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An enzyme immunoassay (EIA) was developed based on a generic and highly sensitive monoclonal antibody (mAb) enabling simultaneous detection of all fluoroquinolone/quinolone antibiotics (FQs) approved for the treatment of food-producing animals. To generate the group-specific antibody, norfloxacin was conjugated to glucose oxidase (GlcOX) by one-step carbodiimide method and used as immunogen. For the establishment and optimization of a direct, competitive EIA, three different FQ-horseradish peroxidase (HRP) conjugates were generated. Best results were obtained by using a hapten-heterologous conjugate (clinafloxacin-HRP) prepared by applying a simple and highly efficient periodate method. Under optimized conditions, the assay showed a very high sensitivity, e.g., the detection limit for norfloxacin was 0.02 ng/mL. Furthermore, due to the high affinity of the employed mAb, all FQs approved within the EU for the treatment of food-producing animals can be detected well below their maximum residue levels (MRLs) with IC50 values ranging from 0.16 ng/mL (marbofloxacin) to 3.82 ng/mL (sarafloxacin). Additionally, the established EIA showed cross-reactivity with 23 other FQs and IC50 values ranged from 0.05 ng/mL (rufloxacin) to 73.2 ng/mL (pradofloxacin). Thus, the established EIA could be potentially applied both for the detection of approved and illegally used quinolones in food. To demonstrate the applicability of the assay, artificially contaminated milk, meat, fish, and shrimp samples were analyzed; mean recovery rates were 88.9%, 76.2%, 74.4%, and 77.9%, respectively. These data demonstrate that the developed EIA is suited for the rapid and sensitive monitoring of FQs residues in animal-derived food.

Coacervation and phase separation were first reported in salt-free catanionic surfactant aqueous systems based on lauric acid (LA) and dodecyltrimethylammonium hydroxide (DTAOH), using hexafluoroisopropanol (HFIP) as a coacervate-inducing agent. The liquid–liquid two-phase separation occurs over a wide of LA/DTAOH molar ratios (78:22–0:100 mol/mol) and total surfactant concentrations (5–200 mmol L−1) upon adding a small amount of HFIP (

In this work we obtained polyclonal antibodies for levofloxacin. We synthesized conjugates of levofloxacin with cationized BSA for immunization and with ovalbumin for development of an ELISA for the detection of levofloxacin. The method is characterized by a range of detectable concentrations of 0.03 ng/mL to 0.41 ng /mL and the limit of detectable concentrations is 0.01 ng/mL. We tested the 28 fluoroquinolones for cross reactivity and only ofloxacin (145%), marbofloxacin (82%), ofloxacin in its dextrorotatory form (68%), rufloxacin (67%), and garenoxacin (24%) had cross reactivity. The optimized ELISA technique allowed the detection of levofloxacin in milk from 0.33 ng/mL to 3.34 ng/mL. The recoveries were in the range of 89.5–102% with a relative standard deviation of 3%. We tested 45 real samples of milk purchased in local stores; for 5 of them the results were positive (near 1 ng/mL).

With the aim of the development of a new radiopharmaceutical for infection imaging, able to differentiate between septic and aseptic inflammations, 99m Tc-rufloxacin was obtained. Its radiochemical yield reaches 93.4 ± 3% under optimum conditions (addition of 99m TcO4 — to a solution containing 50 mg of rufloxacin and 50 μg of SnCl2·2H2O at pH 6). 99m Tc-rufloxacin biodistribution studies in Albino mice bearing septic and aseptic inflammation models showed that 99m Tc-rufloxacin is able to differentiate between septic and aseptic inflammations.

Fluoroquinolones (FQs) are important antimicrobials that exhibit activity against a wide range of bacterial pathogens and excellent tissue permeation. They exist as charged molecules in biological fluids, and thus, their disposition depends heavily on active transport and facilitative diffusion. A recent review of the clinical literature indicated that tubular secretion and reabsorption are major determinants of their half-life in plasma, efficacy, and drug-drug interactions. In particular, reported in vivo interactions between FQs and cationic drugs affecting renal clearance implicated organic cation transporters (OCTs). In this study, 13 FQs, ciprofloxacin, enoxacin, fleroxacin, gatifloxacin, levofloxacin, lomefloxacin, moxifloxacin, norfloxacin, ofloxacin, pefloxacin, prulifloxacin, rufloxacin, and sparfloxacin, were screened for their ability to inhibit transport activity of human OCT1 (hOCT1) (SLC22A1), hOCT2 (SLC22A2), and hOCT3 (SLC22A3). All, with the exception of enoxacin, significantly inhibited hOCT1-mediated uptake under initial test conditions. None of the FQs inhibited hOCT2, and only moxifloxacin inhibited hOCT3 (∼30%), even at a 1,000-fold excess. Gatifloxacin, moxifloxacin, prulifloxacin, and sparfloxacin were determined to be competitive inhibitors of hOCT1. Inhibition constants ( K i ) were estimated to be 250 ± 18 μM, 161 ± 19 μM, 136 ± 33 μM, and 94 ± 8 μM, respectively. Moxifloxacin competitively inhibited hOCT3-mediated uptake, with a K i value of 1,598 ± 146 μM. Despite expression in enterocytes (luminal), hepatocytes (sinusoidal), and proximal tubule cells (basolateral), hOCT3 does not appear to contribute significantly to FQ disposition. However, hOCT1 in the sinusoidal membrane of hepatocytes, and potentially the basolateral membrane of proximal tubule cells, is likely to play a role in the disposition of these antimicrobial agents.

