Comparative in vitro activity of lomefloxacin, a difluoro-quinolone

Uncomplicated urinary tract infections: lomefloxacin versus trimethoprim/sulphamethoxazole

Data were collected from 14 French centres which participated in a randomized study to compare the safety and efficacy of 400 mg lomefloxacin taken orally once daily by 62 patients with 160/800 mg trimethoprim/sulphamethoxazole (TMP/SMX) taken orally twice daily by 64 patients with uncomplicated urinary tract infections. Most patients were infected with Escherichia coli at baseline (72.4% in the lomefloxacin group and 69.0% in the TMP/SMX group) and all patients were treated for 5 days. At 5-9 days post-treatment, lomefloxacin had eradicated the causative organism of infection in 100% of evaluable patients treated with lomefloxacin compared with 86.7% of those treated with TMP/SMX. At 4-6 weeks post-treatment, there were no marked differences in eradication rates between the two treatment groups: 83.3% and 80.0% for the lomefloxacin and TMP/SMX groups, respectively. Clinical cure rates showed no marked differences between treatment groups at 5-9 days or at 4-6 weeks post-treatment. At 5-9 days post-treatment, lomefloxacin achieved a clinical cure rate of 78.6% compared with 86.7% for TMP/SMX evaluable patients. At 4-6 weeks post-treatment, the clinical cure rates were 66.7% and 86.7% for the evaluable lomefloxacin- and TMP/SMX-treated patients, respectively. Both treatment regimens were well tolerated with a low incidence of adverse events. In conclusion, once-daily oral dosing with lomefloxacin is a safe and efficacious alternative to twice-daily dosing with TMP/SMX in the treatment of uncomplicated urinary tract infections.

In vitro activity of lomefloxacin and other antimicrobials against bacterial enteritis pathogens

Lomefloxacin is a new, difluoroquinolone. In this study, the in vitro activity of lomefloxacin against clinical isolates of a variety of bacterial species associated with acute diarrheal disease was determined and compared with that of ciprofloxacin, ofloxacin, amoxicillin, sulphamethoxazole, trimethoprim, tetracycline, and chloramphenicol. Bacterial isolates were obtained from different geographical areas, including Western Europe and the United Kingdom, Southern Europe, Africa, the Middle East, South and Southeast Asia, and South America, and were included to reflect the range of susceptibility seen throughout the world. Minimum inhibitory concentrations (MICs) were determined using an agar incorporation technique in Mueller-Hinton medium supplemented when necessary with saponin-lysed horse blood at a final concentration of 10% vol/vol. Lomefloxacin was highly active against all the species examined which included Salmonella spp., Shigella spp., Escherichia coli enterotoxigenic [(ETEC), enteroinvasive (EIEC), and enteropathogenic (EPEC) strains], Yersinia enterocolitica, Campylobacter jejuni, Vibrio spp., and Aeromonas hydrophila, with all isolates inhibited by 1 mg/L or less. This activity was similar to ofloxacin and slightly less than that of ciprofloxacin. By contrast, many of the isolates were resistant to one or more of the other, unrelated animicrobials. No cross-resistance between lomefloxacin and any of the nonfluoroquinolone antimicrobials examined in the study was observed.

