Randomized, double-blind, multicenter comparison of oral cefditoren 200 or 400 mg BID with either cefuroxime 250 mg BID or cefadroxil 500 mg BID for the treatment of uncomplicated skin and skin-structure infections

In vivo Pharmacokinetics/Pharmacodynamics Profiles for Appropriate Doses of Cefditoren pivoxil against S. pneumoniae in Murine Lung-Infection Model

PURPOSE

Cefditoren, the active form of cefditoren pivoxil, is an oral cephalosporin antimicrobial drug. Although cefditoren exhibits high antimicrobial activity against Streptococcus pneumoniae, its pharmacokinetics/pharmacodynamics (PK/PD) characteristics remain unknown. This study aimed to determine its PK/PD parameter with target values for cefditoren against S. pneumoniae in S. pneumoniae lung-infected mice and to simulate MIC range of S. pneumoniae that can be expected to be treated at approved cefditoren doses in human using population pharmacokinetic (PPK) data from patients.

METHODS

Susceptibility testing and time-kill assays against S. pneumoniae ATCC® 49619 were performed for in vitro PD evaluation. Based on the results of a PK study in healthy mice and PD studies in S. pneumoniae lung-infected mice, optimal PK/PD parameters were determined using the correlation curve between the PK/PD parameters and lung bacterial count changes. The target value was calculated to achieve a 2 log10 reduction in the lung bacterial counts.

RESULTS

In vitro PD evaluation showed that cefditoren had a potent antimicrobial effect against S. pneumoniae in a time-dependent manner at concentrations above the MIC. In PK/PD analyses, both fAUC24/MIC and fCmax/MIC were well correlated with bactericidal efficacy, achieving 2 log10-kill with fAUC24/MIC ≥ 63 and fCmax/MIC ≥ 16.

CONCLUSIONS

Cefditoren pivoxil has good therapeutic efficacy against acute pneumonia caused by S. pneumoniae with a MIC ≤ 0.031-0.063 mg/L at approved doses in adults and children.

The impact of antibiotics on clinical response over time in uncomplicated cellulitis: a systematic review and meta-analysis

PURPOSE

Antibiotic treatment of uncomplicated cellulitis is highly variable with respect to agent, dose, and route of administration. As there is uncertainty about optimal/appropriate time to reassess, we aimed to assess time to clinical response.

METHODS

We conducted a systematic review of randomized controlled trials reporting clinical response of uncomplicated cellulitis to antibiotic treatment over multiple timepoints. PubMed, Embase, CENTRAL, WHO ICTRP, and clinicaltrials.gov were searched from inception to June 2021 without language restrictions. The primary outcome was time to clinical response. Other outcomes were components of clinical response (pain, severity score, redness, edema measured at ≥ 2 timepoints) and the proportion of patients with treatment failure. We performed a pooled estimate of the average time to clinical response together with 95% confidence intervals using a random effects model.

RESULTS

We included 32 randomized controlled trials (n = 13,576 participants). The mean time to clinical response was 1.68 days (95%CI 1.48-1.88; I² = 76%). The response to treatment for specific components was as follows: ~ 50% reduction of pain and severity score by day 5, a ~ 33% reduction in area of redness by day 2-3, and a 30-50% reduction of proportion of patients with edema by day 2-4. Treatment failure was variably defined with an overall failure rate of 12% (95%CI 9-16%).

CONCLUSION

The best available data suggest the optimal time to clinical reassessment is between 2 and 4 days, but this must be interpreted with caution due to considerable heterogeneity and small number of included studies.

Assessment of Antibiotic Treatment of Cellulitis and Erysipelas: A Systematic Review and Meta-analysis

Importance

The optimum antibiotic treatment for cellulitis and erysipelas lacks consensus. The available trial data do not demonstrate the superiority of any agent, and data are limited on the most appropriate route of administration or duration of therapy.

Objective

To assess the efficacy and safety of antibiotic therapy for non-surgically acquired cellulitis.

Data Sources

The following databases were searched to June 28, 2016: Cochrane Central Register of Controlled Trials (2016, issue 5), Medline (from 1946), Embase (from 1974), and Latin American and Caribbean Health Sciences Information System (LILACS) (from 1982). In addition, 5 trials databases and the reference lists of included studies were searched. Further searches of PubMed and Google Scholar were undertaken from June 28, 2016, to December 31, 2018.

Study Selection

Randomized clinical trials comparing different antibiotics, routes of administration, and treatment durations were included.

Data Extraction and Synthesis

For data collection and analysis, the standard methodological procedures of the Cochrane Collaboration were used. For dichotomous outcomes, the risk ratio and its 95% CI were calculated. A summary of findings table was created for the primary end points, adopting the GRADE approach to assess the quality of the evidence.

Main Outcomes and Measures

The primary outcome was the proportion of patients cured, improved, recovered, or symptom-free or symptom-reduced at the end of treatment, as reported by the trial. The secondary outcome was any adverse event.

Results

A total of 43 studies with a total of 5999 evaluable participants, whose age ranged from 1 month to 96 years, were included. Cellulitis was the primary diagnosis in only 15 studies (35%), and in other studies the median (interquartile range) proportion of patients with cellulitis was 29.7% (22.9%-50.3%). Overall, no evidence was found to support the superiority of any 1 antibiotic over another, and antibiotics with activity against methicillin-resistant Staphylococcus aureus did not add an advantage. Use of intravenous antibiotics over oral antibiotics and treatment duration of longer than 5 days were not supported by evidence.

Conclusions and Relevance

In this systematic review and meta-analysis, only low-quality evidence was found for the most appropriate agent, route of administration, and duration of treatment for patients with cellulitis; future trials need to use a standardized set of outcomes, including severity scoring, dosing, and duration of therapy.

Antibiotics for uncomplicated skin abscesses: systematic review and network meta-analysis

OBJECTIVE

To assess the impact of adjunctive antibiotic therapy on uncomplicated skin abscesses.

DESIGN

Systematic review and network meta-analysis.

DATA SOURCES

Medline, Embase, the Cochrane Central Register of Controlled Trials and ClinicalTrials.gov.

STUDY SELECTION

A BMJ Rapid Recommendation panel provided input on design, important outcomes and the interpretation of the results. Eligible randomised controlled trials (RCTs) included a comparison of antibiotics against no antibiotics or a comparison of different antibiotics in patients with uncomplicated skin abscesses, and reported outcomes prespecified by the linked guideline panel.

