Highlights on the appropriate use of fluoroquinolones in respiratory tract infections

Immunobiological efficacy and immunotoxicity of novel synthetically prepared fluoroquinolone ethyl 6-fluoro-8-nitro-4-oxo-1,4-dihydroquinoline-3-carboxylate

The present study examined the cytotoxicity, anti-cancer reactivity, and immunomodulatory properties of new synthetically prepared fluoroquinolone derivative 6-fluoro-8-nitro-4-oxo-1,4-dihydroquinoline-3-carboxylate (6FN) in vitro. The cytotoxicity/toxicity studies (concentrations in the range 1-100μM) are focused on the cervical cancer cells HeLa, murine melanoma cancer cells B16, non-cancer fibroblast NIH-3T3 cells and reconstructed human epidermis tissues EpiDerm™. The significant growth inhibition of cancer cells HeLa and B16 was detected. The cytotoxicity was mediated via apoptosis-associated with activation of caspase-9 and -3. After 72h of treatment, the two highest 6FN concentrations (100 and 50μM) induced toxic effect on epidermis tissue EpiDerm™, even the structural changes in tissue were observed with concentration of 100μM. The effective induction of RAW 264.7 macrophages cell-release of pro- and anti-inflammatory T_H1, T_H2 and T_H17 cytokines, with anti-cancer and/or anti-infection activities, respectively, has been revealed even following low-dose exposition.

Correlation among the toxicity profiling (28-days repeated oral dose toxicity), toxicokinetics and tissue distribution data of ulifloxacin, the active metabolite of prulifloxacin in Wistar albino rats

This experiment was designed to investigate correlation among 28-days repeated oral dose toxicity, toxicokinetics and tissue distribution data of ulifloxacin (active metabolite of prulifloxacin) in Wistar albino rats. Prulifloxacin was administered for 28-days in rats at 0, 100, 200, 400mg/kg/day followed by 14-days recovery period. Simultaneously different toxicokinetic parameters and tissue distributions of ulifloxacin was examined by LC-MS/MS method. Plasma levels and tissue concentrations of ulifloxacin were increased with dose-related manner. Ulifloxacin was also distributed to many tissues, and concentration in lungs nearly equivalent to the plasma concentration. Based on these results it was concluded that long-term repeated dose of prulifloxacin may produce different blood parameters abnormality, liver damage, stomach ulcer, joint damage and dysfunction of lungs in rats which relates to high tissue distribution and accumulation of ulifloxacin in these tissues. These findings help in management of prulifloxacin induced adverse effects by appropriate dose selection in clinical practice.

Short-course fluoroquinolones in acute exacerbations of chronic bronchitis

It is estimated that 50-70% of acute exacerbations of chronic bronchitis (AECB) are caused by bacterial infections. Appropriate selection of antimicrobials may lead to better outcomes and reduced healthcare costs. Respiratory fluoroquinolones (moxifloxacin, levofloxacin and gemifloxacin) have a broad spectrum of activity against most AECB-causing pathogens and are used as first-line treatment in patients with comorbidity, severe airway obstruction or recurrent exacerbations. We review studies, identified through a MEDLINE search, that compared clinical efficacy and speed of recovery for short-course (≤ 5 days) fluoroquinolone therapy with commonly prescribed standard therapy (≥ 7 days). Among 177 studies reporting the use of fluoroquinolones for AECB treatment, 23 used a short-course regimen, shown to be at least as effective as standard therapy of 7 or more days duration. Furthermore, evidence suggests that short-course therapy offers faster resolution of symptoms, faster rate of recovery, fewer relapses, fewer and shorter hospitalizations, and longer time between recurrences.

Twenty-eight days repeated oral dose toxicity study of gemifloxacin in Wistar albino rats

The purpose of this study was to investigate the potential toxicity of gemifloxacin by 28-day repeated oral dose in Wistar albino rats. The test article, was administered daily by gavage to male and female rats at dose levels of 0, 50, 100, 200 mg/kg/day. At the end of treatment period, 12 rats/sex/group was sacrificed, while six extra rats/sex in the vehicle control and highest dose groups sacrificed after 14 days recovery period. During the treatment and recovery periods, clinical signs, mortality, body weights, food and water consumption, ophthalmoscopy, urinalysis, phototoxicity, hematology, serum biochemistry, synovial fluid biochemistry, electrocardiogram (ECG), gross findings, organ weights, microscopic examination of synovial fluid, and histopathology were examined. Hematological and serum biochemical investigations revealed a dose-dependent increase in the total white blood cell (WBC), total bilirubin (T-BIL), glucose (GLU), alanine aminotransferase (ALT) and significant decreases in total protein (TP) were observed in both sexes at the same dose, at the end of treatment period, but the levels returned toward normal during the recovery period. Histopathology of talar joint showed that erosion of the articular surface of that joint in both sexes at the end of treatment period at the dose level of 200 mg/kg/day. Degenerative changes in tendinocytes were observed in Achilles tendon of both sexes at the high dose level at the end of treatment period. In histopathological study shows partial effacement of liver architecture and focal ulceration in gastric mucosa at the high dose level at the end of treatment period. Based on these results, it was concluded that 28 days repeated oral dose of gemifloxacin caused increases in the liver weight, WBC count, T-BIL, glucose level, ALT, decreasing the TP, cause chronic hepatitis and acute gastritis, erosion of the articular surface of joint and histopathologic changes in Achilles tendon in rats at the dose level of 200 mg/kg/day.

Tratamiento farmacológico de las agudizaciones infecciosas de la EPOC

Las agudizaciones de la enfermedad pulmonar obstructiva crónica (EPOC) son episodios frecuentes y potencialmente graves, que dejan un impacto permanente en la calidad de vida y en la función pulmonar de los pacientes. Hasta un 75% de las agudizaciones tiene una etiología bacteriana, en ocasiones asociada a infección vírica. La tasa de fracaso del tratamiento ambulatorio de las agudizaciones alcanza el 20-25% y la gravedad de la enfermedad de base es el principal factor de riesgo de fracaso. La colonización bacteriana persistente es un factor de riesgo de agudizaciones frecuentes y graves, y de más rápida progresión de la EPOC. Por este motivo el tratamiento antibiótico de las agudizaciones debe perseguir no sólo la curación clínica, sino también la mejor erradicación posible para acelerar la recuperación y prevenir las recaídas. Nuevos ensayos clínicos han demostrado que el antibiótico que consigue una mejor erradicación puede prolongar el tiempo sin síntomas de agudización.