Once-daily intravenous cefazolin plus oral probenecid is equivalent to once-daily intravenous ceftriaxone plus oral placebo for the treatment of moderate-to-severe cellulitis in adults

Community antibiotic management of skin infections in the Torres Strait

BACKGROUND

There is a high burden of skin and soft tissue infections (SSTI) - including cellulitis - among Aboriginal and Torres Strait Islander peoples living in remote communities. In tropical environments, such as the Torres Strait, cellulitis accounts for 37% of potentially preventable hospitalisations. This study aimed to evaluate the safety, effectiveness and community acceptance of outpatient antibiotic treatment for the management of skin infections in the Torres Strait.

CONCLUSIONS

Outpatient management of skin infection in the Torres Strait is effective, safe and appreciated by patients.

METHODS

This was a 12-month prospective, observational study commencing in January 2019 involving 295 adults with a skin infection across the Torres Strait.

RESULTS

Most (276/295 (94%)) participants were treated successfully in the community. Of 295 enrolled patients, 151 of 295 (51%) had cellulitis, 59 of 295 (20%) had a skin abscess and 85 of 295 (28%) had a wound infection. Of the 77 of 278 (27%) infections accompanied by systemic features, 63 of 77 (82%) were managed in the community. Staphylococcus aureus was the most frequent isolate, at 165 of 261 (63%); 56 of 165 (33%) were methicillin resistant. In the 276 community-managed cases, oral trimethoprim/sulfamethoxazole was initially used in 159 (57%), oral flucloxacillin in 75 (27%) and intravenous cefazolin plus oral probenecid in 32 (13%). The clinical course was complicated in eight of 232 (3%) patients who had complete follow-up data: seven patients required hospitalisation after initial treatment in the communityand one had an antibiotic side-effect. All 232 patients with complete follow-up data were content with the care they received.

Exploring the advancements of Australian OPAT

Outpatient parenteral antimicrobial therapy (OPAT) in Australia has evolved from modest beginnings to a well-established health service with proven benefits in patient outcomes. This is a comprehensive review of the current state of art Australian OPAT with vignettes of the types of OPAT models of care, antimicrobial prescribing and antimicrobial use. In addition, we highlight the similarities and differences between OPAT to other countries and describe Australian OPAT experiences with COVID-19 and paediatrics. Australian OPAT continues to advance with OPAT antifungals, novel treatment options and upcoming high-impact research.

Addition of probenecid to oral β-lactam antibiotics: a systematic review and meta-analysis

OBJECTIVES

To explore the literature comparing the pharmacokinetic and clinical outcomes from adding probenecid to oral β-lactams.

METHODS

Medline and EMBASE were searched from inception to December 2021 for all English language studies comparing the addition of probenecid (intervention) with an oral β-lactam [flucloxacillin, penicillin V, amoxicillin (± clavulanate), cefalexin, cefuroxime axetil] alone (comparator). ROBINS-I and ROB-2 tools were used. Data on antibiotic therapy, infection diagnosis, primary and secondary outcomes relating to pharmacokinetics and clinical outcomes, plus adverse events were extracted and reported descriptively. For a subset of studies comparing treatment failure between probenecid and control groups, meta-analysis was performed.

RESULTS

Overall, 18/295 (6%) screened abstracts were included. Populations, methodology and outcome data were heterogeneous. Common populations included healthy volunteers (9/18; 50%) and those with gonococcal infection (6/18; 33%). Most studies were crossover trials (11/18; 61%) or parallel-arm randomized trials (4/18; 22%). Where pharmacokinetic analyses were performed, addition of probenecid to oral β-lactams increased total AUC (7/7; 100%), Cmax (5/8; 63%) and serum t½ (6/8; 75%). Probenecid improved PTA (2/2; 100%). Meta-analysis of 3105 (2258 intervention, 847 control) patients treated for gonococcal disease demonstrated a relative risk of treatment failure in the random-effects model of 0.33 (95% CI 0.20-0.55; I2 = 7%), favouring probenecid.

CONCLUSIONS

Probenecid-boosted β-lactam therapy is associated with improved outcomes in gonococcal disease. Pharmacokinetic data suggest that probenecid-boosted oral β-lactam therapy may have a broader application, but appropriately powered mechanistic and efficacy studies are required.