Background: The eradication rates of first-line treatment for Helicobacter pylori infection are not satisfactory. Various regimens including quadruple therapies have been recommended as rescue therapies after the first H. pylori eradication attempt failed. Aims: To compare the efficacy and safety between quadruple therapies with medications containing either rufloxacin or levofloxacin in the Chinese nonulcer dyspepsia patients infected with H. pylori. Methods: One hundred and thirty-eight patients after an unsuccessful 10-day standard triple therapy were enrolled in this study. They were randomized to receive a 14-day quadruple therapy with pantoprazole, bismuth citrate, and furazolidone in combination with either rufloxacin (Group Ruf, n = 70) or levofloxacin (Group Lev, n = 68). The H. pylori eradication was evaluated by 13C-urea breath test 4 and 12 weeks after therapy was completed. Results: One hundred and twenty-seven patients (65 in Group Ruf and 62 in Group Lev) completed the study. The H. pylori eradication rates in Group Ruf were 81.4% for intention-to-treat (ITT) analysis and 87.7% for per-protocol (PP) analysis. The rates were statistically significantly higher than those in Group Lev (66.2% and 72.6%) (p

The photolabile and phototoxic fluoroquinolone (FQ) antibacterial drugs norfloxacin and rufloxacin have been used as capping agents for 25 nm Ag nanoparticles, exploiting the noncovalent interaction between the cationic piperazinyl ring of both FQs and the negatively charged metal surface. The resulting FQ-protected silver nanoclusters (Ag@FQs), ca. 80 nm in diameter, are dispersible in phosphate buffer at physiological pH and their response to light excitation has been studied by steady-state and time-resolved spectroscopic and photochemical techniques. The fluorescence emission of the FQs chromophores is not extensively quenched in the Ag@FQs. In contrast, both Ag@FQs exhibit a photochemical stability more than one order of magnitude larger than that of the free drugs. This is the result of significant and differentiated quenching effects by the Ag surface on the kinetic and population of the excited triplet states of FQs, which are the key intermediate in the drugs photodecomposition. In view of the well-known antimicrobial properties of the Ag nanoparticles, the Ag@FQs could represent intriguing nanohybrids in the perspective multifunctional nanodrugs.

A method to determine five fluoroquinolones (FQs), namely, rufloxacin (RUF), ciprofloxacin (CIP), enrofloxacin (ENO), gatifloxacin (GAT) and moxifloxacin (MOX), in acidic buffer by capillary electrophoresis (CE)-capacitively coupled contactless conductivity detection (C4D) technique is presented. Separation was carried out in a fused-silica capillary (42 cm × 50 μm) using a buffer composed of 10 mM tartaric acid, 14 mM sodium acetate and 15% (v/v) methanol at pH 3.8. The RSDs of the migration times and peak areas were 0.65% and 12.3% (intraday), 1.28% and 8.8% (interday), respectively. CE-C4D in combination with liquid–liquid extraction (LLE) as clean-up and preconcentration procedure, allows detection of the FQs in fortified chicken muscle samples with detection limits of 6.8–11.7 ng/g. This method shows potential in rapid determination of FQs in samples with complex matrix.

A rapid, capillary electrophoresis–potential gradient detection method was developed for determining three fluoroquinolones: rufloxacin, enoxacin, and moxifloxacin. The fluoroquinolones were baseline separated within 3.5 min with background electrolyte composed of 50 mM acetic acid and 6 mM potassium hydroxide at pH 3.7. For the first time, electrokinetic injection was applied in capillary electrophoretic separation of fluoroquinolones, and an average of ca. 10-fold improvement in detection limits was observed. The method was applied to a fortified chicken tissue sample with detection limits (S/N = 3) of 22–24 ng g−1, suggesting the potential of the method for determining fluoroquinolone residues in real samples.

Cimetidine, a substrate for P-glycoprotein (P-gp), is a well known drug interacting with a variety of drugs and results in alteration of pharmacokinetic parameters by concomitant administration. The aim of present study was to investigate whether cimetidine affects the transport of various quinolone antibiotics in human colorectal cancer cell line (Caco-2) system which has been typically used to investigate drug transport via P-gp. The apparent permeability coefficients (P) value of 9 quinolone antibiotics in the co-treatment with cimetidine was examined. Apical to basolateral (AP-to-BL) transport of fleroxacin in the co-treatment with cimetidine was increased to 1.5-fold (p values of gatifloxacin, moxifloxacin, ciprofloxacin and rufloxacin also were changed by cimetidine. These results have a potential that cimetidine influences on the pharmacokinetics of quinolone antibiotics. It suggests that careful drug monitoring and dosage adjustment may be necessary during the co-administration of quinolone antibiotics with cimetidine.

Photodegradation of ofloxacin (OFX) under aerobic conditions gives rise to N-demethylation, mainly involving coupling of radical cation OFX(*)(+ )()with superoxide radical anion. Although H(2)O(2) is produced as a byproduct, oxidative damage to DNA to give 8-OH-dGuo is associated with a type II mechanism. When the photosensitizing potentials of OFX and rufloxacin (RFX) are compared under the same conditions, the latter is shown to produce a much higher degree of DNA oxidation despite the close structural similarity. This is explained by a decrease of the triplet energy when sulfur instead of oxygen is attached to position 8 of the fluoroquinolone ring system. As a consequence, phosphate anions are able to quench OFX triplet but not RFX triplet; this reveals that the reaction medium has a strong influence on the photochemistry of OFX and hence on its photobiological properties.