REVIEW METHODS

Reviewers independently screened abstracts and full texts for eligibility, assessed risk of bias and extracted data. We performed random-effects meta-analyses that compared antibiotics with no antibiotics, along with a limited number of prespecified subgroup hypotheses. We also performed network meta-analysis with a Bayesian framework to compare effects of different antibiotics. Quality of evidence was assessed with The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

Fourteen RCTs including 4198 patients proved eligible. Compared with no antibiotics, antibiotics probably lower the risk of treatment failure (OR 0.58, 95% CI 0.37 to 0.90; low quality), recurrence within 1 month (OR 0.48, 95% CI 0.30 to 0.77; moderate quality), hospitalisation (OR 0.55, 95% CI 0.32 to 0.94; moderate quality) and late recurrence (OR 0.64, 95% CI 0.48 to 0.85; moderate quality). However, relative to no use, antibiotics probably increase the risk of gastrointestinal side effects (trimethoprim and sulfamethoxazole (TMP-SMX): OR 1.28, 95% CI 1.04 to 1.58; moderate quality; clindamycin: OR 2.29, 95% CI 1.35 to 3.88; high quality) and diarrhoea (clindamycin: OR 2.71, 95% CI 1.50 to 4.89; high quality). Cephalosporins did not reduce the risk of treatment failure compared with placebo (moderate quality).

CONCLUSIONS

In patients with uncomplicated skin abscesses, moderate-to-high quality evidence suggests TMP-SMX or clindamycin confer a modest benefit for several important outcomes, but this is offset by a similar risk of adverse effects. Clindamycin has a substantially higher risk of diarrhoea than TMP-SMX. Cephalosporins are probably not effective.

The Penicillin for the Emergency Department Outpatient treatment of CELLulitis (PEDOCELL) trial: update to the study protocol and detailed statistical analysis plan (SAP)

Background

Cellulitis is a painful, potentially serious, infectious process of the dermal and subdermal tissues and represents a significant disease burden. The statistical analysis plan (SAP) for the Penicillin for the Emergency Department Outpatient treatment of CELLulitis (PEDOCELL) trial is described here. The PEDOCELL trial is a multicentre, randomised, parallel-arm, double-blinded, non-inferiority clinical trial comparing the efficacy of flucloxacillin (monotherapy) with combination flucloxacillin/phenoxymethylpenicillin (dual therapy) for the outpatient treatment of cellulitis in the emergency department (ED) setting. To prevent outcome reporting bias, selective reporting and data-driven results, the a priori-defined, detailed SAP is presented here.

Methods/design

Patients will be randomised to either orally administered flucloxacillin 500 mg four times daily and placebo or orally administered 500 mg of flucloxacillin four times daily and phenoxymethylpenicillin 500 mg four times daily. The trial consists of a 7-day intervention period and a 2-week follow-up period. Study measurements will be taken at four specific time points: at patient enrolment, day 2–3 after enrolment and commencing treatment (early clinical response (ECR) visit), day 8–10 after enrolment (end-of-treatment (EOT) visit) and day 14–21 after enrolment (test-of-cure (TOC) visit). The primary outcome measure is investigator-determined clinical response measured at the TOC visit. The secondary outcomes are as follows: lesion size at ECR, clinical treatment failure at each follow-up visit, adherence and persistence of trial patients with orally administered antibiotic therapy at EOT, health-related quality of life (HRQoL) and pharmacoeconomic assessments. The plan for the presentation and comparison of baseline characteristics and outcomes is described in this paper.

Discussion

This trial aims to establish the non-inferiority of orally administered flucloxacillin monotherapy with orally administered flucloxacillin/phenoxymethylpenicillin dual therapy for the ED-directed outpatient treatment of cellulitis. In doing so, this trial will bridge a knowledge gap in this understudied and common condition and will be relevant to clinicians across several different disciplines. The SAP for the PEDOCELL trial was developed a priori in order to minimise analysis bias.

Trial registration

EU Clinical Trials Register (EudraCT number: 2016-001528-69). Registered on 5 April 2016.

ClinicalTrials.gov, ID: NCT02922686. Registered on 9 August 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2121-2) contains supplementary material, which is available to authorized users.

Failure of antibiotics in cellulitis trials: a systematic review and meta-analysis

OBJECTIVES

The objectives of the study are to quantify trial-to-trial variability in antibiotic failure rates, in randomized clinical trials of cellulitis treatment and to provide a point estimate for the treatment failure rate across trials.

METHODS

We conducted a structured search for clinical trials evaluating antibiotic treatment of cellulitis, indexed in PubMed by August 2015. We included studies published in English and excluded studies conducted wholly outside of developed countries because the pathophysiology of cellulitis is likely to be different in such settings. Two authors reviewed all abstracts identified for possible inclusion. Of studies identified initially, 5% met the selection criteria. Two reviewers extracted data independently, and data were pooled using the Freeman-Tukey transformation under a random-effects model. Our primary outcome was the summary estimate of treatment failure across intent-to-treat and clinically evaluable participants.

RESULTS

We included 19 articles reporting data from 20 studies, for a total of 3935 patients. Treatment failure was reported in 6% to 37% of participants in the 9 trials reporting intent-to-treat results, with a summary point estimate of 18% failing treatment (95% confidence interval, 15%-21%). In the 15 articles evaluating clinically evaluable participants, treatment failure rates ranged from 3% to 42%, and overall, 12% (95% confidence interval, 10%-14%) were designated treatment failures.

CONCLUSIONS

Treatment failure rates vary widely across cellulitis trials, from 6% to 37%. This may be due to confusion of cellulitis with its mimics and perhaps problems with construct validity of the diagnosis of cellulitis. Such factors bias trials toward equivalence and, in routine clinical care, impair quality and antibiotic stewardship. Objective diagnostic tools are needed.

Staphylococcus aureus infections: epidemiology, pathophysiology, clinical manifestations, and management

Staphylococcus aureus is a major human pathogen that causes a wide range of clinical infections. It is a leading cause of bacteremia and infective endocarditis as well as osteoarticular, skin and soft tissue, pleuropulmonary, and device-related infections. This review comprehensively covers the epidemiology, pathophysiology, clinical manifestations, and management of each of these clinical entities. The past 2 decades have witnessed two clear shifts in the epidemiology of S. aureus infections: first, a growing number of health care-associated infections, particularly seen in infective endocarditis and prosthetic device infections, and second, an epidemic of community-associated skin and soft tissue infections driven by strains with certain virulence factors and resistance to β-lactam antibiotics. In reviewing the literature to support management strategies for these clinical manifestations, we also highlight the paucity of high-quality evidence for many key clinical questions.