Optimizing antimicrobial use: challenges, advances and opportunities

An optimal antimicrobial dose provides enough drug to achieve a clinical response while minimizing toxicity and development of drug resistance. There can be considerable variability in pharmacokinetics, for example, owing to comorbidities or other medications, which affects antimicrobial pharmacodynamics and, thus, treatment success. Although current approaches to antimicrobial dose optimization address fixed variability, better methods to monitor and rapidly adjust antimicrobial dosing are required to understand and react to residual variability that occurs within and between individuals. We review current challenges to the wider implementation of antimicrobial dose optimization and highlight novel solutions, including biosensor-based, real-time therapeutic drug monitoring and computer-controlled, closed-loop control systems. Precision antimicrobial dosing promises to improve patient outcome and is important for antimicrobial stewardship and the prevention of antimicrobial resistance.

Probenecid effects on cephalexin pharmacokinetics and pharmacodynamics in healthy volunteers

OBJECTIVES

We evaluated the effects of probenecid on the Pharmaco Kinetics (PK) and pharmacodynamics (PD) of oral cephalexin in healthy volunteers.

METHODS

Cephalexin 1000 mg was administered orally to 11 healthy volunteers following a standardized meal, with and without probenecid 500 mg orally, on two separate days one week apart. Total plasma concentrations of cephalexin and probenecid over a 12 h period were measured by liquid chromatography tandem mass spectrometry. Standard pharmacokinetic measures and contemporary PK/PD targets were compared.

RESULTS

Probenecid increased the mean (95% CI) cephalexin area under the concentration-time curve (AUC_0-∞) 1.73-fold (1.61-1.85, p < 0.0001), peak concentration 1.37-fold (1.16-1.58, p < 0.01), time to peak concentration 1.45-fold (1.1-1.8, p < 0.01)_, and half-life 1.33-fold (1.03-1.62, p < 0.05). The effects resulted in clinically meaningful increases in the probability of PK/PD target attainment (PTA). As an example, the PTA of total concentrations above the minimum inhibitory concentration required to inhibit methicillin-susceptible Staphylococcus aureus isolates (MIC ≤ 8 mg/L) for 70% of a 6 h dose interval approached 100% for cephalexin + probenecid while for cephalexin alone it was <15%.

CONCLUSIONS

Probenecid prolonged and flattened the plasma concentration-time curve, enhancing the probability of attaining PK/PD targets. Co-administration of probenecid may expand the clinical benefits of oral cephalexin.

Population pharmacokinetics of free flucloxacillin in patients treated with oral flucloxacillin plus probenecid

Oral flucloxacillin may be coadministered with probenecid to reduce flucloxacillin clearance and increase attainment of pharmacokinetic-pharmacodynamic (PK/PD) targets. The aims of this study were to develop a population PK model of free flucloxacillin when administered orally with probenecid, and to identify optimal dosing regimens for this combination.

METHODS

We performed a prospective observational study of adults (45 participants) treated with oral flucloxacillin 1000 mg and probenecid 500 mg 8-hourly for proven or probable staphylococcal infections. Steady-state mid-dose-interval flucloxacillin measurements (45 concentrations) were combined with existing data from a crossover study of healthy participants receiving flucloxacillin with and without probenecid (11 participants, 363 concentrations). We developed a population pharmacokinetic model of free flucloxacillin concentrations within Monolix, and used Monte Carlo simulation to explore optimal dosing regimens to attain PK/PD targets proposed in the literature (free drug time above minimum inhibitory concentration).

RESULTS

Flucloxacillin disposition was best described by a 1-compartment model with a lag time and first-order absorption. Free flucloxacillin clearance depended on probenecid, allometrically-scaled fat free mass (FFM) and estimated glomerular filtration rate (eGFR). Predicted PK/PD target attainment was suboptimal with standard dosing regimens with flucloxacillin alone, but substantially improved in the presence of probenecid.

CONCLUSION

The simulation results reported can be used to identify dose regimens that optimise flucloxacillin exposure according to eGFR and FFM. Patients with higher FFM and eGFR may require the addition of probenecid and 6-hourly dosing to achieve PK/PD targets. The regimen was well-tolerated, suggesting a potential for further evaluation in controlled clinical trials to establish efficacy.

Prescribing Patterns and Patient Outcomes for Bone and Joint Infections Treated with Cefazolin and Probenecid: A Retrospective Observational Study

BACKGROUND

Previous studies have described the use of cefazolin with probenecid to treat uncomplicated skin and soft-tissue infections. Some prescribers are extrapolating from this evidence to treat more invasive infections, which have a greater potential for poor outcomes, including treatment failure that could lead to increased morbidity and mortality. Information supporting cefazolin with probenecid as effective treatment in this context is needed.