Objective: To analyse and compare with one another and with other antibacterial drugs the adverse drug reactions (ADRs) of the different fluoroquinolones currently used in Italy, spontaneously reported from doctors in three northern Italian regions. Methods: The data on fluoroquinolones and other antibacterials were obtained from the spontaneous reporting system database of Emilia Romagna, Lombardy and the Veneto, which are the principal contributors to the Italian spontaneous surveillance system. The fluoroquinolone ADRs with a causality assessment of certain, probable or possible (according to WHO criteria), reported between January 1999 and December 2001, were selected and toxicity profiles of individual drugs were described and compared with one another. The reports were also correlated with sex and age of patients and with regional prescription data to estimate individual fluoroquinolone reporting rate of adverse events. Results: During the study period, 10 011 reports were received by the system (a mean annual reporting rate of approximately 185 per million inhabitants): 1920 referred to systemic antimicrobials, of which 432 (22.5%) involved fluoroquinolones. Pefloxacin was associated with the highest reporting rate (982 reports/daily defined dose/1000 inhabitants/day), followed by moxifloxacin (356), rufloxacin (221) and lomefloxacin (196). The most frequently reported reactions to fluoroquinolones involved the skin, but their percentage (25%) was significantly lower (p < 0.01) than those of other systemic antimicrobials (58.5%), whereas the percentages of reactions involving the central nervous (12.2 vs 3.6%), musculoskeletal (14.7 vs 0.3%) and psychiatric systems (9.3 vs 1.8%) were significantly higher (p < 0.01). We found some significant differences in the safety profiles of individual fluoroquinolones: ciprofloxacin was more frequently associated with skin reactions (p < 0.01), levofloxacin and pefloxacin with musculoskeletal (p < 0.01), and rufloxacin with psychiatric disorders (p < 0.05). Levofloxacin was the fluoroquinolone associated with the highest rate of serious tendon disorders; phototoxic reactions were more frequent with lomefloxacin, and toxic epidermal necrolysis and Stevens-Johnson syndrome were seen only with ciprofloxacin. Conclusions: The differences in the safety profiles should be taken into account when prescribing a fluoroquinolone to individual patients.

The role played by type I (radical) and type II (singlet oxygen) mechanisms in the Rufloxacin (RFX)-photoinduced production of 8-hydroxy-2'-deoxyguanosine in DNA has been evaluated. This fluoroquinolone drug has been shown to be able to photoinduce increased levels of some DNA base oxidation products, such as 8-OH-dGuo, that are indicative of mutagenic and carcinogenic events, with probable implications in aging processes. The relative weight of the two photosensitization mechanisms was obtained via determination of two different photoproducts of 2'-deoxyguanosine (dGuo), which are diagnostic of the two different pathways, namely, (4R)- and (4S)-4,8-dihydro-4-hydroxy-8-oxo-2'-deoxyguanosine and 2,2-diamino-4-[(2-deoxy-beta-D-erythro-pentofuranosyl)amino]-2,5-dihydrooxazol-5-one. The observed predominance of type II reaction is in agreement with the fact that the triplet state of RFX is able to transfer with high efficiency its energy to molecular oxygen, giving rise to singlet oxygen. Photophysical measurements suggest that hydrated electrons produced by Rufloxacin photoionization react with dGuo, Thd, and DNA, whereas these biomolecules quench the RFX triplet state with low efficiency. Static quenching of Rufloxacin fluorescence indicates an interaction of this drug both with DNA and with dGuo. On the basis of these experimental data, Rufloxacin photosensitization of DNA is proposed to occur by a type II mechanism.

Our aim was to compare weekly rufloxacin with daily norfloxacin in the secondary prophylaxis of spontaneous bacterial peritonitis and to examine changes in antibiotic susceptibility in fecal Eschericia coli. The method used was an open randomized clinical trial including 79 patients who received either norfloxacin 400 mg/day or rufloxacin 400 mg/week and followed up for one year. E. coli counts, quinolone susceptibility, and drug concentrations in feces were investigated in 12 patients. Cumulative one-year probability of peritonitis recurrence was 26% for patients on norfloxacin and 36% for those on rufloxacin (P = 0.16). Norfloxacin was more effective in the prevention of peritonitis recurrence due to Enterobacteriaceae (0% vs 22%, P = .01). At the end of follow-up, all 12 patients had E. coli resistant to quinolones in their feces. In conclusion, weekly rufloxacin is not an alternative to daily norfloxacin in the prevention of peritonitis recurrence. The development of quinolone-resistant E. coli in feces may be an important problem in patients on long-term quinolone prophylaxis.

Aim of the present work was to investigate the effect of somecyclodextrins (CDs) on the solubility and ocular bioavailability of rufloxacin base (RUF), with theultimate goal of developing an ophthalmic formulation. Phase solubility studies of RUF inpH 7.4 buffer were carried out in the presence of β-cyclodextrin (β-CD),hydroxypropyl-β-cyclodextrin (HP-β-CD) and γ-cyclodextrin(γ-CD). The effect of hydroxypropyl methylcellulose (HPMC) on RUF solubility was evaluated after heating the solutionscontaining HP-β-CD at 120 °C.

A novel chemiluminescence (CL) flow system for rufloxacin (RFX) combined flow-injection analysis is presented in this paper. It is based on the energy transfer from RFX to europium(III), the intense luminescence instead of the weak CL produced by cerium(IV)–sulfurous acid–RFX CL system can be observed when Eu(III) was added to the system. A narrow and highly intense emission band at 617 nm arised from the excited-state Eu(III) was obtained. Under the optimum experimental conditions, the linear range was 2.0 × 10 −8 to 5.0 × 10 −7 M and the detection limit was 5.0 × 10 −9 M. The method has been successfully applied to determination RFX in dosage form, serum samples and urine samples. The recoveries were 95.0–104.9% for serum and urine samples. © 2001 Elsevier Science B.V. All rights reserved.

