The development of pharmacokinetically enhanced amoxicillin/clavulanate for the management of respiratory tract infections in adults

Effect of an antimicrobial drug on lung microbiota in healthy dogs

Alterations of the lung microbiota (LM) are associated with clinical features in chronic lung diseases (CLDs) with growing evidence that an altered LM contributes to the pathogenesis of such disorders. The common use of antimicrobial drugs in the management of CLDs likely represents a confounding factor in the study of the LM. The aim of the present study was to assess the effect of oral administration of amoxicillin/clavulanic acid (AC) on the LM in healthy dogs (n = 6) at short (immediately after stopping AC [D10]) and medium-term (16 days after stopping AC [D26]). Metagenetic analyses were performed on the V1–V3 hypervariable region of 16S rDNA after extraction of total bacterial DNA from samples of bronchoalveolar lavage fluid (BALF). AC did not induce significant changes in BALF cellular counts or in the bacterial load or microbial richness, evenness and α-diversity, while the β-diversity was clearly modified at D10 compared with D0 (before AC administration) and D26 (P < 0.01). The relative abundance of Bacteroidetes and Proteobacteria increased at D10 (P < 0.01) in comparison with D0 and D26 (P < 0.01). The relative abundance of Firmicutes decreased from D0 to D10 (P < 0.01) and increased from D10 to D26 (P < 0.01), but was still lower than at D0 (P < 0.01). The proportion of Actinobacteria increased at D26 compared with D0 and D10 (P < 0.01). Significant differences between timepoints at the level of family, genus or species were not found. In conclusion, in healthy dogs, oral administration of AC induces significant changes in LM at the phyla level and in the β-diversity. Most changes normalize within 2 weeks after discontinuation of AC.

Susceptibilities of MDR Mycobacterium tuberculosis isolates to unconventional drugs compared with their reported pharmacokinetic/pharmacodynamic parameters

Background

The second-line drugs recommended to treat drug-resistant TB are toxic, expensive and difficult to procure. Given increasing resistance, the need for additional anti-TB drugs has become more urgent. But new drugs take time to develop and are expensive. Some commercially available drugs have reported anti-mycobacterial activity but are not routinely used because supporting laboratory and clinical evidence is sparse.

Methods

We analysed 217 MDR M. tuberculosis isolates including 153 initial isolates from unique patients and 64 isolates from follow-up specimens during the course of treatment. The resazurin microdilution assay was performed to determine MICs of trimethoprim/sulfamethoxazole, mefloquine, thioridazine, clofazimine, amoxicillin/clavulanate, meropenem/clavulanate, nitazoxanide, linezolid and oxyphenbutazone. Isoniazid was used for validation. We calculated the MIC 50 and MIC 90 as the MICs at which growth of 50% and 90% of isolates was inhibited, respectively.

Results

The MIC 50 s, in mg/L, for initial isolates were as follows: trimethoprim/sulfamethoxazole, 0.2/4; mefloquine, 8; thioridazine, 4; clofazimine, 0.25; amoxicillin/clavulanate, 16/8; meropenem/clavulanate, 1/2.5; nitazoxanide, 16; linezolid, 0.25; and oxyphenbutazone, 40. The MIC 90 s, in mg/L, for initial isolates were as follows: trimethoprim/sulfamethoxazole, 0.4/8; mefloquine, 8; thioridazine, 8; clofazimine, 0.5; amoxicillin/clavulanate, 32/16; meropenem/clavulanate, 8/2.5; nitazoxanide, 16; linezolid, 0.25; and oxyphenbutazone, 60. By comparison, the MIC 90 of isoniazid was >4 mg/L, as expected. There was no evidence that previous treatment affected susceptibility to any drug.

Conclusions

Most drugs demonstrated efficacy against M. tuberculosis . When these MICs are compared with the published pharmacokinetic/pharmacodynamic profiles of the respective drugs in humans, trimethoprim/sulfamethoxazole, meropenem/clavulanate, linezolid, clofazimine and nitazoxanide appear promising and warrant further clinical investigation.

Formulation, characterization and physicochemical evaluation of amoxicillin effervescent tablets

BACKGROUND

Amoxicillin is a semisynthetic antibiotic, which is used as an antimicrobial drug. This study was designed to formulate amoxicillin effervescent tablets, aimed at improved patient compliance and increased drug stability.

MATERIALS AND METHODS

In this study, nine effervescent tablet formulations were prepared from amoxicillin trihydrate. The effervescent base was comprised of various amounts of citric acid and sodium bicarbonate. Powders and granules were evaluated for their particle size, bulk density, tapped density, compressibility index, Hausner's ratio and angle of repose. The effervescent tablets were then prepared from powders and granules of acceptable quality by direct compression and fusion methods. The tablets were evaluated for weight variation, friability, pH of solution, carbon dioxide (CO2) content, hardness, effervescence time, thickness, assay, content uniformity, water content and equilibrium moisture content.