OBJECTIVES

To describe prescribing patterns and outcomes for patients who received cefazolin with probenecid for the treatment of bone and joint infections.

METHODS

This single-centre retrospective study involved adult outpatients for whom cefazolin and probenecid were prescribed for bone and joint infections between April 1, 2012, and March 31, 2017. Patient charts were reviewed, and data were collected for clinical and microbiological variables using a standardized data collection form.

RESULTS

In a total of 80 cases, the patient received cefazolin and probenecid for treatment of a bone or joint infection, of which 69 cases met the inclusion criteria. In most cases (n = 67), the patients were treated with cefazolin 2 g IV plus probenecid 1 g PO, both given twice daily. Completion of prescribed treatment occurred in 56 patient cases (81%), resolution of signs and symptoms in 53 (77%), readmission to hospital in 11 (16%), recurrence of infection in 6 (9%), and treatment failure requiring a change in therapy in 7 (10%).

CONCLUSIONS

The effectiveness of cefazolin and probenecid for the treatment of bone and joint infections appears to be similar to that of standard treatment, as reported in the literature. Antibiotic effectiveness is difficult to determine conclusively in a retrospective analysis, so these results should be interpreted with caution, but they may stimulate further research.

Intravenous (IV) cefazolin with oral probenecid: A novel daily regimen for the management of Methicillin Sensitive Staphylococcus aureus (MSSA) bacteremia in a patient with renal dysfunction

A 78 year old man developed a methicillin sensitive Staphylococcus aureus (MSSA) post-operative wound infection following an elective L2-L4 laminectomy. He was treated with surgical debridement which was to be followed by a planned 6 weeks course of cefazolin. However, two weeks post debridement, a follow-up MRI revealed an L3-L5 epidural abscess, septic arthritis and vertebral osteomyelitis prompting repeat surgical debridement. No purulence was noted, and operative cultures were negative for growth. His hospital course was complicated by acute kidney injury and a renal biopsy reveled crescentic glomerulonephritis consistent with post infectious glomerulonephritis. He was treated with daptomycin, followed by oral linezolid. Five months after his original laminectomy, he developed purulent drainage from his back wound. Blood cultures grew MSSA and a repeat aspirate done by interventional radiology also grew MSSA. He improved with nafcillin and was transitioned to telavancin on discharge to facilitate once daily treatment. While on telavancin he developed increasing back pain and fever. Therefore, the regimen was changed to IV cefazolin and oral probenecid for five weeks followed by oral cephalexin to complete a total of 12 weeks of therapy. There is no evidence of disease recurrence one year after completion of therapy. IV cefazolin with oral probenecid may represent a once daily IV treatment option for patients with MSSA bacteremia and kidney disease.

Is coverage of S. aureus necessary in cellulitis/erysipelas? A literature review

BACKGROUND

Empirical treatment of patients with cellulitis/erysipelas usually targets both streptococci and methicillin-sensitive S. aureus (MSSA). However, the recommendation to empirically cover MSSA is weak and based on low-quality evidence.

METHODS AND OBJECTIVE

A systematic review was conducted in PubMed and clinical trial registries to assess the role of S. aureus in cellulitis/erysipelas and the need for empirical MSSA coverage.

RESULTS

Combined microbiological and serological data, and response to penicillin monotherapy suggest that streptococci are responsible for the vast majority of cases of cellulitis/erysipelas. However, most cases are non-culturable and the specificity of microbiological and serological studies is questionable based on recent studies using molecular techniques. According to epidemiological data and three randomized controlled trials, empirical coverage of methicillin-resistant S. aureus (MRSA) is not recommended for most patients, despite the high prevalence of MRSA in many areas. If MRSA is indeed not an important cause of uncomplicated cellulitis/erysipelas, then the same may apply to MSSA. Based on indirect comparison of data from clinical studies, cure rates with penicillin monotherapy (to which most MSSA are resistant) are comparable to the cure rates reported in many studies using wider-spectrum antibiotics.

CONCLUSION

Considering the limitations of microbiological studies in identifying the pathogens responsible for cellulitis/erysipelas, treatment needs to be guided by clinical trials. Trials comparing penicillin or amoxicillin monotherapy to MSSA-covering regimens are needed to definitively answer whether empirical coverage of MSSA is needed and to identify the subset of patients that can be safely treated with penicillin or amoxicillin monotherapy.

