Photodegradation of fleroxacin injection: II. Kinetics and toxicological evaluation.

Photodegradation kinetics of fleroxacin were investigated in different injections. Five commercial formulations were analyzed before and after irradiation by determining residual volumes of fleroxacin with high-pressure liquid chromatography (HPLC), and different decomposition functions and models were obtained. Concentration levels of fleroxacin in injections caused the differences in photodegradation kinetics instead of ingredients. Influences of different pH values and presence of NaCl on photodegradation of fleroxacin were observed. Low pH value decreased the efficacy of photolysis and enhanced photostability of fleroxacin injections. Tentative structure of a new degradation product afforded was proposed. An acute toxicity assay using the bioluminescent bacterium Q67 was performed for fleroxacin injections after exposure to light. The research proved that fleroxacin was more photolabile in dilute injection, and acute toxicity of dilute injection increased more rapidly than that of concentrated injection during irradiation.

Establishment of an immunological detection method of fleroxacin by fluorescence-linked immunosorbent assay.

The direct and indirect competitive fluorescence-linked immunosorbent assay (FLISA and icFLISA) incorporating quantum dots (QDs) for the detection of fleroxacin (FLE) was established for the first time in this study. The monoclonal antibody specific for FLE was successfully conjugated with QDs after purification by the caprylic acid-ammonium sulphate method. The limits of detection of FLISA and icFLISA were 0.012 ng/mL and 0.006 ng/mL, respectively; IC50 were 0.32 ng/mL and 0.19 ng/mL; and the detection ranges were 0.012-24.490 ng/mL and 0.006-16.210 ng/mL. The recovery was 93.8%-112.4% and the coefficient of variation was below 11.75%. The fabricated FLISA and icFLISA are cost-effective, high sensitive and can be an alternative method in the detection of FLE residues.

First population pharmacokinetic analysis showing increased quinolone metabolite formation and clearance in patients with cystic fibrosis compared to healthy volunteers.

Understanding the pharmacokinetics in patients with cystic fibrosis (CF) is important for dosing. For antibiotics with extensive metabolism, however, a comparison of metabolite formation and elimination between patients with CF and healthy volunteers has never been performed via population modeling. We aimed to compare the population pharmacokinetics of fleroxacin and its N­oxide and demethyl metabolites between patients with CF and healthy volunteers. Our analysis included eleven adult patients with CF and twelve healthy volunteers who received 800 mg fleroxacin as a single oral dose followed by five doses every 24 h from a previously published study. All plasma concentrations and amounts in urine for fleroxacin and its metabolites were simultaneously modelled. The estimates below accounted for differences in body size and body composition via allometric scaling by lean body mass. Oral absorption was slower in patients with CF than in healthy volunteers. For fleroxacin, the population mean in patients with CF divided by that in healthy volunteers was 1.12 for renal clearance, 1.01 for linear nonrenal clearance, 0.83 for saturable exsorption clearance into intestine, and 0.81 for volume of distribution. The formation clearances of N­oxide fleroxacin and N­demethylfleroxacin were 0.520 L/h and 0.496 L/h in patients with CF; these formation clearances were 0.378 L/h and 0.353 L/h in healthy volunteers. Renal clearance in patients with CF divided by that in healthy volunteers was 1.53 for N­oxide fleroxacin and 1.70 for N­demethyl fleroxacin. Allometric scaling by lean body mass best explained the variability. While fleroxacin pharmacokinetics was comparable, both formation and elimination clearances of its two metabolites were substantially larger in patients with CF compared to those in healthy volunteers.

Formation of antigenic quinolone photoadducts on Langerhans cells initiates photoallergy to systemically administered quinolone in mice.