A Comparison of Cefditoren Pivoxil 8-12 mg/kg/day and Cefditoren Pivoxil 16-20 mg/kg/day in Treatment of Children With Acute Presumed Bacterial Rhinosinusitis: A Prospective, Randomized, Investigator-Blinded, Parallel-Group Study

OBJECTIVES

Cefditoren pivoxil (CDT) has been used in the treatment of rhinosinusitis. However, little is known about the efficacy of this drug at low and high doses. This study was to compare the efficacy and safety of low dose (8-12 mg/kg/day) and high dose (16-20 mg/kg/day) CDT in the treatment of children with uncomplicated acute rhinosinusitis (ARS).

METHODS

This investigation was a randomized, investigator-blinded, and parallel study, conducted in patients (aged 1-15 years) with a clinical diagnosis of uncomplicated ARS. Two groups of patients randomly received low dose or high dose CDT for 14 days. Patients' symptoms were assessed quantitatively using a quantitative symptom score (the S5 score). The changes in sinus symptoms and adverse events were provided by patients and their parents/caregivers. The response rate and adverse effects were evaluated at days 7 and 14. The relapse rate was recorded at days 21 and 28. The recurrences of sinus symptoms at day 60 were also assessed.

RESULTS

One hundred forty patients were recruited and randomized; 72 received low dose CDT (group I) and 68 received high dose CDT (group II). There were no significant differences in demographic data including sex, age, presenting symptoms, medical history, and X-ray findings between two groups. The responses rate at day 14 in groups I and II were 95.5% and 95.4%, respectively (P>0.99). There were no significant differences between groups in relapse rate at day 28 and no recurrence at day 60 in either group. The most common treatment-related adverse events were diarrhea (4.2% in group I vs. 2.9% in group II) and vomiting (2.8% in group I vs. 10.3% in group II). There was no statistically significant difference in adverse events between groups.

CONCLUSION

Both low and high doses regimens of CDT appeared a similar clinical outcome for treatment in uncomplicated ARS in pediatric patients.

Antibiotic therapy for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) in non surgical wounds

BACKGROUND

Non surgical wounds include chronic ulcers (pressure or decubitus ulcers, venous ulcers, diabetic ulcers, ischaemic ulcers), burns and traumatic wounds. The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) colonisation (i.e. presence of MRSA in the absence of clinical features of infection such as redness or pus discharge) or infection in chronic ulcers varies between 7% and 30%. MRSA colonisation or infection of non surgical wounds can result in MRSA bacteraemia (infection of the blood) which is associated with a 30-day mortality of about 28% to 38% and a one-year mortality of about 55%. People with non surgical wounds colonised or infected with MRSA may be reservoirs of MRSA, so it is important to treat them, however, we do not know the optimal antibiotic regimen to use in these cases.

OBJECTIVES

To compare the benefits (such as decreased mortality and improved quality of life) and harms (such as adverse events related to antibiotic use) of all antibiotic treatments in people with non surgical wounds with established colonisation or infection caused by MRSA.

SEARCH METHODS

We searched the following databases: The Cochrane Wounds Group Specialised Register (searched 13 March 2013); The Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 2); Database of Abstracts of Reviews of Effects (2013, Issue 2); NHS Economic Evaluation Database (2013, Issue 2); Ovid MEDLINE (1946 to February Week 4 2013); Ovid MEDLINE (In-Process & Other Non-Indexed Citations, March 12, 2013); Ovid EMBASE (1974 to 2013 Week 10); EBSCO CINAHL (1982 to 8 March 2013).

SELECTION CRITERIA

We included only randomised controlled trials (RCTs) comparing antibiotic treatment with no antibiotic treatment or with another antibiotic regimen for the treatment of MRSA-infected non surgical wounds. We included all relevant RCTs in the analysis, irrespective of language, publication status, publication year, or sample size.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified the trials, and extracted data from the trial reports. We calculated the risk ratio (RR) with 95% confidence intervals (CI) for comparing the binary outcomes between the groups and planned to calculate the mean difference (MD) with 95% CI for comparing the continuous outcomes. We planned to perform the meta-analysis using both fixed-effect and random-effects models. We performed intention-to-treat analysis whenever possible.

MAIN RESULTS

We identified three trials that met the inclusion criteria for this review. In these, a total of 47 people with MRSA-positive diabetic foot infections were randomised to six different antibiotic regimens. While these trials included 925 people with multiple pathogens, they reported the information on outcomes for people with MRSA infections separately (MRSA prevalence: 5.1%). The only outcome reported for people with MRSA infection in these trials was the eradication of MRSA. The three trials did not report the review's primary outcomes (death and quality of life) and secondary outcomes (length of hospital stay, use of healthcare resources and time to complete wound healing). Two trials reported serious adverse events in people with infection due to any type of bacteria (i.e. not just MRSA infections), so the proportion of patients with serious adverse events was not available for MRSA-infected wounds. Overall, MRSA was eradicated in 31/47 (66%) of the people included in the three trials, but there were no significant differences in the proportion of people in whom MRSA was eradicated in any of the comparisons, as shown below.1. Daptomycin compared with vancomycin or semisynthetic penicillin: RR of MRSA eradication 1.13; 95% CI 0.56 to 2.25 (14 people).2. Ertapenem compared with piperacillin/tazobactam: RR of MRSA eradication 0.71; 95% CI 0.06 to 9.10 (10 people).3. Moxifloxacin compared with piperacillin/tazobactam followed by amoxycillin/clavulanate: RR of MRSA eradication 0.87; 95% CI 0.56 to 1.36 (23 people).

AUTHORS' CONCLUSIONS

We found no trials comparing the use of antibiotics with no antibiotic for treating MRSA-colonised non-surgical wounds and therefore can draw no conclusions for this population. In the trials that compared different antibiotics for treating MRSA-infected non surgical wounds, there was no evidence that any one antibiotic was better than the others. Further well-designed RCTs are necessary.

Interventions for impetigo

BACKGROUND

Impetigo is a common, superficial bacterial skin infection, which is most frequently encountered in children. There is no generally agreed standard therapy, and guidelines for treatment differ widely. Treatment options include many different oral and topical antibiotics as well as disinfectants. This is an updated version of the original review published in 2003.

