antibody titers at the time of admission. In contrast, a diagnosis could readily be obtained in all three cases by detection of Francisella tularensis DNA from clinical samples using PCR-based methods. These cases highlight the increased incidence and geographic…
Biophysical Models as an Approach To Study Passive Absorption in Drug Development: 6-Fluoroquinolones
1995
A preliminary study attempting to assess and explain the intestinal absorption of a series of antibacterial 7-piperazinyl-6-fluoroquinolones is presented. The synthesis, n-octanol partition coefficients, intrinsic rat gut in situ absorption rate constants, and in vitro antibacterial activity data found for these homologous compounds are described. A fluorimetric, reverse-phase HPLC method was performed for the quantification of the quinolones in absorption and partition samples. Equations based on two classic biophysical absorption models are given for predicting the intrinsic absorption features of the series according to the partition data or merely single structural parameters. In situ a…
Synthesis, configuration, and calcium modulatory properties of enantiomerically pure 5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylates.
1992
Enantiomerically pure hexahydroquinolinones of the structural type 9 were prepared by a variation of the Hantzsch synthesis in which an optically active acetoacetate served as a chiral auxiliary reagent. Determinations of the de and ee values are described. The absolute configurations of the optically pure products were characterized by single-crystal X-ray analysis. The antipodes 9a and 9b exhibited calcium antagonistic activities on smooth musculature; the (S)-(-)-enantiomer 9b was the more potent compound with regard to the EC50 values which differed by a factor of 100; the intrinsic activity of 9b was 1.2, compared with a value of 0.54 for 9a. On the other hand, R-(+)-9a exerted positiv…