Quinolone antibacterial agents are well known to cause photoallergy as a side-effect. Murine photoallergy to fluoroquinolones is a T cell-mediated immune response, evoked either by systemic fluoroquinolone and subsequent exposure of skin to ultraviolet A light or by subcutaneous injection of fluoroquinolone-photomodified epidermal cells. In this photosensitivity, epidermal Langerhans cells may be photomodified initially with the drug and thus present photohaptenic moieties to sensitize and restimulate T cells. Although we have shown that Langerhans cells photocoupled in vitro with fluoroquinolones are capable of stimulating sensitized T cells, it remains unclear whether systemically given fluoroquinolone photomodifies Langerhans cells upon ultraviolet A irradiation of the skin and the Langerhans cells become photohapten-bearing, T cell-stimulatory cells. In a murine model of fleroxacin photoallergy induced by intraperitoneal injection of the drugs plus ultraviolet A irradiation of skin, we found that Langerhans cells as well as keratinocytes are photoderivatized with fleroxacin as demonstrated with a fluoroquinolone-specific monoclonal antibody. Langerhans-cell-enriched epidermal cells prepared from mice treated with fleroxacin and ultraviolet A induced proliferation of sensitized T cells, indicating that photomodified Langerhans cells are functional. There was an optimal range of ultraviolet A dose to quantitatively and qualitatively form fleroxacin-photomodified Langerhans cells, as excess ultraviolet A rather reduced the photoantigen-presenting capacity of Langerhans cells presumably because of drug phototoxicity. Our study suggests that Langerhans cells serve as photoantigen-presenting cells in drug photoallergy.

A randomized clinical trial to compare fleroxacin-rifampicin with flucloxacillin or vancomycin for the treatment of staphylococcal infection.

BACKGROUND: Oral combination therapy with fluoroquinolones plus rifampicin is a promising alternative to standard parenteral therapy for staphylococcal infections. METHODS: In a multicenter, randomized trial, we compared the efficacy, safety, and length of hospital stay for patients with staphylococcal infections treated either with an oral combination of a fluoroquinolone (fleroxacin) plus rifampicin or with standard parenteral treatment (flucloxacillin or vancomycin). Patients were included if cultures showed the presence of bacteremia or deep-seated infections with Staphylococcus aureus (104 patients) or catheter-related bacteremia due to drug-susceptible, coagulase-negative staphylococci (23 patients). RESULTS: The cure rate in the intention-to-treat analysis was 78% for the fleroxacin-rifampicin group (68 patients) and 75% for the standard therapy group (59 patients; 47 received flucloxacillin, and 12 received vancomycin); in the population of clinically evaluable patients (n=119), the cure rate was 82% and 80%, respectively; and in the population of microbiologically evaluable patients (n=103), the cure rate was 86% and 84%, respectively. Clinical and bacteriological failures after S. aureus infections were documented in similar proportions of patients. The median length of hospital stay after study entry was 12 days in the fleroxacin-rifampicin group, compared with 23 days in the standard treatment group (P=.006). More adverse events probably related to the study drug were reported in the fleroxacin-rifampicin group than in the standard therapy group (15 of 68 vs. 5 of 59 patients; P=.05). CONCLUSIONS: This study suggests that an oral regimen containing a fluoroquinolone plus rifampicin may be effective for treating staphylococcal infections, allowing earlier discharge from the hospital.

Safety of fleroxacin in clinical trials.

This article reviews the safety of fleroxacin in clinical trials. Data from 4,450 patients treated with oral fleroxacin and 650 treated with intravenous fleroxacin were analyzed. The overall rate of adverse reactions for patients treated with oral fleroxacin was 20% for those given 200 mg daily and 20% for those given a daily dose of 400 mg. The adverse reaction rate with the intravenous formulation was 20%. The most frequent adverse reactions involved the gastrointestinal tract (11%) and the central nervous system (9%). All events were reversible. Insomnia was the most commonly reported adverse event. The safety profile of fleroxacin was similar to that reported with other fluoroquinolones.

Pharmacokinetics of fleroxacin in renal impairment.