OBJECTIVES

To assess the effects of treatments for impetigo, including non-pharmacological interventions and 'waiting for natural resolution'.

SEARCH METHODS

We updated our searches of the following databases to July 2010: the Cochrane Skin Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 2005), EMBASE (from 2007), and LILACS (from 1982). We also searched online trials registries for ongoing trials, and we handsearched the reference lists of new studies found in the updated search.

SELECTION CRITERIA

Randomised controlled trials of treatments for non-bullous, bullous, primary, and secondary impetigo.

DATA COLLECTION AND ANALYSIS

Two independent authors undertook all steps in data collection. We performed quality assessments and data collection in two separate stages.

MAIN RESULTS

We included 57 trials in the first version of this review. For this update 1 of those trials was excluded and 12 new trials were added. The total number of included trials was, thus, 68, with 5578 participants, reporting on 50 different treatments, including placebo. Most trials were in primary impetigo or did not specify this.For many of the items that were assessed for risk of bias, most studies did not provide enough information. Fifteen studies reported blinding of participants and outcome assessors.Topical antibiotic treatment showed better cure rates than placebo (pooled risk ratio (RR) 2. 24, 95% confidence interval (CI) 1.61 to 3.13) in 6 studies with 575 participants. In 4 studies with 440 participants, there was no clear evidence that either of the most commonly studied topical antibiotics (mupirocin and fusidic acid) was more effective than the other (RR 1.03, 95% CI 0.95 to 1.11).In 10 studies with 581 participants, topical mupirocin was shown to be slightly superior to oral erythromycin (pooled RR 1.07, 95% CI 1.01 to 1.13). There were no significant differences in cure rates from treatment with topical versus other oral antibiotics. There were, however, differences in the outcome from treatment with different oral antibiotics: penicillin was inferior to erythromycin, in 2 studies with 79 participants (pooled RR 1.29, 95% CI 1.07 to 1.56), and cloxacillin, in 2 studies with 166 participants (pooled RR 1.59, 95% CI 1.21 to 2.08).There was a lack of evidence for the benefit of using disinfectant solutions. When 2 studies with 292 participants were pooled, topical antibiotics were significantly better than disinfecting treatments (RR 1.15, 95% CI 1.01 to 1.32).The reported number of side-effects was low, and most of these were mild. Side-effects were more common for oral antibiotic treatment compared to topical treatment. Gastrointestinal effects accounted for most of the difference.Worldwide, bacteria causing impetigo show growing resistance rates for commonly used antibiotics. For a newly developed topical treatment, retapamulin, no resistance has yet been reported.

AUTHORS' CONCLUSIONS

There is good evidence that topical mupirocin and topical fusidic acid are equally, or more, effective than oral treatment. Due to the lack of studies in people with extensive impetigo, it is unclear if oral antibiotics are superior to topical antibiotics in this group. Fusidic acid and mupirocin are of similar efficacy. Penicillin was not as effective as most other antibiotics. There is a lack of evidence to support disinfection measures to manage impetigo.

Treatment of skin and soft tissue infections in the elderly: A review

BACKGROUND

Skin and soft tissue infections (SSTIs) have become the second most common type of infection among persons residing in long-term care facilities.

OBJECTIVE

The purpose of this article was to review the latest information on SSTIs among the elderly, including age-related changes, challenges, and treatment strategies in the era of emerging bacterial resistance.

METHODS

Relevant information was identified through a search of MEDLINE (1970-April 2010), International Pharmaceutical Abstracts (1970-April 2010), and Google Scholar using the terms skin and soft tissue infection, skin and skin structure infection, cellulitis, treatment guidelines, and elderly. Additional publications were found by searching the reference lists of the identified articles. Trials published since 1970 were selected for this review if they prospectively evaluated mostly adults (≥18 years of age), included >50 patients, and reported diagnostic criteria as well as clinical outcomes in patients treated for simple or complicated SSTIs.

RESULTS

Fifty-eight of 664 identified studies were selected and included in this review. A search of the literature did not identify any prospective clinical trials that were conducted exclusively in the elderly. Information on the treatment of SSTIs in the elderly was based solely on clinical studies that were conducted in adults in general. As recommended by the Infectious Diseases Society of America (IDSA) 2008 update, SSTIs should be suspected in elderly patients who have skin lesions and present with a decline in functional status, with or without fever. Patients who present with symptoms of systemic toxicity should be hospitalized for further evaluation. Current challenges in the management of SSTIs include the rapid emergence of community-acquired, methicillin-resistant Staphylococcus aureus (CA-MRSA), the emergence of macrolide-resistant streptococci within the past decade, and the lack of a reliable algorithm to differentiate potentially life-threatening SSTIs that require aggressive interventions and prompt hospitalization from those that can be managed in an outpatient setting. S aureus was the most common cause of SSTIs, being isolated in 42.8% (5015/11,723) of wounds, followed by streptococci. Common SSTIs in the elderly such as shingles, diabetic foot infections, infected pressure ulcers, and scabies, and their treatment were also discussed. Based on reviews of published trials, treatment of simple SSTIs generally consisted of administration of agents with activity against S aureus and Streptococcus species such as a penicillinase-resistant β-lactam, a first-generation cephalosporin, or clindamycin. Broadening of the antimicrobial spectrum to include gram-negative and anaerobic organisms should be implemented for complicated SSTIs such as diabetic foot infections and infected pressure ulcers. Local rates of MRSA, CA-MRSA, and macrolide-resistant streptococci should be considered when selecting empiric therapy.

CONCLUSIONS

A search of the literature did not identify any prospective clinical trials on the treatment of SSTIs in the elderly; therefore, it is recommended to follow treatment based on the current IDSA guidelines. More research and publications are needed to establish proper selection of antimicrobial agents, treatment strategies, and duration of therapy of SSTIs in the elderly population.