Quinolones have a selective effect on the normal human intestinal microflora. Published data on 13 different quinolone agents [ciprofloxacin, enoxacin, norfloxacin, ofloxacin, pefloxacin, lomefloxacin, levofloxacin, sparfloxacin, rufloxacin, sitafloxacin (DU-6859a), gatifloxacin, trovafloxacin and moxifloxacin] show that Gram-negative aerobic bacteria, especially Enterobacteriaceae, are strongly suppressed or eliminated during therapy. Gram-positive aerobic cocci are affected strongly by administration of sitafloxacin and moxifloxacin and to minor degrees by the other quinolones. Three new quinolones — gatifloxacin, trovafloxacin and moxifloxacin — are very active against anaerobic bacteria in vitro but have minor effects on the anaerobic intestinal human microflora. Similar findings have been reported for the other 10 quinolones. Thus, the quinolone antibacterials have an ecological impact on the human intestinal microflora, mainly on the enterobacteria, that should be taken into account when these agents are used for prophylaxis or treatment of gastrointestinal bacterial infections.

In order to characterize the protein binding of a drug, it is necessary to have a method which is close to in vivo conditions and fast in the course of measurement. The continuous ultrafiltration fulfils both requirements for substances with a high extent of protein binding. In this study, 18 gyrase inhibitors in clinical practice, characterized by a lower extent of protein binding, were subjected to the titration procedure of the continuous ultrafiltration using bovine and human serum albumin (BSA, HSA), and human plasma. The results of the continuous ultrafiltration were found to be similar to those obtained by means of the 'classical' discontinuous ultrafiltration using plasma (correlation between continuous and discontinuous ultrafiltration r2 = 0.87). In the cases of pipemidic acid, enoxacin and rufloxacin, the continuous method gave approximately 20% lower degrees of protein binding than the discontinuous procedure, which utilizes plasma having the full range of proteins. It is likely that these drugs bind mainly to other proteins in plasma than HSA. This finding proves that this fast method is worthwhile in the whole range of protein binding.

The in vitro inhibitory and bactericidal activities of the investigational fluoroquinolone trovafloxacin were studied and compared with those of five other fluoroquinolones (ciprofloxacin, ofloxacin, pefloxacin, rufloxacin and sparfloxacin) against a wide range of clinical isolates from Italian hospitals. Against gram-positive bacteria, trovafloxacin was overall more active than the other antibiotics tested, including sparfloxacin, another gram-positive-oriented fluoroquinolone, and was active against all ciprofloxacin-resistant streptococci, enterococci, and listeriae, all ciprofloxacin-resistant Staphylococcus aureus isolates and most ciprofloxacin-resistant coagulase-negative staphylococci. Its antistaphylococcal activity was not affected by oxacillin resistance or susceptibility of the isolates, nor was its antipneumococcal activity affected by whether isolates were susceptible or resistant to penicillin. Against gram-negative bacteria, trovafloxacin retained a high potency mostly comparable with that of ciprofloxacin. Rufloxacin and pefloxacin were less active than the other fluoroquinolones against most test strains of both gram-positive and gram-negative organisms. Trovafloxacin minimal bactericidal concentrations usually equalled or exceeded by 2–4 times the minimal inhibitory concentration values, indicating that the compound is overall highly bactericidal.

The activity of eight topoisomerase inhibitors was investigated against five clinical isolates of Pneumocystis carinii. Susceptibility tests were performed by inoculation of the organisms on to a cell monolayer and parasites were counted after 72 h incubation at 37 degrees C. Culture plates were added with Dulbecco's modified Eagle's medium containing serial dilutions of lomefloxacin, norfloxacin, ofloxacin, pefloxacin, rufloxacin, camptothecin, amsacrine and etoposide. Atovaquone, pentamide isethionate and co-trimoxazole were used as control drugs. Etoposide gave inhibition comparable to that observed with atovaquone. Poor activity was demonstrated by pefloxacin, while the other topoisomerase inhibitors had no significant effect.

The objectives of this study were to characterize the pharmacokinetics of 1-5-fluoro-2-pyridyl)-6-fluoro-7-(4-methyl-1- piperazinyl)-1,4-dihydro-4-oxoquinolone-3-carboxylic acid hydrochloride (DW-116), a newly developed quinolone antibiotic, and to compare these kinetics with those of ciprofloxacin and rufloxacin, representative quinolone antibiotics, in rats. Rats were subjected to surgery involving catheterization of the femoral vein and artery. DW-116 (4, 20, or 200 mg/kg), ciprofloxacin (20 mg/kg), or rufloxacin (20 mg/kg) was administered either intravenously (iv) or orally. Blood samples were collected at various times and subjected to an HPLC assay for the quinolones. Temporal profiles of plasma concentration after iv administrations of DW-116 at doses of 4, 20, and 200 mg/kg exhibited an apparent multiexponential decline. In the three doses examined, systemic clearance and steady-state volume of distribution of DW-116, calculated by model-independent methods, were in the range 0.17 approximately 0.23 L/h/kg and 2.90 approximately 4.44 L/kg, respectively. When DW-116 was given orally at doses of 4, 20, or 200 mg/kg, the AUC values were nearly identical to those following iv administration, indicating an almost complete absorption (i.e., the percent bioavailability was 90.0 for 4 mg/kg, 99.0 for 20 mg/kg, and 98.3 for 200 mg/kg) in the dose range examined. The absorption of DW-116 appears to be extremely rapid because the mean residence time calculated from the oral administration data was not significantly different from that for the iv administration. At a dose of 20 mg/kg, the mean residence time for iv administered ciprofloxacin and rufloxacin was smaller than that of DW-116, indicating that DW-116 remains in the body longer than the other quinolones. Absolute percent bioavailabilities of ciprofloxacin (69.9%) and rufloxacin (84.9%) were smaller than that obtained for DW-116 (99.0%). Because it has been reported that the in vivo antibacterial activity of DW-116 is comparable or superior to that of rufloxacin and ciprofloxacin, despite the fact that the in vitro activity is significantly lower, the pharmacokinetics of this antibiotic may be responsible, at least in part, for the enhanced in vivo antibacterial activity of DW-116.

