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Antibiotic Agents (antibiotic + agent)
Selected AbstractsInhibitory effect of erythromycin on potassium currents in rat ventricular myocytes in comparison with disopyramideJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 7 2003Erika Hanada ABSTRACT Disopyramide, a class la antiarrhythmic agent, has been reported to induce torsades de pointes (TdP) associated with excessive QT prolongation in electrocardiogram (ECG), especially when concomitantly administered with erythromycin, a macrolide antibiotic agent. In this study, we have evaluated the effects of erythromycin on action potential duration (APD) and potassium currents in rat ventricular myocytes in comparison with disopyramide. We have evaluated the relationship between in-vitro potassium current inhibition and in-vivo QT prolongation observed in a previous study. Action potentials and membrane potassium currents, including delayed rectifier current (IK) and transient outward current (Ito), were recorded using a whole-cell patch clamp method in enzymatically-dissociated ventricular cells. Erythromycin and disopyramide prolonged APD in a concentration-dependent manner. Disopyramide (10,100 ,m) and erythromycin (100 ,m) led to increases in the APD at 90% repolarization level. Disopyramide reduced IK (IC50 = 37.2 + 0.17 ,m) and Ito (IC50 = 20.9 + 0.13 ,m) while erythromycin reduced IK (IC50 = 60.1 + 0.29 ,m) but not Ito. The observed prolongation of APD might be ascribed to the inhibition of potassium currents. Erythromycin produced the prolongation of APD and the inhibition of potassium currents with a lag time after addition of the drugs, which suggested that erythromycin might not reach potassium channels from outside the ventricular cells. The potency of disopyramide was almost equivalent under in-vitro and in-vivo conditions. However, potency of erythromycin in-vitro was far weaker than that in-vivo reported in a previous study, presumably due to a difference in the uptake of erythromycin into ventricular myocytes between in-vivo and in-vitro conditions. Therefore, when drug-induced risks of QT prolongation are to be evaluated, the difference of potencies between in-vitro and in-vivo should be taken into consideration. [source] Topical Antibacterial Agents for Wound Care: A PrimerDERMATOLOGIC SURGERY, Issue 6 2003Candace Thornton Spann MD Although often overlooked, topical antibiotic agents play an important role in dermatology. Their many uses include prophylaxis against cutaneous infections, treatment of minor wounds and infections, and elimination of nasal carriage of Stapylococcus aureus. For these indications, they are advantageous over their systemic counterparts because they deliver a higher concentration of medication directly to the desired area and are less frequently implicated in causing bacterial resistance. The ideal topical antibiotic has a broad spectrum of activity, has persistent antibacterial effects, and has minimal toxicity or incidence of allergy. [source] Effect of rapid influenza testing on the clinical management of paediatric influenzaINFLUENZA AND OTHER RESPIRATORY VIRUSES, Issue 3 2009Lance C. Jennings Background, Rapid tests are now widely available to assist the diagnosis of influenza; implementation may optimise the use of antiviral and antibiotic agents in the clinical management of influenza. Objective, To explore the clinical management of children with influenza-like illness (ILI) when rapid influenza tests were and were not performed. Methods, Between 15 January 2007 and 30 April 2007, a standardised questionnaire was used to record the clinical features of children aged 1,12 years who presented to office-based paediatricians in Germany with febrile ILI during periods of local influenza activity. For each paediatric contact, a clinical diagnosis of either ,influenza positive', ,influenza negative' or ,suspected ILI' was made. Where performed, the outcome of a Clearview Exact Influenza A + B rapid test was recorded. Prescriptions for antiviral agents and antibiotic medications were also recorded. Results, A total of 16 907 questionnaires were evaluated. After fever (an entry criteria for all children), cough (84·6%), fatigue/decreased activity (83·0%), rhinorrhoea (73·7%) and headache (67·1%) were the most common symptoms. Influenza was clinically diagnosed in 56·8% (9596/16 907) of cases. The antiviral oseltamivir was prescribed for 24·6% (178/725) of children who were influenza positive by symptom assessment alone and 60·1% (4618/7685) of children who were influenza positive by rapid test. Antibiotics were less commonly prescribed for children who were influenza positive by rapid test [3·5% (271/7685) versus 17·2% (125/725) for symptom assessment alone]. Conclusions, In children with ILI, a positive rapid test result for influenza promotes the rational use of antiviral agents and reduces the inappropriate use of antibiotic medications. [source] A general method for the fluorine-18 labelling of fluoroquinolone antibioticsJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 8 2003Oliver Langer Abstract Fluoroquinolones are an important class of antibiotic agents with a broad spectrum of antibacterial activity. Labelling of fluoroquinolones with fluorine-18 is of interest for the performance of pharmacokinetic measurements and the visualization of bacterial infections in humans with positron emission tomography. A two-step radiosynthetic pathway to prepare fluorine-18-labelled ciprofloxacin (1-cyclopropyl-6-[18F]fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-quinoline-3-carboxylic acid) has previously been developed. In the present work this approach was applied to the preparation of the structurally related compounds [18F]norfloxacin (1-ethyl-6-[18F]fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-quinoline-3-carboxylic acid) and [18F]pefloxacin (1-ethyl-6-[18F]fluoro-1,4-dihydro-7-(4-methyl-1-piperazinyl)-4-oxo-quinoline-3-carboxylic acid). The first step of the radiosynthesis consisted of a 18F for 19F exchange reaction on a 7-chloro-substituted precursor molecule, followed by coupling reactions with the amines piperazine or 1-methylpiperazine. Starting from 51,58 GBq of [18F]fluoride 1.9,2.0 GBq of [18F]norfloxacin or [18F]pefloxacin, ready for intravenous injection, could be obtained in a synthesis time of 130 min (3.5,3.8% overall radiochemical yield). Moreover, the preparation of [18F]levofloxacin ((-)-(S)-9-[18F]fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylicacid) was attempted but failed to afford the desired product in practical amounts. Copyright © 2003 John Wiley & Sons, Ltd. [source] Salmonella enterica serotype Virchow: epidemiology, resistance patterns and molecular characterisation of an invasive Salmonella serotype in IsraelCLINICAL MICROBIOLOGY AND INFECTION, Issue 10 2006M. Weinberger Abstract This study outlines the unique epidemiology of Salmonella enterica serotype Virchow in Israel. Between 1997 and 2002, the overall incidence of non-typhoid Salmonella enterica (NTS) decreased from 69.3 to 53.3 infections/100 000 population, but the incidence of S. Virchow increased (from 7.2 to 9.1 infections/100 000). Since 2000, S. Virchow has become the second-ranking NTS isolate, accounting for 17% and 27% of all stool and blood NTS isolates, respectively. Infants aged <,1 year had the highest incidence of isolation from stools (92.8/100 000). The incidence of isolation from blood was highest for infants aged <1 year (4.4/100 000). Only 6% of isolates were susceptible to all ten antibiotic agents tested; 34% were resistant to one agent, 54% to one to three agents, and 40% to four to six agents. A high proportion of the tested isolates were resistant to nalidixic acid (89%), streptomycin (56%), tetracycline (43%), trimethoprim,sulphamethoxazole (38%) and chloramphenicol (28%), but none to ciprofloxacin or ceftriaxone. Pulsed-field gel electrophoresis revealed two closely related clusters, each containing a predominant pulsotype. Coupled with its invasive propensity, the increasing incidence of highly resistant S. Virchow in Israel is of real concern. Future research should focus on the sources of S. Virchow in the food chain in order to institute effective control measures. [source] | ||||||||||