The role of beta-hemolytic streptococci in causing diffuse, nonculturable cellulitis: a prospective investigation

Staphylococcus aureus and beta-hemolytic streptococci (BHS) are the 2 main types of bacteria causing soft-tissue infections. Historically, BHS were believed to be the primary cause of diffuse, nonculturable cellulitis. However, with the recent epidemic of community-associated methicillin-resistant S aureus (MRSA) causing culturable soft-tissue infections, it is currently unclear what role either of these bacteria has in cases where the cellulitis is diffuse and nonculturable. This uncertainty has led to broad-spectrum and haphazard use of antibiotics for this infection type, which has led to increased risk of adverse drug reactions, health care costs, and emergence of resistance in bacteria. To investigate this issue, we conducted a prospective investigation between December 2004 and June 2007, enrolling all adult patients admitted to the inpatient service at the Olive View-UCLA Medical Center, a county hospital of Los Angeles, with diffuse, nonculturable cellulitis. Acute and convalescent serologies for anti-streptolysin-O and anti-DNase-B antibodies were obtained. Patient data were analyzed for response to beta-lactam antibiotics. The primary outcome was the proportion of these cases caused by BHS, as diagnosed by serologies and/or blood cultures, and the secondary outcome was the response rate of patients to beta-lactam antibiotics. Of 248 patients enrolled, 69 were dropped from analysis because of loss to follow-up or exclusion criteria. Of the 179 remaining patients, 73% of nonculturable cellulitis cases were caused by BHS. Analysis of outcomes to beta-lactam antibiotic treatment revealed that patients diagnosed with BHS had a 97% (71/73) response, while those who did not have BHS had a 91% (21/23) response, with an overall response rate of 95.8% (116/121). Results of this large, prospective study show that diffuse, nonculturable cellulitis is still mainly caused by BHS, despite the MRSA epidemic, and that for this infection type, treatment with beta-lactam antibiotics is still effective. A cost-effective, evidence-based algorithm can be useful for the empiric management of uncomplicated soft-tissue infections based on the presence or absence of a culturable source.

Efficacy and tolerability of cefditoren pivoxil in uncomplicated skin and skin structure infections in Indian patients

Background:

Uncomplicated skin and skin structure infections (uSSSI) are commonly encountered community-acquired infections and are typically confined to the superficial layers of the skin. Hence, they seldom lead to the destruction of skin structures.

Aims:

To evaluate the efficacy and tolerability of cefditoren pivoxil in uSSSI in Indian patients.

Methods:

One hundred and seventy-eight patients diagnosed with uncomplicated SSSI were enrolled in this randomized, comparative, multicentric study. Patients received either cefditoren pivoxil or cefdinir for ten days. Efficacy was assessed both clinically and microbiologically. Safety evaluation consisted of reporting of type, frequency, severity, and causal relationship of adverse events.

Results:

One hundred and fifty-one patients completed the study. Clinical and bacteriological efficacy of cefditoren pivoxil was comparable to that of cefdinir in the treatment of uSSSI. One hundred and five patients were eligible for per protocol (PP) analysis of bacteriological outcome and clinical efficacy. Clinical cure or improvement was achieved in 98.00% patients treated with cefditoren pivoxil and 98.18% patients treated with cefdinir. In the modified Intent to Treat (mITT) patient population, clinical cure or improvement was recorded in 97.33% patients treated with cefditoren pivoxil and 96.20% patients treated with cefdinir. Microbiological eradication (or presumed eradication) was recorded in 88.00% patients treated with cefditoren pivoxil and 94.55% patients treated with cefdinir. The above differences in the outcome rates between the two drugs were not statistically significant. Six adverse events (AEs) (two in cefditoren group and four in cefdinir group) were reported in this study.

Conclusion:

Cefditoren pivoxil 200 mg b.i.d. was effective and well tolerated in the treatment of uSSSI.

Interventions for cellulitis and erysipelas

BACKGROUND

Cellulitis and erysipelas are now usually considered manifestations of the same condition, a skin infection associated with severe pain and systemic symptoms. A range of antibiotic treatments are suggested in guidelines.

OBJECTIVES

To assess the efficacy and safety of interventions for non-surgically-acquired cellulitis.

SEARCH STRATEGY

In May 2010 we searched for randomised controlled trials in the Cochrane Skin Group Specialised Register, the Cochrane Central Register of Controlled Trials in The Cochrane Library, MEDLINE, EMBASE, and the ongoing trials databases.

SELECTION CRITERIA

We selected randomised controlled trials comparing two or more different interventions for cellulitis.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data.

MAIN RESULTS

We included 25 studies with a total of 2488 participants. Our primary outcome 'symptoms rated by participant or medical practitioner or proportion symptom-free' was commonly reported. No two trials examined the same drugs, therefore we grouped similar types of drugs together.Macrolides/streptogramins were found to be more effective than penicillin antibiotics (Risk ratio (RR) 0.84, 95% CI 0.73 to 0.97). In 3 trials involving 419 people, 2 of these studies used oral macrolide against intravenous (iv) penicillin demonstrating that oral therapies can be more effective than iv therapies (RR 0.85, 95% CI 0.73 to 0.98).Three studies with a total of 88 people comparing a penicillin with a cephalosporin showed no difference in treatment effect (RR 0.99, 95% CI 0.68 to 1.43).Six trials which included 538 people that compared different generations of cephalosporin, showed no difference in treatment effect (RR 1.00, 95% CI 0.94 to1.06).We found only small single studies for duration of antibiotic treatment, intramuscular versus intravenous route, the addition of corticosteroid to antibiotic treatment compared with antibiotic alone, and vibration therapy, so there was insufficient evidence to form conclusions. Only two studies investigated treatments for severe cellulitis and these selected different antibiotics for their comparisons, so we cannot make firm conclusions.

AUTHORS' CONCLUSIONS

We cannot define the best treatment for cellulitis and most recommendations are made on single trials. There is a need for trials to evaluate the efficacy of oral antibiotics against intravenous antibiotics in the community setting as there are service implications for cost and comfort.