Fleroxacin is excreted primarily via the kidneys in its unchanged form, and therefore renal impairment has a major influence on the pharmacokinetics of this drug. This study examined the pharmacokinetics of oral and intravenous fleroxacin in patients with renal impairment. Patients with renal disease (mean glomerular filtration rate [GFR], 22 mL/min) and healthy subjects (mean GFR, 100 mL/min) received 400 mg of fleroxacin orally and 100 mg of fleroxacin intravenously in a crossover design. Serial blood samples and a complete urine collection were obtained for > or = 72 hours after dosing. Unchanged drug in plasma and urine was determined by reverse-phase high-performance liquid chromatography. Fleroxacin was well tolerated by all study participants. Renal impairment had no influence on the complete absorption of fleroxacin from the gastrointestinal tract, the maximal plasma concentration, and the steady-state volume of distribution (Vd-ss > 1 L/kg). However, systemic clearance in patients was significantly decreased (p < 0.05) to 44.4 mL/min compared with 87.1 mL/min in healthy subjects. This decrease could be ascribed to a reduction in renal clearance from 59.1 mL/min in healthy subjects to 8.8 mL/min in patients. Metabolic clearance was not reduced significantly. As a consequence of reduced clearance, the mean elimination half-life in patients increased from 13.6 hours to 21.4 hours and the area under the concentration-time curve from 87.0 mg.h/L to 170.5 mg.h/L. To avoid an unacceptable accumulation of fleroxacin in the body during multiple dosing, the following dose adjustment was recommended: patients with renal disease whose GFR is < 40 mL/min should receive the normal loading dose, i.e., 400 mg, but should receive maintenance doses that are reduced by 50%, i.e., to 200 mg.

Randomized double-blind trial of high- and low-dose fleroxacin versus norfloxacin for complicated urinary tract infection.

Patients were entered in a double-blind, placebo-controlled, multicenter study to compare low- and high-dose fleroxacin with norfloxacin for the treatment of complicated urinary tract infection (UTI). A total of 296 patients were enrolled; 102, 97, and 97 patients were randomized to receive 200 mg of fleroxacin (low-dose), 400 mg of fleroxacin (high-dose), both once daily, or 400 mg of norfloxacin twice daily, respectively, for 10 days. Of these patients, 101, 94, and 95 were included in the safety analysis, and 71, 61, and 58 in the efficacy analysis. The main reason for exclusion from the efficacy analysis was failure to isolate a pathogen at baseline. The groups were comparable with respect to demographics. In the low-dose fleroxacin group, 68 (96%) of 71 patients had bacteriologic cures (eight with superinfection), compared with 56 (92%) of 61 in the high-dose fleroxacin group (two with superinfection) and 52 (90%) of 58 in the norfloxacin group (four with superinfection). Escherichia coli was the most frequent isolate in all groups. In the low-dose fleroxacin group, clinical cure was recorded in 61 (86%) of 71, improvement in six, and failure in four. In the high-dose group, clinical cure was noted in 58 (95%) of 61 patients, improvement in two, and failure in one. In the norfloxacin group, 50 (86%) of 58 patients were clinically cured, four were improved, and four failed. Clinical adverse events were reported by 22 (22%) of 101, 36 (38%) of 94, and 19 (20%) of 95 patients in the low-dose fleroxacin, high-dose fleroxacin, and norfloxacin groups, respectively. Insomnia and nausea were reported most frequently in the fleroxacin groups, and nausea and headache were most common in the norfloxacin group. The efficacy and safety of low-dose fleroxacin are comparable to those of norfloxacin for treatment of complicated UTI.

Fleroxacin versus norfloxacin for oral treatment of serious urinary tract infections.