Multiple-dose pharmacokinetics of lomefloxacin: rationale for once-a-day dosing

Six dosage regimens of oral lomefloxacin, a new difluorinated quinolone, were given to healthy volunteer subjects for 7 days in a randomized, placebo-controlled trial to evaluate pharmacokinetics and tolerability and to determine the optimum dosage schedule. Single daily doses of lomefloxacin up to 800 mg and multiple doses up to 600 mg twice daily (1,200 mg/day) were well tolerated. At all dose levels and schedules, lomefloxacin was well absorbed and achieved peak plasma concentrations approximately 1 hour after administration. Urine concentrations were approximately 100 times the plasma concentrations. Elimination half-lives of 7-8 hours were found for all dosage regimens. Steady-state was achieved on the second day of dosing. Little accumulation was observed. A 400 mg oral dose provided a mean peak plasma concentration of 3.43 micrograms/mL, and trough concentrations at steady state that were above the minimum inhibitory concentration for 90% (MIC90) of most common Enterobacteriaceae. The 400 mg dose produced a urine concentration of greater than 80 micrograms/mL during the 12- to 24-hour period after the dose, thus exceeding the MIC90 for clinical isolates such as Pseudomonas aeruginosa, Serratia marcescens, and methicillin-susceptible and -resistant Staphylococcus aureus. There was good agreement between the results of this study and previously reported single-dose data. In summary, lomefloxacin's rapid absorption, long half-life, and high sustained plasma and urine concentrations should permit effective once-daily administration in many clinical situations.

Fluoroquinolone (Lomefloxacin) International Surveillance Trial: a report of 30 months of monitoring in vitro activity

The antimicrobial activity and spectrum of lomefloxacin were assessed by standardized disk diffusion methods in 36 countries. More than 500,000 facultative organisms were tested during the first 30 months of a 3-year monitoring interval. Lomefloxacin demonstrated inhibition (zones greater than or equal to 19 mm) of greater than 90% of Enterobacteriaceae, greater than 99% of Moraxella (Branhamella) catarrhalis, greater than 98% of Haemophilus spp., and 91% of Staphylococcus aureus strains. Pseudomonas spp., especially Pseudomonas aeruginosa (18% resistance), were considered moderately susceptible, as were most strains of streptococci and enterococci. Some variation of national/regional fluoroquinolone resistance rates was observed, using lomefloxacin as an index or indicator drug, with the highest numbers of resistant strains being isolated in France. However, these data demonstrated a wide spectrum of lomefloxacin activity in all nations monitored.

Lomefloxacin: microbiologic assessment and unique properties

In comparative studies, lomefloxacin, a new difluorinated quinolone, exhibits broad antibacterial activity in vitro, similar or superior to that of other quinolones (enoxacin, ofloxacin, pipemidic acid, nalidixic acid, and norfloxacin) but less than that of ciprofloxacin. Lomefloxacin inhibited Neisseria gonorrhoeae, Moraxella (Branhamella) catarrhalis, Haemophilus influenzae, Pseudomonas aeruginosa, Staphylococcus aureus, and the majority of aerobic gram-negative rods, including nosocomial isolates, at concentrations readily achievable in biologic fluids and tissues. Lomefloxacin was less active against obligate anaerobes and streptococci. Organisms resistant to methicillin, penicillin, or the aminoglycosides were susceptible to lomefloxacin. No significant lomefloxacin resistance was identified in 18 countries in which in vitro studies were conducted, with the exception of a small number of strains tested in France. The frequency with which spontaneous single-step resistance to lomefloxacin develops in vitro is low.

The U.S. clinical experience with lomefloxacin, a new once-daily fluoroquinolone

Lomefloxacin is a new fluoroquinolone antimicrobial agent that has undergone extensive worldwide clinical evaluation. This report summarizes the safety and efficacy of lomefloxacin in the treatment of uncomplicated urinary tract infections, complicated urinary tract infections, acute exacerbations of chronic bronchitis, and for prophylaxis during urinary tract surgery. The clinical data presented are an overview of all clinical studies conducted in the United States to date. The results have been derived from multiple studies in which patients received lomefloxacin or a comparative agent in either blinded or open-label studies. During the course of the clinical program in the United States, lomefloxacin has been compared with oral norfloxacin, ciprofloxacin, and cefaclor, as well as parenteral cefotaxime. In all instances, the once-daily oral administration of lomefloxacin was either equally effective or statistically significantly superior in clinical and/or bacteriologic efficacy to these comparative agents. In addition, the comparators were administered either two or three times per day, except in the surgical prophylaxis studies, in which single doses of each antibiotic were administered preoperatively. These results attest to the value of the convenience and simplicity of the oral dosing regimen for lomefloxacin. During the course of the clinical program, lomefloxacin was well tolerated, with most adverse events of mild to moderate severity. In general, the incidence of adverse events for patients and subjects receiving lomefloxacin was comparable to that observed in patients treated with comparator drugs. The most common adverse events were related to the gastrointestinal tract (nausea and diarrhea), the skin and appendages (photosensitivity), and the central nervous system (dizziness and headache). A sub-analysis of adverse events in the respiratory studies demonstrated that concomitant administration of lomefloxacin and theophylline does not increase the incidence of adverse events when compared to lomefloxacin alone. An additional sub-analysis also showed that the incidence of adverse events in elderly patients was similar to that in younger patients. The results of the U.S. clinical program indicate that lomefloxacin administered orally once daily is effective and well tolerated in a variety of infections of bacterial origin.

