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

Feasible spectrofluorimetric approach for the ultrasensitive determination of lomefloxacin based on synergistic effects of micellization and metal complexation

The purpose of the present work was to establish a fast and convenient strategy for lomefloxacin analysis using a fluorimetric approach. The methodology was based on the complex formation of the drug with aluminum ion to give a product having high fluorescence. Adding sodium dodecyl sulfate led to further boosting the intensity of fluorescence which was recorded at 429 nm after excitation at 332 nm. The relationship of emission intensity with lomefloxacin concentration was linear at 10-130 ng mL^-1 with a correlation coefficient of 0.9996. The quantitation limit was 11.4 ng mL^-1 and detection limit was 3.8 ng mL^-1. The reaction conditions were carefully studied which included the pH, buffer type, its concentration, the type and concentration of surfactant and the diluting solvent. The method was utilized to quantify the aforementioned drug in tablet formulations and in real human plasma with high accuracy and reliability.

The incidence of collagen-associated adverse events in pediatric population with the use of fluoroquinolones: a nationwide cohort study in Taiwan

BACKGROUND

To evaluate the safety of using fluoroquinolones in pediatric population in Taiwan.

METHODS

Patients aged 0~18 years old with fluoroquinolones prescriptions ≥5 consecutive days during year 2000 to 2013 were selected from the National Health Insurance Research Database, 4-time case number were selected as controls. We evaluated the patient's outcome after the use of fluoroquinolones by reviewing a newly diagnosis of the following collagen-associated adverse events by International Classification of Diseases, Ninth Revision, Clinical Modification codes, covering tendons rupture, retinal detachments, gastrointestinal tract perforation, aortic aneurysm or dissection.

RESULTS

Of the enrolled patients (n = 167,105), collagen-associated adverse effects developed in 85 cases (0.051%) in 6-month tracking, including 0.051% in the fluoroquinolones study cohort (17 in 33,421) and 0.051% (68 in 133,684) in the fluoroquinolones free comparison cohort. The crude hazard ratio for collagen-associated adverse events in the fluoroquinolones group was 0.997 (0.586-1.696; p = 0.990). After adjusting for age, sex, catastrophic illness, low-income household, seasons, levels of urbanization, and healthcare, the corrected hazard ratio in 6-month tracking with FQs was 1.330 (95% CI; 0.778-2.276; p = 0.255).

CONCLUSIONS

There is no significant difference of collagen-associated adverse effects between fluoroquinolones group and fluoroquinolones free group from our data. We propose that fluoroquinolones for pediatric population in clinical practice may be not so harmful as previous references reported.

The UVR wavelength dependence for lomefloxacin photosensitization of human skin

Lomefloxacin is a new fluoroquinolone with effective broad-spectrum antimicrobial activity. However, in common with other structurally related drugs, skin photosensitization reactions have been reported. The wavelength dependence for such photosensitization has been investigated on the previously unexposed buttock skin of 12 normal healthy human volunteers of skin types I and II. Using geometric square root of 2 dose increments, baseline 24 h minimal erythema doses were assessed at 300, 320, 330, 340, 350 and 360 nm, and with broad-band UVA. In addition, dose-response curves were constructed for erythema as measured by a reflectance device. Subjects received single daily oral doses of 400 mg lomefloxacin at specified times for 4 days. At 2 h after the final dose, new areas of buttock skin were irradiated to assess changes in minimal erythema dose and erythema dose-response. Convolution of the erythema action spectra obtained pre- and on-drug with a terrestrial solar spectrum showed that, although the UVA sensitivity on-drug was enhanced, most of the erythemally effective solar energy was still in the UVB region. An action spectrum derived for lomefloxacin skin photosensitization showed peak activity at 320 nm, the same spectral region as that for maximal absorption of the drug. There was no evidence of skin photosensitization at 300 nm.

Interaction study of lomefloxacin and ciprofloxacin with omeprazole and comparative pharmacokinetics

To assess whether or not concomitant omeprazole treatment influences the pharmacokinetics of lomefloxacin and ciprofloxacin, a randomized, double-blind four-way-crossover study was performed. Another objective was to compare the pharmacokinetics of lomefloxacin and ciprofloxacin. Twelve healthy volunteers participated. On days 1 to 4 of each study period, each of them took 20 mg of omeprazole or a placebo orally, and on day 4, each took 400 mg of lomefloxacin or 500 mg of ciprofloxacin orally. Blood and urine samples were collected and assayed for the quinolones by high-pressure liquid chromatography. The mean peak concentrations in plasma (Cmax) and the areas under the curves (AUC), respectively, of lomefloxacin and ciprofloxacin, respectively, after prior treatment with placebo were 2.88 +/- 0.73 (mean +/- standard deviation) as against 2.60 +/- 0.76 micrograms/ml and 24.9 +/- 3.13 as against 11.9 +/- 1.89 micrograms.h/ml, and 72.4% +/- 5.10% as against 36.1% +/- 7.50% of the doses of lomefloxacin and ciprofloxacin, respectively, were recovered from the urine. None of the pharmacokinetic parameters differed significantly after prior treatment with omeprazole compared with placebo. The Cmax of lomefloxacin was not significantly higher than that of ciprofloxacin, but lomefloxacin's AUC reached twice that of ciprofloxacin because of its significantly longer half-life in plasma (6.68 +/- 1.94 as against 4.15 +/- 0.92 h, respectively, P < or = 0.01). Concomitant therapy with omeprazole did not alter the pharmacokinetics of lomefloxacin or ciprofloxacin in these single-dose studies.