Fleroxacin, 400 mg once daily, and norfloxacin, 400 mg twice daily, both administered orally, were compared for the treatment of serious urinary tract infections (UTIs). In total, 301 patients from multiple centers who had serious UTIs were randomized to receive fleroxacin or norfloxacin in a double-blind study. The demographic parameters of the two groups were similar. A total of 190 patients were evaluable for efficacy, 94 in the fleroxacin group and 96 in the norfloxacin group. The reasons for exclusion from the efficacy analysis were not significantly different in the two groups, but more patients receiving fleroxacin were prematurely withdrawn from the study. The majority (134) of the diagnoses were complicated UTI, and the pathogens were primarily Enterobacteriaceae. The clinical responses were cure or improvement in 98% of the fleroxacin group and 92% of the norfloxacin group and failure in 2% of the fleroxacin group and 7% of the norfloxacin group. The bacteriologic results by infection were cure in 98% of the fleroxacin group and 89% of the norfloxacin group (including cure with superinfection in 4% of the fleroxacin group and 5% of the norfloxacin group) and failure in 2% of the fleroxacin group and 11% of the norfloxacin group. Adverse events were more common in the fleroxacin group and were mostly nausea, insomnia, and headache. Fleroxacin, 400 mg once daily, was as effective as norfloxacin, 400 mg twice daily, in eradicating UTIs but was associated with more adverse events.

A sequential study of intravenous and oral fleroxacin in the treatment of complicated urinary tract infection.

This study enrolled patients with complicated urinary tract infections (UTIs) in a trial to determine the efficacy and safety of sequential therapy with intravenous fleroxacin (first 3 days) followed by oral fleroxacin, for a total course of 7-14 days, both administered at a dosage of 400 mg once a day. We enrolled 68 patients with complicated UTIs or acute pyelonephritis, 32 of whom were evaluable for bacteriologic and clinical efficacy. The pathogens isolated included Escherichia coli, 15; enterococci, 9; miscellaneous, 15. Intravenous fleroxacin was given for a mean of 3.2 days, followed by oral fleroxacin for a mean of 5.3 days. A total of 27 patients were clinically cured (84%), two improved, and three failed. A total of 26 patients were bacteriologically cured (81%), and six failed (19%). The bacteria that were not eradicated included enterococci, 4; Staphylococcus epidermidis, 1; and Pseudomonas species, 1. One enterococcal isolate became resistant to fleroxacin. Four patients were bacteremic (E. coli, 3; Proteus mirabilis, 1); the pathogen was eradicated in all cases. Two patients developed urinary enterococcal superinfections. A total of 12 patients experienced 16 adverse reactions remotely, possibly, or probably related to fleroxacin (insomnia, 3; dizziness, 2; miscellaneous, 11). One patient had a grand mal seizure after aspirating gastric contents; the seizure was thought to be only remotely related to the study drug. Fleroxacin was discontinued in two patients because of adverse effects (phlebitis at intravenous access site, 1; anxiety and insomnia, 1). Only minor and asymptomatic laboratory abnormalities were observed. All clinical and laboratory abnormalities resolved with discontinuation of the study drug. Fleroxacin is a safe and effective antibiotic for sequential intravenous and oral treatment of acute pyelonephritis and complicated UTIs. Enterococci may be problematic pathogens, as reported with other fluoroquinolones.

Multicenter study of single-dose and multiple-dose fleroxacin versus ciprofloxacin in the treatment of uncomplicated urinary tract infections.

The clinical efficacy and safety of single-dose and multiple-dose fleroxacin were assessed and compared with those of ciprofloxacin in women with uncomplicated urinary tract infection (UTI) in this clinical study. This multicenter, randomized, double-blind, prospective study compared single-dose therapy with fleroxacin, 400 mg, with 7-day courses of fleroxacin, 200 mg once a day, and ciprofloxacin, 250 mg twice a day, in the treatment of uncomplicated symptomatic UTI in women at 18 centers in the United States. Of 961 patients enrolled, 316 were in the fleroxacin single-dose group, 321 in the fleroxacin 7-day group, and 324 in the ciprofloxacin group. Of these patients, 943 met the criteria for inclusion in the safety analysis and 556 met those for inclusion in the efficacy analysis. Bacteriologic cure rates at 5-9 days after therapy in patients evaluable for efficacy were 88%, 96%, and 96% in the single-dose fleroxacin group, 7-day fleroxacin group, and 7-day ciprofloxacin group, respectively (p < 0.05). Clinical cures occurred in 93.6%, 97.2%, and 98% of the groups, respectively (difference not significant). At 4-6 weeks after therapy, the rates of bacteriologic cure in the single-dose fleroxacin group, 7-day fleroxacin group, and 7-day ciprofloxacin group were 91%, 89%, and 93%, respectively (difference not significant). Adverse events were similar to those with other new quinolones and comparable among the treatment groups. Insomnia was more frequent in patients who received fleroxacin. Fleroxacin and ciprofloxacin as multidose regimens are similarly safe and effective in the treatment of uncomplicated UTI in women. Single-dose fleroxacin achieved a clinical response rate comparable to that achieved by the multiple-dose regimens, whereas its bacteriologic eradication rate was inferior.