RESULTS

The results indicated better flowability of granules prepared by fusion method as compared with the direct compression. The percent weight variations of tablets were within the acceptable limit of 0.5%. The friability was less than 1% in all formulations. The solution pH of tablets prepared by direct compression and fusion methods ranged from 4.55 to 5.74 and 4.74-5.84, respectively. The CO2 amounts generated by of fusion method tablets were smaller as compared to the direct compression method. The hardness of tablets was 40.66-56 for direct compression method and 60.6-74.6 for fusion method. The tablets produced by the fusion method had a larger thickness and lower water content than tablets produced by direct compression method.

CONCLUSION

Tablets prepared by the fusion method exhibited superior pre- and post-compression characteristics as compared to tablets prepared by direct compression method.

Current treatment of community-acquired pneumonia

INTRODUCTION

Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality worldwide. Management decisions regarding site of care, extent of assessment and level of treatment are based primarily on disease severity (outpatient, inpatient and ICU admission). Despite the developments in antibiotic therapy, CAP is still the most common infectious cause of death.

AREAS COVERED

There are several challenges with the management of CAP, from the accurate diagnosis, decisions about place of therapy and the choice of appropriate antibiotics. An extensive literature review of manuscripts, in PubMed, published in the past 10 years has been performed, using combinations of words and terms appropriate to the concepts of CAP, treatment, guidelines and corticoids. Some empirical antimicrobial regimens, such as macrolides, are still being debated; some new antibiotics and adjunctive therapies (corticoids) have recently been tested. This is a review of current recommended antimicrobials regimens, novel approaches and adjunctive drugs for the treatment of CAP.

EXPERT OPINION

Effective management of CAP requires risk stratification of patients by severity and proper place of therapy. Additional therapeutic interventions along with antibiotics may help to improve outcome in patients with CAP, especially in severe CAP.

Guidelines for the management of adult lower respiratory tract infections--summary

This document is an update of Guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice in the management of adult patients with LRTI. Topics include management outside hospital, management inside hospital (including community-acquired pneumonia (CAP), acute exacerbations of COPD (AECOPD), acute exacerbations of bronchiectasis) and prevention. The target audience for the Guideline is thus all those whose routine practice includes the management of adult LRTI.

Guidelines for the management of adult lower respiratory tract infections--full version

This document is an update of Guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice in the management of adult patients with LRTI. Topics include management outside hospital, management inside hospital (including community-acquired pneumonia (CAP), acute exacerbations of COPD (AECOPD), acute exacerbations of bronchiectasis) and prevention. Background sections and graded evidence tables are also included. The target audience for the Guideline is thus all those whose routine practice includes the management of adult LRTI.

Community acquired bacterial pneumonia

IMPORTANCE OF THE FIELD

Community-acquired pneumonia (CAP) is a common and potentially life-threatening illness that continues to be a major medical problem. Among infectious diseases, CAP is the leading cause of death in the world and is associated with a substantial economic burden to health are systems around the globe.

AREAS COVERED IN THIS REVIEW

Recently identified clinical and biochemical tools promise to improve the assessment of CAP severity. Various prognostic scoring systems and predictive biomarkers have been proposed as tools to aid clinicians in key management decisions. This review provides a summary of current evidence about the use of prognostic scoring systems and biomarkers in the management of patients presenting with CAP. According to the existing guidelines, until more accurate and rapid diagnostic methods are available, the initial treatment for most patients with CAP will remain empirical. Some novel antibiotic and nonantibiotic therapies have recently been tested; some empirical antimicrobial regimens are still being debated. This review summarizes the recent advances in the field of therapy and novel approaches. We searched PubMed for English-language references published from 1997 to 2009 using combinations of the following terms: 'community acquired pneumonia', 'community acquired bacterial pneumonia', 'therapy', 'antibiotics', 'antimicrobials', 'prognostic scoring systems', 'biomarkers', 'diagnostic testing', 'guidelines' 'etiological diagnosis'.

WHAT THE READER WILL GAIN

A thorough description about recent advances in the field of therapy and novel approaches of CAP, as well as a summary of current evidence about the use of prognostic scoring systems and biomarkers in the management of patients presenting with CAP, is presented.

TAKE HOME MESSAGE

Recent developments have made significant contributions to the management of CAP patients. However, various hot topics remain open and urgently require prospective studies in order to optimize the outcomes of CAP.