Update of cefditoren activity tested against community-acquired pathogens associated with infections of the respiratory tract and skin and skin structures, including recent pharmacodynamic considerations

Antimicrobial resistance rates have noticeably increased among commonly isolated species associated with respiratory tract infections and skin and skin structure infections, particularly Streptococcus pneumoniae and Staphylococcus aureus. Cefditoren, an oral 3rd-generation-like cephalosporin, has been shown to be very active against many Gram-positive and Gram-negative species with favorable attributes including bactericidal activity and stability against many beta-lactamase enzymes. Clinical trial data worldwide support the use of cefditoren for infections and species that have been approved by the US Food and Drug Administration (US-FDA). This review and a contemporary study report provide an update of clinical trial and in vitro data for cefditoren especially against pathogens within the spectrum of activity since 2002. A large collection of 7279 clinical isolates collected during 2002 and 2003 from medical centers in North and Latin America and Europe were tested to confirm cefditoren potency and spectrum compared with other oral cephalosporins and other class agents. Isolates were tested at a reference laboratory using reference broth microdilution methods. Cefditoren was shown to be active against nearly all (>99%) isolates of penicillin-susceptible S. pneumoniae isolates (MIC(90), < or = 0.03 microg/mL) and was the most potent orally administered cephalosporin against this organism. Cefditoren was the most active oral cephem tested against Haemophilus influenzae (MIC(90), < or = 0.03 microg/mL) and had >99% activity versus both beta-lactamase-positive and beta-lactamase-negative isolates. The potency of cefditoren (MIC(90), 0.5 microg/mL) was similar to that of amoxicillin/clavulanate and cefdinir (MIC(90), 0.25 microg/mL) when tested against Moraxella catarrhalis. Cefditoren was the most potent cephalosporin tested against oxacillin-susceptible S. aureus with an MIC(90) value of only 1 microg/mL, and it was 100% active against the tested beta-hemolytic streptococci. Using the data generated from the large collection of isolates tested in this global surveillance collection, as well as other summarized supporting studies and clinical trial information, we show that cefditoren has sustained in vitro activity and documented clinical efficacy for indications that have been approved by regulators (US-FDA).

Antimicrobial activity of cefditoren tested against contemporary (2004-2006) isolates of Haemophilus influenzae and Moraxella catarrhalis responsible for community-acquired respiratory tract infections in the United States

Among orally administered cephalosporins, aminopenicillins (+/- clavulanate), and macrolides, cefditoren was the most potent agent against Haemophilus influenzae (MIC(50/90), < or =0.008/0.03 microg/mL; 316 isolates including 100 beta-lactamase-positive and 10 beta-lactamase-negative ampicillin-resistant [BLNAR]) and was 32-, 64-, and 512-fold more potent than cefdinir, cefuroxime, and cefprozil, respectively. Cefditoren (MIC(50), 0.03 microg/mL) was also > or =32-fold more active against BLNAR phenotypes, although newer macrolides provided complete coverage against these strains. All Moraxella catarrhalis isolates were inhibited by cefditoren (0.5 microg/mL), including beta-lactamase producers (MIC(50), 0.12 vs < or =0.008 microg/mL). Cefditoren retains potent activity against respiratory tract isolates in the United States, including those with resistance phenotypes.

Use of population pharmacokinetic modeling and Monte Carlo simulation to describe the pharmacodynamic profile of cefditoren in plasma and epithelial lining fluid

Cefditoren is a broad-spectrum, oral cephalosporin that is highly active against clinically relevant respiratory tract pathogens, including multidrug-resistant Streptococcus pneumoniae. This study described its pharmacodynamic profile in plasma and epithelial lining fluid (ELF). Plasma and ELF pharmacokinetic data were obtained from 24 patients under fasting conditions. Cefditoren and urea concentrations were determined in plasma and bronchoalveolar lavage fluid by liquid chromatography-tandem mass spectrometry. Concentration-time profiles in plasma and ELF were modeled using a model with three disposition compartments and first-order absorption, elimination, and transfer. Pharmacokinetic parameters were identified in a population pharmacokinetic analysis (big nonparametric adaptive grid with adaptive gamma). Monte Carlo simulation (9,999 subjects) was performed with the ADAPT II program to estimate the probability of target attainment at which the free-cefditoren plasma concentrations (88%) protein binding and total ELF concentrations exceeded the MIC for 33% of the dosing interval for 400 mg cefditoren given orally every 12 h. After the Bayesian step, the overall fits of the model to the data were good, and plots of predicted versus observed concentrations for plasma and ELF showed slopes and intercepts very close to the ideal values of 1.0 and 0.0, respectively. In the plasma probability of target attainment analysis, the probability of achieving a time for which free, or unbound, plasma concentration exceeds the MIC of the organism for 33% of the dosing interval was <80% for a MIC of >0.06 mg/liter. Similar to plasma, the probability of achieving a time above the MIC of 33% was <80% for MIC of >0.06 mg/liter in ELF. Cefditoren was found to have a low probability of achieving a bacteriostatic effect against MICs of >0.06 mg/liter, which includes most S. pneumoniae isolates with intermediate susceptibility to penicillin, when given in the fasting state in both plasma and ELF.

Oral β-lactams applied to uncomplicated infections of skin and skin structures

Uncomplicated skin and skin structure infections (uSSSIs) include impetigo, erysipelas, folliculitis, simple abscesses, and cellulitis. Their common bacterial causative agents include Staphylococcus aureus and Streptococcus pyogenes. Current guidelines predate the widespread occurrences of methicillin-resistant S. aureus (MRSA) as a community-acquired pathogen and include dicloxacillin, cephalexin, erythromycin, clindamycin, and amoxicillin/clavulanic acid, all orally, or mupirocin ointment applied topically, for impetigo. For other uSSSI, recommendations are based on the probability of the infection being caused by MRSA. If methicillin-susceptible S. aureus (MSSA) are known or suspected, the oral agents recommended include clindamycin, dicloxacillin, cephalexin, doxycycline, minocycline, and trimethoprim-sulfamethoxazole (SXT). For MRSA, recommended oral agents are linezolid, clindamycin, doxycycline, minocycline, and SXT. Because community-acquired MRSA infections now predominate in patients with abscesses in the United States, agents recommended for MRSA should be used for this indication. Local susceptibility patterns should guide empiric therapy. However, no placebo-controlled trials of uSSSI are available, and the evidence used to generate these recommendations is based on comparative noninferiority studies, often with wide noninferiority margins and confidence intervals. The evidence used in developing current guidelines therefore has significant limitations. Further studies, such as superiority outcome studies, placebo-controlled studies, measurement of time to resolution, or other novel approaches, are needed to resolve these treatment dilemmas. Until such studies are performed, the best surrogate available for predicting clinical outcome is application of pharmacokinetic and pharmacodynamic principles; these describe in vivo drug behavior and allow determination of susceptibility breakpoints for predicting in vivo antimicrobial efficacy via attainment of antimicrobial targets.

Adverse events associated with the use of oral cephalosporins/cephems

Historically, oral cephalosporins represent one of the most widely used and safest classes of antimicrobials available. Typical adverse events have included nausea, vomiting, diarrhea, and hypersensitivity reactions. Other more serious events such as pseudomembranous colitis, although infrequent, may occur. The exact type and incidence of adverse events varies depending on the cephalosporin being administered. Differences in adverse event profiles may also vary by age of the patient. Reactions are usually not severe and often do not require termination of therapy. The purpose of this review is to present to healthcare providers the historical safety profile of the most commonly used oral cephalosporins.