Comparison of intravenous fleroxacin with ceftazidime for treatment of complicated urinary tract infections.

Intravenous fleroxacin, 400 mg once daily, was compared with intravenous ceftazidime, 0.5-2 g three times a day or 1-2 g twice a day, administered for 4-21 days for treatment of complicated urinary tract infections (UTIs) due to susceptible organisms. Fleroxacin also was tested in an uncontrolled trial. The trial was a multicenter, randomized, open-label study of adults with pyelonephritis or signs and symptoms of UTI and complicating factors. In the controlled trial, 474 patients were randomly assigned in a 2:1 ratio to receive fleroxacin (n = 320) or ceftazidime (n = 154). The microbiologic criterion for diagnosis of UTI was the isolation of > or = 10(5) colony-forming units (CFU) of pathogenic bacteria/mL of urine. The efficacy analyses included 165 fleroxacin-treated and 82 ceftazidime-treated patients in the controlled trial and 97 patients in the uncontrolled trial. In the controlled trial, 317 fleroxacin-treated and 150 ceftazidime-treated patients were included in the safety analysis. In the controlled trial, the respective rates of bacteriologic cure (< or = 10(4) CFU/mL of urine 48-96 hours after first dose and 2-5 days posttherapy) were 94% (confidence interval [CI], 89-97%) and 95% (CI, 88-99%) in the fleroxacin and ceftazidime groups, and those of clinical cure were 86% (CI, 80-91%) and 89% (CI, 80-95%). Rates of clinical and bacteriologic cure in the uncontrolled study were 95%. In the controlled trial, 9% of the patients in each treatment group experienced one or more adverse events possibly or probably related to the study drug. The percentage of patients terminating therapy prematurely was higher in the fleroxacin than in the ceftazidime group. Once-daily dosing with 400 mg of intravenous fleroxacin was equivalent to a standard multidose regimen with respect to rates of bacteriologic and clinical cure in the treatment of complicated UTI.

A pilot study of oral fleroxacin given once daily in patients with bone and joint infections.

The object of this open-label, noncomparative, multicenter study was to evaluate the efficacy and safety of 400 mg of fleroxacin administered orally once daily for 2-12 weeks to patients with bone and joint infections (osteomyelitis, septic arthritis, and prosthetic joint infection). A total of 90 adult patients (56 men and 34 women) were treated at 11 centers. Patients returned on days 5-9 of treatment, subsequently every 2 weeks during treatment, and 0-3 days and 28-42 days (compulsory follow-up) after treatment for assessment of bacteriologic, clinical, and safety parameters. A total of 19 patients (13 with osteomyelitis, 5 with septic arthritis, and 1 with prosthetic joint infection) were bacteriologically evaluable. Staphylococcus aureus was the predominant pathogen isolated in all evaluable infections. Of the 13 patients with osteomyelitis, 11 (85%) were bacteriologically cured and 10 (77%) were clinically cured. Three of the five patients with septic arthritis and the single patient with a prosthetic joint infection were both bacteriologically and clinically cured. Clinical adverse events related to fleroxacin were reported by 25 (28%) of the 90 patients. Most of these events involved the digestive system (primarily constipation and nausea) and the central nervous system (primarily insomnia and headache). The majority of these were of mild or moderate intensity and occurred during the first 2 weeks of treatment. Adverse events led to premature discontinuation of treatment in seven patients. Bone and joint infections continue to represent a therapeutic challenge. Treatment is based mainly on surgical procedures (drainage, sequestrectomy, ablation of implants, and implantation of cement impregnated with antibiotics) and on parenteral administration of antibiotics, requiring hospitalization of the patient. Fleroxacin, a new fluoroquinolone, has proven in vitro activity against bacteria involved in bone and joint infections. Its oral, once-daily administration, which eliminates hospitalization and its attendant costs, makes this drug an effective outpatient treatment of bone and joint infections.