Out Of Hospital And In Hospital Management Of Cellulitis Requiring Intravenous Therapy

Background

Cellulitis requiring intravenous therapy can be managed via out of hospital programs, but a high number of patients are still admitted to hospital.

Objective

We aimed to review the clinical features, management and outcomes of patients with cellulitis requiring intravenous therapy in a Hospital in the Home (HITH) program compared to patients who are admitted to hospital.

Methods

A prospective cohort study of patients with limb cellulitis requiring intravenous antibiotics was conducted at a metropolitan principal referral hospital.

Results

A total of 100 patients out of 113 eligible patients were recruited. Forty-eight were treated entirely in hospital and 52 were treated entirely or partially via HITH. Patients treated in hospital were older (mean 69.2 vs 56.7 years, p<0.001), less mobile, have more comorbidities (Charlson Comorbidity Index mean 2.2 vs 1.2, P=0.005) and more associated active illness. All patients with Eron Class III were admitted to hospital. Patients treated in hospital had a higher incidence of acute renal failure (27.1% vs 3.8%, p=0.001), nosocomial infection (10.4% vs 0.0%, P=0.023), and a higher 28-day hospital readmission rate (10.4% vs 0.0%, P=0.023).

Conclusion

Approximately half of the patients who require intravenous therapy can be treated via an out of hospital program. Patients admitted to hospital were more unwell and more likely to suffer complications. The presence of comorbid illness does not necessarily exclude participation in HITH and careful selection is essential to ensure safe outcomes.

Functionalization of PEO layer formed on Ti-15Mo for biomedical application

In the present work, deposition of poly(sebacic anhydride) PSBA loaded by amoxicillin, cefazolin, or vancomycin on a previously anodized Ti-15Mo surface is presented. PSBA loaded by the drug was deposited so as not to lose the functionality of the porous oxide layer microstructure. The morphology was evaluated using scanning electron microscopy, surface roughness, and wettability. The drug concentration was evaluated using high-performance liquid chromatography. It was determined that the drugs were loaded into coatings in the range of 35.2-122.87 μg/cm² of Ti sample. The drugs released more than 16% after 0.5 hr of the hybrid coating immersion in artificial saliva. After 3 days, the PSBA coatings were degraded by 51.3 mol %, and after 7 days by 77.8 mol %, which makes it possible to load the material by different, biologically active substances. An antimicrobial investigation of Staphylococcus aureus (DSM 24167) and Staphylococcus epidermidis (ATCC 700296) confirmed the activity of the hybrid layers against the pathogens. Hybrid layer with vancomycin best inhibits the adhesion of the bacteria, whereas coatings with amoxicillin and cefazolin showed a much better bactericidal activity. In this article, the difference in the obtained results is discussed, as well as the possibility of the application of this functional material in biomedicine.

Antibiotic treatment for 6 days versus 12 days in patients with severe cellulitis: a multicentre randomized, double-blind, placebo-controlled, non-inferiority trial

OBJECTIVES

To investigate whether antibiotic treatment of 6 days' duration is non-inferior to treatment for 12 days in patients hospitalized for cellulitis.

METHODS

This multicentre, randomized, double-blind, placebo-controlled, non-inferiority trial enrolled adult patients hospitalized for severe cellulitis who were treated with intravenous flucloxacillin. At day 6 participants with symptom improvement who were afebrile were randomized between an additional 6 days of oral flucloxacillin or placebo in a 1:1 ratio, stratified for diabetes and hospital. The primary outcome was cure by day 14, without relapse by day 28. Secondary outcomes included a modified cure assessment and relapse rate by day 90.

RESULTS

Between August 2014 and June 2017, 151 of 248 included participants were randomized. The intention-to-treat population consisted of 76 and 73 participants allocated to 12 and 6 days of antibiotic therapy, respectively (mean age 62 years, 67% males, 24% diabetics); 38/76 (50.0%) and 36/73 (49.3%) were cured in the 12- and 6-day groups respectively (ARR 0.7 percentage points, 95%CI: -15.0 to 16.3). Cure rates were 56/76 (73.7%) and 49/73 (67.1%) with the modified cure assessment (ARR 6.6, 95%CI: -8.0 to 20.8). After initial cure without relapse, day 90 relapse rates were higher in the 6-day group (6% versus 24%, p < 0.05).

CONCLUSIONS

Given the wide confidence intervals, we can neither confirm nor refute our hypothesis that 6 days of therapy is non-inferior to 12 days of therapy. However, a 6-day course resulted in significantly more frequent relapses by day 90. These findings require confirmation in future studies.