Cefdinir vs. cephalexin for mild to moderate uncomplicated skin and skin structure infections in adolescents and adults

OBJECTIVES

To compare the efficacy and safety of cefdinir to that of cephalexin in adolescents and adults with mild to moderate uncomplicated skin and skin structure infections (USSSI).

RESEARCH DESIGN AND METHODS

This was an investigator-blinded, multicenter study in which patients at least 13 years of age with USSSI were randomized to receive 10 days of cefdinir 300 mg twice daily (BID) or cephalexin 250 mg four times daily (QID). Patients were evaluated at baseline, by telephone on Days 3-5, and during office visits on Days 12-14 (end-of-therapy [EOT] visit) and Days 17-24 (test-of-cure [TOC] visit).

MAIN OUTCOME MEASURES

Clinical response was evaluated at the TOC visit. Patient reported outcomes, including a usefulness questionnaire, were also assessed.

RESULTS

Three hundred and ninety-one patients were treated. The treatment groups were well matched with regard to demographic characteristics and types of infection. Abscess(es) (26%), wound infection (24%), and cellulitis (21%) were the most common infections. At the TOC visit, the clinical cure rate for both treatment groups was 89% (151/170 for cefdinir and 154/174 for cephalexin) in clinically evaluable patients (95% CI for difference in cure rates [-6.7 to 7.3]). In the intent-to-treat analysis, cure rates were 83% for cefdinir vs. 82% for cephalexin. Clinical cure rates for infections caused by methicillin-susceptible (MSSA) and methicillin-resistant (MRSA) Staphylococcus aureus were 93% (37/40) and 92% (35/38) for cefdinir vs. 91% (29/32) and 90% (37/41) for cephalexin (p > 0.999 comparing treatment groups for MSSA; p > 0.999 for MRSA). The usefulness questionnaire demonstrated that cefdinir was more highly rated in the mean composite score (87.4 vs. 83.6, p = 0.04), with the difference primarily due to the respondents' preference for the convenience of taking the study medication (mean score 93.5 vs. 74.1 for cephalexin, p < 0.001). The study had the following limitations: the requirement for culture at baseline likely skewed the enrollment of patients towards those with abscesses; the results of culture in patients with USSSIs are often nonspecific; in some patients entering the study with a diagnosis of cellulitis, the cellulitis was associated with an abscess; and, incision and drainage (I&D), spontaneous drainage, and needle aspiration are likely to have contributed to clinical response for purulent infections, and in particular MRSA-associated infections. Both study drugs were well tolerated. The most common treatment-related adverse events were diarrhea (10% cefdinir, 4% cephalexin, p = 0.017), nausea (3% and 6%, respectively, p = 0.203), and vaginal mycosis (3% and 6% of females, respectively, p = 0.500).

CONCLUSIONS

This study demonstrated that empiric coverage of USSSIs with cephalosporin therapy remains an appropriate clinical strategy. MRSA infections responded well in both arms of the study, suggesting that the choice of a cephalosporin did not adversely affect patient outcome. However, cephalosporins do not have accepted, clinically relevant in vitro activity against MRSA. Hence, the clinical response rates seen in this study against MRSA infections must be interpreted with caution. Cefdinir was more highly rated than cephalexin in a composite usefulness assessment.

Development of a Health-Related Quality of Life Questionnaire (HRQL) for patients with Extremity Soft Tissue Infections (ESTI)

Background

Past clinical trials of antimicrobial treatment in soft tissue infections have focused on non-standardized clinical and physiological outcome variables, and have not considered the subjective experience of patients. The objective of this study was to develop a health-related quality of life questionnaire (HRQL) for patients with extremity soft tissue infections (ESTI) for future use in clinical trials.

Methods

The design of this study followed published guidelines and included item generation, item reduction, and questionnaire preparation. Study subjects were consenting English-speaking adults with acute ESTI requiring prescription of at least two days of outpatient intravenous antibiotic therapy.

Results

A list of 49 items that adversely impact the quality of life of patients with ESTI was generated by literature review, informal health professional feedback, and semi-structured interviews with twenty patients. A listing of these items was then administered to 95 patients to determine their relative importance on quality of life. A questionnaire was prepared that included the twenty most important items with a 5-point Likert scale response. Questionnaire domains included physical symptoms, problems performing their activities of daily living, impairment of their emotional functioning, and difficulties in their social interactions as related to their ESTI. The final questionnaire was pre-tested on a further ten patients and was named the ESTI-Score.

Conclusion

The ESTI-Score is a novel instrument designed to quantify the impact of ESTI on quality of life. Future study is required to determine its validity and responsiveness before use as an outcome measure in clinical trials.

Cephalosporins for uncomplicated skin and skin structure infections in emerging community-acquired MRSA

The treatment of community uncomplicated skin and skin structure infections (uSSSIs) mandates that treatment should be based on careful consideration of infection attributes and patient characteristics, particularly in this era of community-acquired MRSA as an emerging pathogen. However, as most uSSSIs in the community continue to be caused by methicillin-susceptible Staphylococcus aureus or streptococci, effective treatment against these key pathogens should aim to achieve prompt eradication, along with minimal risk of antimicrobial resistance. Cephalosporins are an effective broad-spectrum empirical treatment for uSSSIs, with considerable activity against methicillin-susceptible S. aureus. In addition, the use of antimicrobial agents in infective strains that may be resistant does not appear to be associated with adverse patient-reported outcomes, suggesting that cephalosporins may still be effective in treating community-acquired MRSA-associated SSSIs.