A multicenter comparison of oral lomefloxacin versus parenteral cefotaxime as prophylactic agents in transurethral surgery

This report presents the pooled results from two randomized trials of lomefloxacin and cefotaxime used as prophylaxis in patients undergoing transurethral surgical procedures. A total of 499 patients were enrolled at seven centers in the United States. Patients received either 400 mg of lomefloxacin orally 2-6 hours prior to surgery, or 1 g of cefotaxime intravenously or intramuscularly 30-90 minutes preoperatively. Patients undergoing simple cystoscopy or retrograde pyelograms were not eligible for inclusion. Urine cultures were obtained prior to surgery, 24 hours post-surgery, prior to catheter removal, and 3-5 days post operatively. Treatment failure was defined as isolation of greater than or equal to 10(5) colony-forming units (CFU)/mL of pathogenic bacteria from any post-surgical urine culture. Lomefloxacin was successful in preventing post operative infections in 204 of 207 evaluable patients (98.6%); there were three prophylactic failures. Cefotaxime was successful in 196 of 206 (95.1%) evaluable patients; 10 were prophylactic failures. Lomefloxacin concentrations were measured simultaneously in serum and in samples of prostate tissue from 29 patients undergoing transurethral resection of the prostate. Lomefloxacin prostate concentrations were 1.0-22.3 micrograms/g, with a mean of 5.0 micrograms/g. The average tissue:plasma ratio was 2.0. The safety profile of the two study drugs was excellent, and both were well tolerated. Adverse events were reported by 12.7% of the patients treated with lomefloxacin and 13.8% of those treated with cefotaxime. The majority of events were mild and required no treatment.

Lomefloxacin. A review of its antibacterial activity, pharmacokinetic properties and therapeutic use

The antibacterial efficacy of oral lomefloxacin has been investigated in a wide variety of infections, including respiratory and uncomplicated and complicated urinary tract infections, obstetric, gynaecological, joint, skin, oral, ear, nose, throat and eye infections. It has also been used as an otic solution in patients with otitis media and as an ophthalmic solution in the treatment of eye infections. In clinical trials its efficacy is equivalent to that of other quinolones and it is at least as effective as other antibacterial drugs ordinarily used in these infections. Lomefloxacin offers certain advantages compared with other quinolone antibacterial drugs in that it may be conveniently administered once daily and theophylline dosage adjustment does not appear to be necessary in patients receiving this bronchodilator concomitantly. Thus, orally administered lomefloxacin should prove a useful broad spectrum antibacterial drug for a wide variety of clinical infections.

In vitro susceptibilities of Bordetella pertussis and Bordetella parapertussis to seven fluoroquinolones

The in vitro susceptibilities of Bordetella pertussis and Bordetella parapertussis to seven fluoroquinolones were assessed by the agar dilution method. Ciprofloxacin and temafloxacin were the most active compounds (MIC for 90% of isolates tested [MIC90], 0.06 microgram/ml), while enoxacin and pefloxacin were the least active (MIC90, 0.5 microgram/ml). Fleroxacin, lomefloxacin, and ofloxacin showed intermediate activities (MIC90s, 0.125 to 0.25 microgram/ml). These results suggest a possible role for the fluoroquinolones in the treatment of pertussis, at least in adult patients.