Concentrations of temafloxacin in serum and bronchial mucosa

Mechanism for the tissue distribution of grepafloxacin, a fluoroquinolone antibiotic, in rats

This study was carried out to investigate the most important factor(s) governing the tissue distribution of grepafloxacin (GPFX), a fluoroquinolone antibiotic, in rats. The tissue-to-blood concentration ratio (K(p)) of GPFX at steady state during constant infusion was highest in the lung, followed by the pancreas, kidney, and spleen. After bolus injection, GPFX was efficiently taken up by most of the organs examined, the uptake clearance other than the lung being almost blood flow-limited. Approximately 10% of the intravenously injected dose was rapidly trapped by the lung, but GPFX distribution rapidly decreased within 30 s due to the washout by the plasma flow. Thus, the higher distribution of GPFX to the lung compared with the other organs cannot be accounted for by a difference in its uptake or efflux. Subcellular fractionation after the infusion indicated that GPFX is primarily distributed to the organelle fractions in most organs, 60% of lung-associated GPFX being recovered in the nucleus and plasma membrane fraction. Such subcellular distribution in the lung was proportional to the phosphatidylserine (PhS) content of each fraction. The steady-state K(p) value in each tissue in vivo also correlated with the tissue content of PhS. GPFX preferentially binds to PhS, compared with other phospholipids, and this binding was inhibited by weakly basic drugs, such as quinidine, imipramine, and propranolol, that have also been reported to bind to PhS. The association of GPFX with PhS synthase transformants of Chinese hamster ovary (CHO-K1) cells depends on the PhS content of each cell line, this association being also inhibited by basic drugs. These results suggest that binding of GPFX to PhS is the major determinant of the high distribution of GPFX to the lung.

Comparative bronchoalveolar concentrations of ciprofloxacin and lomefloxacin following oral administration

In a comparative study, the concentrations of two fluoroquinolone antimicrobials, ciprofloxacin and lomefloxacin, were measured in serum, bronchial mucosal biopsies, epithelial lining fluid (ELF) and alveolar macrophages (AM). Thirty-four subjects received either ciprofloxacin 250 mg b.d. (17 subjects) or lomefloxacin 400 mg o.d. for 4 days prior to sampling by bronchoscopic bronchial biopsy and bronchoalveolar lavage. Both ciprofloxacin and lomefloxacin showed favourable accumulation in the sites of infection with bronchial biopsy concentrations of 1.6 and 1.7 times those of serum respectively; ELF concentrations of 2.1 and 1.9 times serum; and AM concentrations of 11.8 and 20.1 times serum respectively. The MIC90 for most of the common chest pathogens was reliably exceeded by both agents except for that of Streptococcus pneumoniae.

Comparative penetration of selected fluoroquinolones into respiratory tract fluids and tissues

Sputum samples are easy to obtain; however, their use in therapeutic decision making is not without problems. Today, with the availability of more sophisticated endoscopic procedures, it is possible to determine antimicrobial concentrations at various sites within the respiratory tract. Fiber-optic bronchoscopy makes it possible to obtain samples of bronchial mucosa, bronchial epithelial lining fluid (ELF), and alveolar macrophages (AMs). Antimicrobial concentration measurements from the bronchial mucosa, ELF, and AM may be better predictors of successful antimicrobial therapy than sputum samples. In general, fluoroquinolones penetrate well into lung tissue, including bronchial mucosa, ELF, and AM, resulting in concentrations higher than corresponding serum levels. Temafloxacin, a new fluoroquinolone, attains high bronchial concentrations that are well above the 90% minimal inhibitory concentration (MIC90) for many of the common respiratory pathogens, including Streptococcus pneumoniae (MIC90 = 0.5 micrograms/mL). Early clinical trials confirm the clinical efficacy and safety of temafloxacin in the treatment of many common respiratory tract infections. The penetration of temafloxacin into the bronchial mucosa, AM, and ELF along with its antimicrobial spectrum supports the use of temafloxacin against common respiratory pathogens, including S. pneumoniae.

Treatment of acute exacerbations of chronic bronchitis: state of the art

Effective treatment of acute bacterial exacerbations of chronic bronchitis (ABE) reduces the number of such exacerbations in such patients and may decrease or eliminate background symptoms and improve pulmonary function. The pathologic and physiologic abnormalities of the bronchial system in chronic bronchitis that predispose to bacterial infection probably include impaired mucociliary clearance, obstructed bronchioles, and bacterial infections of the bronchial epithelium. Exacerbations of bronchopulmonary symptoms are usually observed with ABE, although these symptoms are not unique to ABE. While culture and sensitivity testing is not usually required, microscopic examination of sputum is critical to determine the presence of bacterial infection. Bacteria in numbers significantly above the levels present when the patient's condition is stable and at least a doubling of the sputum neutrophil inflammatory level are essential criteria. Bacterial species observed with ABE include Haemophilus influenzae, Haemophilus parainfluenzae, Streptococcus pneumoniae, Moraxella catarrhalis, and Neisseria species, with a lesser incidence of Klebsiella and Pseudomonas species. One or more elements of background therapy for ABE should accompany antimicrobial therapy, for example, physiotherapy, bronchodilators, and so forth. Ampicillin is effective, safe, economical, and thus remains the drug of choice for ABE. Quinolones are an effective alternative when ampicillin cannot be tolerated or if organisms are resistant. Dosing is at the upper range of recommendations, and the chosen drug should be given for a 10-14-day regimen. Patients should be reevaluated if symptoms and physical findings do not return to baseline after 5-7 days.

Temafloxacin compared with ciprofloxacin in mild to moderate lower respiratory tract infections in ambulatory patients. A multicenter, double-blind, randomized study

The efficacy and safety of oral temafloxacin (600 mg) and ciprofloxacin (500 mg) twice daily for seven days were compared in patients with mild to moderate lower respiratory tract infections. Fifty-eight of 64 (91 percent) patients who received temafloxacin and 63 of 67 (94 percent) patients who received ciprofloxacin had clinical cure or improvement; bacteriologic cure occurred in 61 (95 percent) and 63 (94 percent), respectively. All 14 patients with pneumonia were clinically cured or improved and bacteriologically cured; 11 had complete resolution of roentgenographic evidence of pneumonia. Both quinolones eradicated most major respiratory pathogens. In the ciprofloxacin group, organisms persisted in three of seven Pseudomonas aeruginosa isolates and in one of eight Hemophilus parainfluenzae isolates; all these pathogens were eliminated with temafloxacin. Theophylline blood levels significantly increased by 25 percent in the ciprofloxacin group and decreased by 5 percent in the temafloxacin group. Adverse events, mostly dizziness, headache, and gastrointestinal effects, occurred in 43 percent of temafloxacin patients and in 31 percent of ciprofloxacin patients.