Multicenter trial of fleroxacin versus ceftriaxone in the treatment of uncomplicated gonorrhea.

In a multicenter, randomized, open, comparative trial, patients with uncomplicated gonorrhea were treated with 400 mg of oral fleroxacin or 250 mg of intramuscular ceftriaxone. A total of 458 men and 447 women were enrolled. Of these, 312 men (68%) and 245 women (55%) were evaluable for efficacy. The treatment groups were demographically similar. Among evaluable men, fleroxacin eradicated 154 of 155 (99%; 95% confidence interval [CI]: 98.1-100%) urethral and 2 of 2 pharyngeal infections, while ceftriaxone eradicated 156 of 156 (95% CI: 99.4-100%) urethral and 5 of 5 pharyngeal infections. Among evaluable women, fleroxacin eradicated 127 of 128 (99%; 95% CI: 97.7-100%) cervical, 20 of 20 anorectal, 16 of 16 urethral, and 7 of 7 pharyngeal infections, while ceftriaxone eradicated 108 of 108 (95% CI: 99.1-100%) cervical, 24 of 24 anorectal, 25 of 25 urethral, and 9 of 9 pharyngeal infections. Adverse events were reported by 68 (16%) of 426 subjects in the fleroxacin group and 20 (5%) of 380 in the ceftriaxone group (p < 0.0001). The most common adverse events reported by the patients who received fleroxacin were nausea (5%), headache (3%), and vaginitis (3%). One patient had severe vomiting, 19 participants had adverse reactions classified as moderate, and 48 patients had mild adverse reactions. Fleroxacin was highly effective in the treatment of uncomplicated gonorrhea and represents an oral alternative to ceftriaxone. Adverse events were more common with fleroxacin than with ceftriaxone.

Fleroxacin in the treatment of chancroid: an open study in men seropositive or seronegative for the human immunodeficiency virus type 1.

Fleroxacin was prescribed to treat both HIV-negative and HIV-positive men with proven chancroid in an open study. HIV-negative men were treated with a single 400-mg dose of fleroxacin, and HIV-positive men were treated with 400 mg daily for 5 days. Three of the 58 evaluable HIV-negative men were clinical and microbiologic failures, and two of the 22 evaluable HIV-positive men had persisting infection with Haemophilus ducreyi. Both regimens were well tolerated. Fleroxacin is an acceptable alternative to existing treatment regimens for chancroid in men.

Fleroxacin versus amoxicillin in the treatment of acute exacerbation of chronic bronchitis.