The pharmacokinetics of rufloxacin were evaluated in patients with acute exacerbations of chronic bronchitis. The drug was administered once-a-day for 10 consecutive days following two different dosage schedules. The first group of 56 patients was given a loading dose of 300 mg on day 1 and 150 mg on the subsequent 9 days. A second group of 55 patients received a loading dose of 400 mg followed by 200 mg for the subsequent 9 days. In each patient, three blood samples were collected during and after treatment. Rufloxacin plasma levels were determined by high performance liquid chromatography. A one-compartment model for repeated doses was employed to estimate the pharmacokinetic parameters. The data were analysed by nonlinear mixed effects modelling using the NONMEM program. The apparent clearance and volume of distribution were found to depend on body weight and gender: the elimination half-life in males (mean weight 73.7 kg) being 30 h and in females (mean weight 71.7 kg) 27 h (68% prediction intervals 9.5–93.9 and 8.6–85.4 h, respectively). The calculated peak plasma concentration at steady state for the 200 mg per day regimen was 4.81 mg/l, while the trough concentration was 2.75 mg/l. The pharmacokinetic parameters of rufloxacin were close to those measured in previous formal studies in a small number of patients but with numerous blood samples. The study also showed that a 200 mg daily oral dose of rufloxacin preceded by a loading dose of 400 mg produced steady state plasma concentrations above the minimum inhibitory concentrations for most susceptible pathogens.

The efficacy and safety of rufloxacin (400 mg, single dose) were compared to those of norfloxacin (400 mg twice a day for 3 days) for the treatment of women with uncomplicated cystitis. In addition, urine levels, drug level/MIC ratio, and urine antibacterial activity 72 to 84 h after treatment initiation were determined in a subgroup of patients for pharmacodynamic assessment. A total of 203 women were included and treated in this open, randomized clinical trial; 100 patients received norfloxacin, whereas 103 received rufloxacin. Of these, 156 (74 and 82 patients in the norfloxacin and rufloxacin groups, respectively) were considered bacteriologically evaluable. At the first follow-up visits (3 to 12 days after starting the treatment), bacteriological cure rates were 99 and 94% for norfloxacin and rufloxacin, respectively. Seventy-nine percent (119 of 150) of bacteriologically cured patients attended a long-term follow-up visit (4 to 6 weeks after starting the treatment), where a relapse rate of 4% (2 of 54) and 5% (3 of 64) were found in the norfloxacin and rufloxacin groups, respectively. The pharmacodynamic evaluation performed in 35 patients showed similar median urine levels (approximately equal to 25 micrograms/ml) and urine antibacterial activity for both treatment groups against initial isolates, despite a higher norfloxacin level/MIC ratio due to the lower MIC of norfloxacin. Twenty-one patients (20%) in the rufloxacin group and 12 patients (12%) in the norfloxacin group reported 39 and 16 adverse events, respectively, almost all of them being mild and lasting < 24 h. Overall, gastrointestinal reactions were the most frequent adverse events reported. However, 12 patients treated with rufloxacin reported 15 central nervous system adverse events. This study shows that single doses of rufloxacin are as effective as a norfloxacin 3-day standard treatment in uncomplicated cystitis. The results obtained with rufloxacin are consistent with its pharmacodynamic properties.

The antibacterial activity of rufloxacin was confirmed against a large number of respiratory and urinary tract pathogens collected in five European countries. In terms of both MIC90 values and percentages of susceptible isolates found, this new quinolone showed useful in-vitro activity against Mycoplasma catarrhalis, Haemophilus influenzae and Klebsiella pneumoniae, with a large proportion of Staphylococcus aureus also covered, while, as expected Streptococcus pneumoniae and Streptococcus pyogenes were not included in its antibacterial spectrum. Rufloxacin was comparable with the other antibiotics against these pathogens with the exception of streptococci. Against these microorganisms, beta-lactams were the most active agents. Against the urinary pathogens the in-vitro activity of rufloxacin is similar to that of norfloxacin although this latter drug is more active in terms of MIC90 values and in percentages of strains inhibited. In many cases more isolates were susceptible to the remaining comparator agents than to rufloxacin. However, there were no significant differences between the numbers of microorganisms inhibited by the various drugs and rufloxacin. The findings of this survey do not seem to modify the general picture which emerged in previous studies and further confirms its useful spectrum in different geographic settings.

The in vitro activity of rufloxacin, alone and in combination with its metabolite (MF 922) against common respiratory and urinary tract pathogens and anaerobes was assessed. No synergistic interaction between rufloxacin and MF 922 was observed by the checkerboard technique against aerobic bacteria. When the time-kill system was employed, 24 synergistic interactions were noted out of 30 tests performed (80%), of which 14 (100%) were with Enterobacteriaceae isolates, 2 with Moraxella catarrhalis (50%), 4 with Haemophilus influenzae (100%), 2 with Staphylococcus aureus (50%) and 2 with Streptococcus pneumoniae and Streptococcus pyogenes (50%). Synergism was found with all Bacteroides fragilis irrespectively of the method used. Rufloxacin alone or in combination with MF 922, at concentrations achieved in vivo, induced morphological alterations in all the pathogens analyzed with the exception of M. catarrhalis and H. influenzae. Towards S. pyogenes and S. pneumoniae, the same levels of rufloxacin and MF 922 were capable of inducing only bacteriostatic rather than bactericidal effect, followed by reversible morphological modifications. The presence of 50% human serum in the test media did not affect the results.