Staphylococcal skin infections in children: rational drug therapy recommendations

Staphylococcus aureus remains one of the most common and troublesome of bacteria causing disease in humans, despite the development of effective antibacterials and improvement in hygiene. The organism is responsible for over 70% of all skin and soft tissue infections in children and accounts for up to one-fifth of all visits to pediatric clinics. Skin and soft tissue infections that are predominantly caused by S. aureus include bullous and non-bullous impetigo, folliculitis, furunculosis, carbunculosis, cellulitis, surgical and traumatic wound infections, mastitis, and neonatal omphalitis. Other skin and soft tissue infections may also be caused by S. aureus but are often polymicrobial in origin and require special consideration. These include burns, decubitus ulcers (particularly in the perianal region), puncture wounds of the foot, as well as human and mammalian bites. Treatment of staphylococcal skin infections varies from topical antiseptics to prolonged intravenous antibacterials, depending on severity of the lesions and the health of the child. The treatment of choice for oral antibacterials remains the penicillinase-resistant penicillins such as flucloxacillin. Cefalexin and erythromycin are suitable cost-effective alternatives with broader cover, although care must be taken with the use of macrolides because of development of resistance to multiple families of antibacterials, particularly the lincosamides. Other cephalosporins such as cefadroxil and cefprozil are also effective, can be given once daily and have a better tolerability profile -- while azithromycin has a further advantage of a 3-day course. However, all of these agents are more expensive. Although the antibacterials have been given for 10 days in most clinical trials, there is no evidence that this duration is more effective than a 7-day course. In children requiring intravenous therapy, ceftriaxone has a major advantage over other antibacterials such as sulbactam/ampicillin and cefuroxime in that it can be given once daily and may, therefore, be suitable for outpatient treatment of moderate-to-severe skin infections. Newer-generation cephalosporins and loracarbef are also effective and have a broader spectrum of activity, but do not offer any added benefit and are significantly more expensive. Skin and soft tissue infections due to methicillin-resistant S. aureus (MRSA) are still relatively uncommon in children. Well children with community-acquired MRSA infections can be treated with clindamycin or trimethoprim-sulfamethoxazole (cotrimoxazole), but must be observed closely for potentially severe adverse effects. In severe infections, vancomycin remains the treatment of choice, while intravenous teicoplanin and clindamycin are suitable alternatives. Linezolid and quinupristin/dalfopristin are currently showing great promise for the treatment of multi-resistant Gram-positive infections. While the choice of antibacterial is important, supportive management, including removal of any infected foreign bodies, surgical drainage of walled-off lesions, and regular wound cleaning, play a vital role in ensuring cure.

Flucloxacillin alone or combined with benzylpenicillin to treat lower limb cellulitis: a randomised controlled trial

OBJECTIVE

To determine whether using intravenous benzylpenicillin in addition to intravenous flucloxacillin would result in a more rapid clinical response in patients with lower limb cellulitis.

METHODS

This was a randomised controlled trial set in an inner city teaching hospital, comprising 81 patients with lower limb cellulitis requiring intravenous antibiotics. The main outcome measure was the mean number of doses of antibiotic required until clinical response.

RESULTS

The mean number of doses required was 8.47 (95% confidence interval (CI) 7.09 to 9.86) in the benzylpenicillin and flucloxacillin combined group. In the flucloxacillin only group it was 8.71 doses (95% CI 6.90 to 10.5), a mean difference of -0.24 doses (95% CI -2.48 to 2.01, p = 0.83). Other markers of treatment efficacy showed no difference between groups at review the following day; temperature decrease (mean difference -0.07 degrees C, 95% CI -0.76 to 0.62, p = 0.84), or diameter decrease of affected area (mean difference -34 mm, 95% CI -99 to 31, p = 0.30). Patient subjective assessments were also similar between the different drug regimen; improvement on a visual analogue scale of pain/discomfort from admission to first review (mean difference 10 mm, 95% CI -12.6 to 14.2, p = 0.91) and on second review (mean difference 15 mm, 95% CI -18.6 to 21.6, p = 0.88). Patient overall subjective feelings of improvement on first review (p = 0.32) and on second review (p = 0.64) were also similar.

CONCLUSIONS

This study provides no evidence to support the addition of intravenous benzylpenicillin to intravenous flucloxacillin in the treatment of lower limb cellulitis.

Spotlight on cefditoren pivoxil in bacterial infections

Cefditoren pivoxil (Spectracef, Meiact) is a third-generation oral cephalosporin with a broad spectrum of activity against pathogens, including both Gram-positive and -negative bacteria, and is stable to hydrolysis by many common beta-lactamases. Cefditoren pivoxil is approved for use in the treatment of acute exacerbations of chronic bronchitis (AECB), mild-to-moderate community-acquired pneumonia (CAP), acute maxillary sinusitis, acute pharyngitis/tonsillitis, and uncomplicated skin and skin structure infections (indications may differ between countries). In clinical trials in adults and adolescents, cefditoren pivoxil demonstrated good clinical and bacteriological efficacy in AECB, CAP, acute maxillary sinusitis, acute pharyngitis/tonsillitis, and uncomplicated skin and skin structure infections, and was generally well tolerated. Thus, cefditoren pivoxil is a good option for the treatment of adult and adolescent patients with specific respiratory tract or skin infections, particularly if there is concern about Streptococcus pneumoniae with decreased susceptibility to penicillin, or beta-lactamase-mediated resistance among the common community-acquired pathogens.

Cefditoren pivoxil: a review of its use in the treatment of bacterial infections

Cefditoren pivoxil (Spectracef, Meiact) is a third-generation oral cephalosporin with a broad spectrum of activity against pathogens, including both Gram-positive and -negative bacteria, and is stable to hydrolysis by many common beta-lactamases. Cefditoren pivoxil is approved for use in the treatment of acute exacerbations of chronic bronchitis (AECB), mild-to-moderate community-acquired pneumonia (CAP), acute maxillary sinusitis, acute pharyngitis/tonsillitis and uncomplicated skin and skin structure infections (indications may differ between countries). In clinical trials in adults and adolescents, cefditoren pivoxil demonstrated good clinical and bacteriological efficacy in AECB, CAP, acute maxillary sinusitis, acute pharyngitis/tonsillitis and uncomplicated skin and skin structure infections and was generally well tolerated. Thus, cefditoren pivoxil is a good option for the treatment of adult and adolescent patients with specific respiratory tract or skin infections, particularly if there is concern about Streptococcus pneumoniae with decreased susceptibility to penicillin, or beta-lactamase-mediated resistance among the common community-acquired pathogens.

Beta-lactam antibiotics: newer formulations and newer agents

beta-Lactam antibiotics share a common structure and mechanism of action, although they differ in their spectrum of antimicrobial activity and utility in treating different infections. The current classes include the penicillins, the penicillinase-resistant penicillins, the extended- spectrum penicillins, the cephalosporins, the carbapenems, and the monobactams. This article discusses some of the newest beta-lactams available for use in the United States: ertapenem, cefditoren, and cefepime. A new formulation of amoxicillin-clavulanate, which contains higher doses of amoxicillin, is also discussed.