Acute exacerbation of chronic bronchitis: expanding short-course therapy

Levofloxacin for the treatment of respiratory tract infections

INTRODUCTION

Fluoroquinolone use has dramatically increased since the introduction of the first respiratory fluoroquinolone in the late 1990s. Levofloxacin , like other fluoquinolones, is a potent antibiotic, due to high levels of susceptibility among Gram-negative, Gram-positive (including penicillin-resistant strains of Streptococcus pneumonia) and atypical pathogens. Levofloxacin is recommended for the treatment of community-acquired pneumonia (CAP), hospital-acquired pneumonia (HAP) and in the management of acute exacerbations of chronic bronchitis (AECB). Levofloxacin demonstrates good safety, bioavailability and tissue penetration, thus maintaining adequate concentrations at the site of infection. High-dose (750 mg), short-course (5 days) therapy regimens may offer improved treatment, especially in HAP, due to higher drug concentrations, increased adherence and the potential to reduce the development of resistance.

AREAS COVERED

This article covers medical literature published in any language since 1990 until November 2011, on 'levofloxacin', identified using PubMed and MEDLINE. The search terms used were 'levofloxacin' and 'community acquired pneumonia', 'hospital pneumonia' or 'AECB'.

EXPERT OPINION

Levofloxacin is a valuable antimicrobial agent and an optimal treatment option for AECB, CAP (as a monotherapy) and HAP (as combination therapy at a high-dose regimen). Its improved bioavailability and safety profile makes the possibility of shorter hospital stays a reality.

Formulation design and pharmaceutical development of a novel controlled release form of azithromycin for single-dose therapy

BACKGROUND

Azithromycin's long serum half-life (approximately 68 hours) allows for a short 5-day, 3-day, and now 1-day course therapy with a large 2-g dose. Although the single-dose, 1-day therapy offers the advantage of 100% patient compliance, tolerance of such large dose becomes an issue.

METHODS

The dosage form discussed in this article employed a melt-congealing process to produce matrix microspheres with a 3-hour, first-order release. The vehicle blend included alkalizing agents to minimize GI side effects, minimize loss of bioavailability, and mask the bitter taste of azithromycin.

RESULTS

Azithromycin microspheres are small (approximately 200 microm) with a narrow particle size distribution. Drug release was optimized by controlling the amount of dissolution enhancer in the microspheres and by the addition of proper amount of alkalizing agents in the vehicle blend. The final formulation was selected based on a balance between bioavailability and tolerability.

CONCLUSIONS

Drug release from the microspheres was shown to occur via diffusion through the larger pores formed by dissolution of azithromycin crystals and the smaller interconnected pores formed by dissolution of poloxamer. Several clinical studies have been conducted with the formulation to evaluate its pharmacokinetics and to demonstrate its safety and efficacy. The combined suspension formulation for a 2-g dose of azithromycin provided taste-masking and good tolerability.

Treatment of acute bacterial exacerbations of chronic bronchitis

BACKGROUND

Controversies persist regarding the optimal management of patients with acute exacerbations of chronic bronchitis (AECB).

OBJECTIVE

To evaluate the available evidence on relevant issues, namely the need for administering antimicrobials in patients with AECB, the identification of the subgroup of patients with AECB needing antibiotics, the antimicrobial regimen of choice and its optimal duration, the existence of new agents, and the value of non-antimicrobial regimens for AECB.

METHODS

Data from various sources of evidence, including recent relevant meta-analyses, were appraised.

CONCLUSION

Administration of antimicrobial agents, combined with bronchodilators and systemic corticosteroids, is warranted in approximately half of AECBs (i.e., in bacterial exacerbations) to achieve a survival benefit. Simple clinical parameters, mainly sputum purulence, and biomarkers, such as procalcitonin, are useful in identifying patients requiring antibiotics. Advanced antibiotics (quinolones, macrolides, or amoxicillin/clavulanic acid) are more effective than 'old' antibiotics in AECB; regimens of short duration (for 5 days) are preferred. There is no difference between several classes of advanced antibiotics regarding their short-term effectiveness; however, quinolones are associated with better long-term outcomes than macrolides. Newer quinolones and new formulations of macrolides enrich clinicians' armamentarium against AECB.

Moxifloxacin: a respiratory fluoroquinolone

BACKGROUND

Respiratory quinolones are a class of antimicrobials with a high activity against most respiratory pathogens. Moxifloxacin is a fourth-generation fluoroquinolone that has been shown to be effective against Gram-positive, Gram-negative, and atypical strains, as well as multi-drug resistant Streptococcus pneumoniae.

OBJECTIVE

To review and update the clinical efficacy of moxifloxacin in the treatment of respiratory infections.

METHOD

To perform a systematic review of publications on the clinical efficacy of moxifloxacin in respiratory infections.

RESULTS

The clinical efficacy of moxifloxacin has been shown in controlled studies of community-acquired pneumonia, exacerbations of chronic bronchitis and acute bacterial rhinosinusitis. Moxifloxacin has demonstrated a faster resolution of symptoms in community-acquired pneumonia and exacerbations of chronic bronchitis patients compared with first-line therapy together with excellent eradication rates.

CONCLUSIONS

The use of moxifloxacin as first-line therapy for moderate to severe respiratory infections in the community and the hospital has been recognized in international guidelines.

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.