Purpose: We compare the bacteriological and clinical efficacy of rufloxacin and ciprofloxacin in patients with acute uncomplicated pyelonephritis.Materials and Methods: A total of 110 outpatients was enrolled in a randomized, double-blind multicenter study and treated for 10 days with 200 mg. rufloxacin daily (after a loading dose of 400 mg. on day 1) or 500 mg. ciprofloxacin twice daily. Bacteriological and clinical efficacy was based on the accumulated outcomes assessed at the end of treatment, and at 2 and 4 to 6 weeks.Results: The bacteriological and clinical success rates of rufloxacin and ciprofloxacin were comparable: 55.6 percent versus 58.8 percent and 74 percent versus 71 percent, respectively (95 percent confidence interval -28 percent to +22 percent and -20 percent to +25 percent, respectively). Both study medications were well tolerated.Conclusions: Rufloxacin once daily is a good alternative in the outpatient treatment of acute uncomplicated pyelonephritis.

In a randomised, multicentre study, 179 hospitalised adults with bacterial exacerbations of chronic bronchitis were given either rufloxacin 200mg once daily (loading dose of 400mg on day 1) [n = 90] or ciprofloxacin 500mg twice daily (n = 89). The duration of treatment was 5 days with rufloxacin and 7 days with ciprofloxacin. In pretreatment sputum samples a pathogen was isolated in 115 patients (64%), the most common isolates being Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis. On day 8, clinical cure or improvement was achieved in 89% of the patients in the rufloxacin group and in 91% of the ciprofloxacin group; bacteriological cure was obtained in 79 and 82% of the 2 groups, respectively. At 2-week follow-up, the clinical success rate was 92% with rufloxacin and 99% with ciprofloxacin; the bacteriological success rate was 86 and 85%, respectively. Most of the failures observed with both quinolones were caused by Pseudomonas aeruginosa. Adverse events, mostly gastrointestinal-related, occurred in 9% of the patients in both treatment groups. This study shows that 5-day treatment with rufloxacin once daily is comparable with a conventional 7-day treatment with ciprofloxacin twice daily in patients with bacterial exacerbations of chronic bronchitis caused by susceptible bacteria.

The suppression of faecal Escherichia coli by quinolones was studied in a randomized cross-over phase I trial with single oral doses of 400 mg rufloxacin or norfloxacin. Both drugs caused > 70% decontamination in a similar number of subjects in the 72 h post-dose period (83% vs 100% respectively), but suppression of E. coli at 168 h was significantly (P < 0.05) higher after rufloxacin (83.3 vs 40%).

In a double-blind, randomized, multicenter study, 463 adult women with symptomatic acute uncomplicated cystitis were treated orally with either a 400-mg single dose of rufloxacin (n = 226) or an 800-mg single dose of pefloxacin (n = 237). Escherichia coli (78%) and Proteus mirabilis (7%) were the most common isolates from 350 patients with significant pretreatment bacteriuria (uropathogens, > or = 10(5) CFU/ml). In the intention-to-treat analysis of patients with significant pretreatment bacteriuria, 343 patients were assessed for bacteriological outcome and 345 were assessed for clinical outcome. The bacteriological cure rate was 88% in the rufloxacin group and 84% in the pefloxacin group (95% confidence interval [CI] for difference in proportions, -4 to 12%), while the clinical resolution rate was 85 and 84%, respectively (95% CI, -8 to 9%). The per-protocol analysis demonstrated that among the 264 assessable patients, the bacteriological cure rate obtained with rufloxacin at 4 weeks of follow-up was comparable to that with pefloxacin (91 versus 85%; 95% CI, -3 to 15%). Among 295 clinically assessable patients, the clinical resolution rate at 4 weeks of follow-up was 89% in the rufloxacin group and 88% in the pefloxacin group (95% CI, -6 to 10%). Potentially drug-related adverse events occurred in 19% of the rufloxacin patients and in 18% of the pefloxacin patients. A single oral dose of 400 mg of rufloxacin is as effective and safe as a single oral dose of 800 mg of pefloxacin for the treatment of acute uncomplicated cystitis in women.

The in vitro activities of rufloxacin and its metabolite, MF 922, were compared with those of ofloxacin, ciprofloxacin, erythromycin, and minocycline against Mycoplasma pneumoniae, Mycoplasma hominis, Mycoplasma fermentans, and Ureaplasma urealyticum. Rufloxacin, MF 922, and ciprofloxacin shared similar activities against all mycoplasmas tested. (MICs for 90% of isolates tested [MIC90s], 0.5 to 4 micrograms/ml. Ofloxacin had the lowest MIC90s for U. urealyticum, M. fermentans, and M. hominis (MIC90s, 0.25 to 1 micrograms/ml) and erythromycin had the lowest MIC90 for M. pneumoniae (MIC90, 0.004 micrograms/ml).

The protective effects of ciprofloxacin and rufloxacin were compared to those of rifampicin againstMycobacterium tuberculosis infections in mice and in guinea pigs. Rifampicin was very protective in both models. In tubercular infections produced in mice, ciprofloxacin (30 mg/kg) showed slight protection but none was observed in guinea pigs. Rufloxacin, was weakly active in guinea pigs but inactive in mice.

1. The behavioural and convulsant effects of imipenem, a carbapenem derivative, were studied after i.p. administration in DBA/2 mice, a strain genetically susceptible to sound-induced seizures and in Swiss mice. 2. It was found that DBA/2 mice were more susceptible to seizures induced by imipenem than Swiss mice. 3. The proconvulsant effects of some quinolones were also evaluated in DBA/2 mice on seizures evoked by means of i.p. administration of imipenem. The present study demonstrated that the order of proconvulsant activity in our epileptic model was pefloxacin > enoxacin > ofloxacin > nalidixic acid > rufloxacin > norfloxacin > ciprofloxacin > cinoxacin > temafloxacin. 4. The relationship between the chemical structure and the proconvulsant activity of quinolone derivatives was studied. The relationship between the lipophilicity and the proconvulsant activity was also investigated. 5. Although the main mechanism for seizure potentiation cannot be easily determined potential drug interactions exist. It has been reported that imipenem and quinolones are all believed to increase excitation of the central nervous system by inhibition of GABA binding to receptors. 6. A slow clearance from the central nervous system and from the kidney may also occur following the concomitant administration of some quinolones and imipenem.