The objective of this double-blind, multicenter study was to compare the efficacy and safety of oral fleroxacin, 400 mg once daily for 7 days, with amoxicillin, 500 mg administered every 8 hours for 7 days, in the treatment of acute exacerbation of chronic bronchitis. Adult male or female inpatients or outpatients were included. Patients gave informed consent and underwent a physical examination. Appropriate sputum specimens were collected, gramstained, and cultured before and 3-9 days after therapy. Complete blood count, serum chemistry, and urinalysis were performed before and 3-9 days after therapy. Of the 625 enrolled patients, 286 (148 in the fleroxacin group and 138 in the amoxicillin group) were evaluable for efficacy. The rate of bacteriologic cure was 96% (142 of 148) among patients in the fleroxacin group and 83% (114 of 138) among patients in the amoxicillin group, showing a statistically significant superiority for fleroxacin. The rate of clinical cure in the patients evaluable for this parameter was 90% (131 of 145) in the fleroxacin group and 82% (111 of 136) in the amoxicillin group. The differences were not significant, but the trend supported the bacteriologic results. Adverse clinical events related to the trial medication were reported by 61 (19%) of 313 patients receiving fleroxacin and by 27 (9%) of 310 patients treated with amoxicillin. The rates of bacteriologic cure and clinical success for fleroxacin were higher than those for amoxicillin. While the overall rate of adverse events was higher in the fleroxacin group, the proportions of patients with severe adverse events was higher in the fleroxacin group, the proportions of patients with severe adverse events were similar in the two groups. Most of the reported events were not serious or severe and were generally well tolerated, as reflected by the low proportion of premature withdrawals for this reason.

Intravenous fleroxacin versus ceftazidime in the treatment of acute nonpneumococcal lower respiratory tract infections.

Fleroxacin, administered intravenously at a dosage of 400 mg once a day, was compared with ceftazidime, 0.5-2 g three times daily or 1-2 g twice daily, administered for 4-21 days, for treatment of nonpneumococcal lower respiratory tract infections. A total of 319 patients were enrolled and randomized to receive treatment with fleroxacin or ceftazidime in a 2:1 ratio. Of those enrolled, 68 fleroxacin- and 49 ceftazidime-treated patients were included in the efficacy analysis. The most common diagnoses were pneumonia or pneumonitis (47% of the fleroxacin group and 57% of the ceftazidime group) and exacerbation of chronic bronchitis (38% and 33%, respectively). In the fleroxacin group, 59 (88%) of 67 patients were bacteriologic cures, and in the ceftazidime group, 40 (90%) of 49 were bacteriologic cures. It could be concluded with 95% confidence that the bacteriologic outcomes, by infection, for the two groups were equivalent (fleroxacin, 88%; ceftazidime, 90%). The rates of clinical cure were 59 (88%) of 67 for the fleroxacin group and 40 (82%) of 49 in the ceftazidime group, but since the 95% confidence limit around the between-group difference was greater than the stipulated +/- 15%, it could not be concluded that the outcomes were equivalent. The percentage of patients who experienced adverse clinical or laboratory events was similar in the two treatment groups (12% and 13%). The bacteriologic outcomes, by infection, were equivalent for the two treatment groups. Protocol requirements permitting a determination of equivalence of the outcomes for clinical cure were not met, although the rates were similar.

Open trial of oral fleroxacin versus amoxicillin/clavulanate in the treatment of infections of skin and soft tissue.

In a multicenter, prospective, randomized trial, fleroxacin was compared with amoxicillin/clavulanate potassium (AMX/CP) for the treatment of infections of skin and soft tissue. Fleroxacin was given at a dosage of 400 mg once daily, and AMX/CP was given at a dosage of 500 mg/125 mg three times a day. Each was administered for 4-21 days. Adult patients with the clinical diagnosis of skin or soft tissue infections were eligible for enrollment. Patients were randomized in a 2:1 ratio. A total of 191 patients were enrolled; 126 took fleroxacin, and 65 took AMX/CP. Of these patients, 42 in the fleroxacin group and 26 in the AMX/CP group were evaluable for both clinical and bacteriologic efficacies. Patients with abscesses comprised the largest single category in each group. Principle reasons for exclusion included: patients lost to follow-up (17 [13%] fleroxacin, 12 [18%] AMX/CP); failure to isolate a causative pathogen (19 [15%] fleroxacin, 9 [14%] AMX/CP); and resistance to study drug (11 [9%] fleroxacin, 2 [3%] AMX/CP). Staphylococcus aureus was the most commonly isolated pathogen. Streptococcus group A, Staphylococcus coagulase-negative, Escherichia coli, and Proteus species, in decreasing order, were the next most common pathogens. Clinical and bacteriologic efficacy was excellent in both groups, with a cure rate of > or = 90%. There were two bacteriologic failures in each group. Patients taking fleroxacin complained of slightly more adverse events, which involved primarily the digestive and central nervous systems. The rate of withdrawal from the study because of adverse events was 4% in both groups. Fleroxacin, 400 mg given once daily, is safe and as effective as AMX/CP in the treatment of skin and soft tissue infections in adults.