The in vitro activity of a new fluorquinolone, rufloxacin, was determined against both clinical isolates and standard strains of Legionella pneumophila, Chlamydia trachomatis, and Listeria monocytogenes and compared to that of ciprofloxacin, ofloxacin, and erythromycin. Among the antibacterials tested erythromycin was the most active. Rufloxacin inhibited the growth of L. pneumophila at concentrations in the range of 0.06-0.25 mg/l, that of C. trachomatis at concentrations in the range of 2-4, and that of L. monocytogenes at concentrations in the range of 1-2 mg/l. Rufloxacin demonstrated approximately the same activity as ciprofloxacin against C. trachomatis, but twice as less potency as ofloxacin and erythromycin against L. pneumophila, L. monocytogenes, and C. trachomatis, and twice as less potency as ciprofloxacin against L. pneumophila.

The multiple-dose pharmacokinetics of rufloxacin were investigated in 13 patients with biopsy-proven cirrhosis and in 5 healthy controls. Rufloxacin was administered once a day for 5 consecutive days, starting with a loading dose of 400 mg on day 1 and 200 mg on the subsequent days. Plasma and urinary drug concentrations were determined by high-performance liquid chromatography and a microbiological assay. A one-compartment model applied to the high-performance liquid chromatography data was used to calculate the pharmacokinetic parameters of rufloxacin. In the controls rufloxacin had a low plasma clearance (41 +/- 4 ml/min, mean +/- S.E.M.), a long half-life (30.1 +/- 3.9 hr), a large area under the plasma concentration vs. time curve (171 +/- 18 micrograms.hr/ml) and a low renal clearance (18 +/- 2 ml/min). No appreciable differences were observed in the pharmacokinetic parameters between patients with various degrees of liver-function impairment (modified Child-Pugh score ranging from 5 to 13). In these patients plasma clearance was slightly reduced (-32%), but this decrease was caused by a marked reduction in renal clearance (-65%) rather than nonrenal clearance, which remained unchanged (22 ml/min in cirrhotic patients vs. 23 ml/min in controls). A significant (p < 0.01) correlation was found between creatinine clearance and both rufloxacin renal clearance (r = 0.769) and rufloxacin plasma clearance (r = 0.681). The elimination half-life and the area under the plasma concentration vs. time curve were moderately increased in cirrhotic patients (+33% and +26%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

The pharmacokinetics of rufloxacin were investigated in normal subjects and in patients with various degrees of renal failure after the administration of a single oral 400-mg dose. Twenty-four subjects were classified by glomerular filtration rate (GFR) normalized for body surface area. Group 1 subjects had GFRs of > 80 ml/min, group 2 subjects had GFRs from 30 to 80 ml/min, group 3 subjects had GFRs from 8 to 29 ml/min, and group 4 subjects had GFRs of < 8 ml/min. The patients in group 4 were on continuous peritoneal dialysis or underwent hemodialysis 48 h after dosing. Plasma and urinary rufloxacin concentrations were determined by high-performance liquid chromatography. A two-compartment model was used to calculate rufloxacin pharmacokinetic parameters. Apparent total body clearance of the drug was linearly related to GFR (r = 0.696; P < 0.01). The elimination half-life increased proportionally with the severity of renal impairment, with values of 30 +/- 3, 36 +/- 5, and 44 +/- 3 h in groups 1, 2, and 3, respectively. In patients with moderate renal failure, dosage adjustment of rufloxacin is not needed. The rufloxacin dose interval should be prolonged to 48 h as the GFR falls below 30 ml/min/1.73 m2.

The efficacy and safety of rufloxacin once daily was compared with that of ofloxacin b.i.d. for therapy of complicated cystitis and upper urinary tract infections. Eighty-three patients were randomly assigned to receive rufloxacin as a loading dose of 400 mg on the first day, followed by 200 mg s.i.d., and 80 received ofloxacin 300 mg b.i.d. Both agents were administered orally for a median duration of eight days. Bacterial elimination rates after treatment were 90% for rufloxacin and 81% for ofloxacin. Half of the treatment failures occurred in patients with infections caused by uropathogens that became either less sensitive or resistant to the quinolones being studied. At a two-week follow-up, recurrences had not occurred in any of the rufloxacin patients and had occurred in 17% of the ofloxacin patients. Minor adverse reactions were reported by 12 and 13 patients, respectively. Rufloxacin once daily is as effective as ofloxacin b.i.d. for the treatment of complicated cystitis and upper urinary tract infections.

The antimicrobial activity of the new fluoroquinolone rufloxacin (MF 934) was evaluated by a standardized agar dilution method against recent clinical isolates of Salmonella typhi (67 strains) and Brucella melitensis (108 isolates). The results were compared with 5 other commercially available or investigational fluoroquinolones. All the isolates of S. typhi were inhibited by 1.0 mg/l of rufloxacin as compared to 4-8 mg/l for B. melitensis. Minimum inhibitory concentrations of rufloxacin against both S. typhi and B. melitensis were 4-16 times higher than those of other fluoroquinolones.

For rufloxacin MF961, ofloxacin and fleroxacin the inhibition of DNA synthesis, intracellular accumulation, optimum bactericidal concentration (OBC) and killing kinetics at the OBC for Enterobacteriaceae, Pseudomonas aeruginosa and staphylococci and induction of recA in Escherichia coli were determined. All agents had good activity against all the strains and inhibited DNA synthesis by 50% at concentrations correlating with the MIC. The maximum recA inducing concentrations after 60 min exposure to the quinolones in E. coli were 0.5 mg/L of rufloxacin, MF961, ofloxacin and 0.05 mg/L of fleroxacin. Accumulation of all quinolones was rapid; however, higher concentrations of all agents were accumulated within staphylococci than in Gram-negative bacteria. Rufloxacin was accumulated to higher concentrations in all bacteria than the other three agents. Laboratory mutants with decreased susceptibility to the four drugs were selected from each strain. All agents selected mutants with decreased susceptibility to quinolones alone, with phenotypes suggesting mutations in gyrA. Multiply-resistant mutants were also selected; however, as few had decreased expression of OmpF, the mutated gene is unlikely to be an allele of marA. All mutants had MICs > or = 2 mg/L, a typical breakpoint concentration for most quinolones.

Quinolones rapidly kill bacteria by two mechanisms, one that requires protein synthesis and one that does not. The latter, which is measured as lethal action in the presence of the protein synthesis inhibitor chloramphenicol, is enhanced by N-1 cyclopropyl and C-8 methoxy substituents, as seen with the highly lethal compound PD161144. In some compounds, such as levofloxacin, the N-1 and C-8 substituents are fused. To assess the effect of ring fusion on killing, structural derivatives of levofloxacin and PD161144 differing at C-7 were synthesized and examined with Escherichia coli . A fused-ring derivative of PD161144 exhibited a striking absence of lethal activity in the presence of chloramphenicol. In general, ring fusion had little effect on lethal activity when protein synthesis was allowed, but fusion reduced lethal activity in the absence of protein synthesis to extents that depended on the C-7 ring structure. Additional fused-ring fluoroquinolones, pazufloxacin, marbofloxacin, and rufloxacin, also exhibited reduced activity in the presence of chloramphenicol. Energy minimization modeling revealed that steric interactions of the trans -oriented N-1 cyclopropyl and C-8 methoxy moieties skew the quinolone core, rigidly orient these groups perpendicular to core rings, and restrict the rotational freedom of C-7 rings. These features were not observed with fused-ring derivatives. Remarkably, structural effects on quinolone lethality were not explained by the recently described X-ray crystal structures of fluoroquinolone-topoisomerase IV-DNA complexes, suggesting the existence of an additional drug-binding state.

Rufloxacin (MF-934) was prepared in one-pot synthesis in 61% yield by treatment of the 2,3,5-trifluoro-4-(4-methyl-1-piperazinyl)-benzoyl acetate, first with N,N-dimethylformamide dimethyl acetal, then with 2-aminoethanethiol, followed by cyclization and hydrolysis.

The presence of copper(II) in the micromolar range modulates the photodegradation rate of the fluoroquinolone Rufloxacin (RFX), both under air and in nitrogen saturated aqueous solution. The photodegradation rate of RFX under aerobic conditions decreases in the presence of metal ions, and no change in the nature of the photoproducts is observed. In anaerobic media, RFX photodegradation rate increases with increasing copper(II) concentration and the photoproducts distribution changes. Copper(II) inhibits formation of type II products of 2'-deoxyguanosine diagnostic of photosensitization mediated by singlet oxygen. The overall results provide a clear example demonstrating how a bio-compatible trace element influences efficiently not only the bioavailability of a drug but also its molecular mechanism of photodegradation and photosensitization.

Rufloxacin (RFX) is an antibacterial fluoroquinolone that exhibits UVA photosensitization properties. Photosensitization reactions lead to the formation of oxidative damage, mainly via singlet oxygen. Here we explore the phototoxic and photomutagenic potency of RFX using a panel of yeast ( Saccharomyces cerevisiae ) mutants affected in different DNA repair pathways. Yeast mutants provide a sensitive tool to identify the photodamage and the DNA repair pathways that cope with it. Cell viability test at increasing dose of UVA shows that both the DNA repair deficient and wild type cells are equally sensitive to RFX-induced photosensitization, demonstrating that phototoxic effect is not due to DNA injury. Photomutagenicity of RFX is evaluated by measuring the frequency of forward Can R mutations. The mutation induction is low in wild type cells. A high increase in mutation frequency is observed in strains affected in Ogg1 gene, compared to wild type and other base excision repair deficient strains. The mutation spectrum photomediated by RFX in wild type cells reveals a bias in favour of GC > TA transversions, whereas transition and frameshift mutations are less represented. Altogether data demonstrates that 8-oxo-7,8-dihydroguanine (8-oxoGua) is by far the major DNA damage produced by RFX photosensitization, leading to mutagenesis. We also explore the role played by DNA mismatch repair, translesion synthesis and post-replication repair in the prevention of mutagenic effects due to RFX exposure. In addition, we show that most of RFX photodegradation products are not mutagenic. This study defines the phototoxic and photomutagenic properties of antibacterial RFX and point out possible unwanted side effects in skin under sunlight.

The protective effects of rufloxacin againstStaphylococcus aureus-induced infections were compared with those of ciprofloxacin in the granuloma pouch model in the rat. Two strains with different in vitro sensitivity to the drugs were studied. Rufloxacin concentrations persisted longer than ciprofloxacin in the exudate in the pouch cavity and were about eight times higher. Equal doses of rufloxacin and ciprofloxacin had similar antibacterial activities. However, rufloxacin inhibitedStaphylococcus aureus bacterial growth significantly longer than did ciprofloxacin.

A high-performance liquid chromatographic method is described for the determination of a fluoroquinolone, rufloxacin, and its N-desmethyl metabolite in plasma, urine and bile. Samples are chromatographed on a poly(styrene-divinylbenzene) column, the eluate being monitored with a fluorescence detector. The method was validated and a detection limit of 10 ng/ml for both rufloxacin and its metabolite in all the biological matrices considered was found. The method was successfully applied in pharmacokinetic studies.