Treatment of acute bacterial diarrhea: a multicenter international trial comparing placebo with fleroxacin given as a single dose or once daily for 3 days.

This study was designed to test the efficacy of 400 mg fleroxacin given orally as a single dose or once daily for 3 days against acute bacterial diarrhea. A group of 508 adults with acute diarrhea were entered into a randomized, double-blind, placebo-controlled, multicenter trial. Patients were examined and asked about numbers of liquid stools daily for 3 days and at 5 days after start of treatment. Repeat stool samples were obtained for culture on days 3 and 5 after start of treatment. A total of 332 patients showed stool cultures positive for bacterial pathogens sensitive to fleroxacin and completed their treatments. Patients treated with fleroxacin, both single-dose and 3-day regimens, showed faster clinical improvement than did placebo-treated patients, as shown by earlier cessation of diarrhea (p < 0.001) and reduction in mean number of loose stools per day on days 2, 3, and 5 after start of therapy (p < 0.05). Bacteriologic efficacy was demonstrated by negative stool cultures for initial pathogens on days 3 and 5 after start of therapy in 94% of patients treated with single doses of fleroxacin and in 93% of patients treated with three doses of fleroxacin as compared with 57% of patients treated with placebo (p < 0.001). Patients with cholera, shigellosis, and infections due to Vibrio parahaemolyticus showed both clinical and bacteriologic responses to fleroxacin treatment, whereas patients with salmonellosis showed only bacteriologic responses. The good overall clinical and bacteriologic responses of most patients with acute bacterial diarrhea of fleroxacin indicate that this convenient single-dose therapy should be advantageous for empiric treatment of certain diarrheal illnesses.

Fleroxacin clinical pharmacokinetics.

Fleroxacin is a new member of the class of fluoroquinolones. The drug has good activity (i.e. minimum inhibitory concentrations at less than 2 mg/L against 90% of strains) against a wide range of Gram-positive and Gram-negative bacteria. High performance liquid chromatography is used to determine concentrations of fleroxacin and its metabolites in biological fluids. Absorption of orally ingested drug is rapid as the peak plasma concentration of approximately 5 mg/L is reached in 1 to 2h after a single dose of 400mg. The systemic availability is close to 100%. Fleroxacin is poorly bound to plasma proteins (23%) and exhibits excellent tissue distribution. Renal clearance accounts for 60 to 70% of elimination. The drug is metabolised to form antimicrobially active N-demethyl-fleroxacin and inactive N-oxide-fleroxacin. In multiple dose studies the accumulation ratio of a once-daily dosage regimen is about 1.3, as predicted from the elimination half-life of 10 to 12h. Compared with ciprofloxacin, fleroxacin has a greater systemic availability and a longer half-life. Fleroxacin concentrations are higher in elderly patients, but further studies are needed to establish whether a dosage reduction should be recommended for this age group. In patients with renal disease dosage adjustment is recommended since a decreased renal clearance of fleroxacin leads to a significant prolongation of the elimination half-life. Fleroxacin is only poorly eliminated by peritoneal dialysis or haemodialysis. The most important drug-drug interaction is a decrease in systemic availability of fleroxacin after ingestion of aluminium- or magnesium-containing antacids. There is no evidence of a significant interaction between fleroxacin and theophylline. Only limited data are available on adverse reactions of fleroxacin. The most important adverse effects appear to be photosensitivity and a dose-dependent incidence of central nervous system reactions including sleep disorders.