Probenecid and food effects on flucloxacillin pharmacokinetics and pharmacodynamics in healthy volunteers

OBJECTIVES

To measure the effect of probenecid, fasting and fed, on flucloxacillin pharmacokinetic and pharmacodynamic endpoints.

METHODS

Flucloxacillin 1000 mg orally was given to 11 volunteers alone while fasting ('flucloxacillin alone'), and with probenecid 500 mg orally while fasting ('probenecid fasting') and with food ('probenecid fed'). Flucloxacillin pharmacokinetic and pharmacodynamic endpoints were compared.

RESULTS

Probenecid, fasting and fed, increased free plasma flucloxacillin area under the concentration-time curve (zero to infinity) ∼1.65-fold (p < 0.01) versus flucloxacillin alone. Probenecid fed prolonged time to peak flucloxacillin concentrations ∼2-fold versus the other two regimens (p < 0.01). Probenecid fasting or fed increased free flucloxacillin concentrations exceeding 30%, 50% and 70% of the first 6, 8 and 12 h post-dose by 1.58- to 5.48-fold compared with flucloxacillin alone. As an example of this pharmacodynamic improvement, the probability of target attainment of free concentrations above the minimum inhibitory concentration for Staphylococcus aureus (0.5 mg/L) for 50% of a 6-hour dose interval was > 80% for flucloxacillin plus probenecid (fasting or fed) and < 20% for flucloxacillin alone.

CONCLUSIONS

Probenecid increased flucloxacillin exposure, with predicted pharmacodynamic effects greater than pharmacokinetic effects because of the altered shape of the concentration-time curve. Probenecid may improve the applicability of oral flucloxacillin regimens.

Lessons Learned From a Randomized Controlled Trial of Short-Course Intravenous Antibiotic Therapy for Erysipelas and Cellulitis of the Lower Limb (Switch Trial)

BACKGROUND

The diagnosis of cellulitis is made clinically without a gold standard diagnostic test, and cellulitis has many disease mimics. There is currently no consensus for optimal antimicrobial treatment duration or method of antimicrobial delivery.

METHODS

This was a randomized controlled open-label multicenter trial to determine the safety and efficacy of 24 hours of intravenous (IV) therapy compared with ≥72 hours of IV therapy, both followed by oral therapy to a maximum of 7-10 days' duration for the treatment of lower limb cellulitis.

RESULTS

Over 40 months, 80 patients were recruited. Thirty-nine patients were assigned to 24 hours of IV antibiotics and 41 to ≥72 hours of IV antibiotics. The mean duration (range) of IV antibiotics in the 24-hour group was 25.5 (17-40) hours, and in the ≥72-hour group it was 78 (41.5-210) hours. Three patients in the 24-hour arm and 4 patients in the ≥72-hour arm were excluded from the analysis due to withdrawal from the trial. Analysis of the remaining patients revealed that 6 patients (4 in the intervention arm and 2 in the control arm) did not achieve an adequate response to therapy. Only 1 patient experienced self-limiting adverse effects of treatment.

CONCLUSIONS

The noninferiority of short-course IV therapy cannot be determined from this trial. Challenges included resource limitations for recruitment, misdiagnosis, participant withdrawal, and subjective responses to therapy based on visual assessment by treating clinicians. Further studies are needed to determine if short-course IV therapy is a suitable treatment option.

AUSTRALIA COUNCIL OF CLINICAL TRIALS REGISTRY NO

ACTRN12613001366741.

Treatment failure definitions for non-purulent skin and soft tissue infections: a systematic review

OBJECTIVE

There is currently no uniform definition for antimicrobial treatment failure for adults with non-purulent skin and soft tissue infections (SSTIs). The objective of this systematic review was to identify treatment failure definitions and their common components in the literature.

METHODS

Five electronic databases were searched from inception to March 2019. Two independent reviewers identified studies involving adults (age ≥ 18 years) with non-purulent SSTIs in which antimicrobial treatment failure was a defined outcome. There were no language restrictions. Only randomized trials or observational studies were included.

RESULTS

After screening 4953 abstracts, 26 studies (N = 6629 patients) met full inclusion criteria. Reported treatment failure ranged from 0 to 29.5%. The most common definition components were hospital admission (78.9%), change in antibiotics (65.4%), and persistent or worsening signs and symptoms of infection (34.6%). Only one study listed specific criteria for persistent or worsening signs and symptoms of infection.

CONCLUSIONS

For studies involving non-purulent SSTIs, the outcome of treatment failure is inconsistently defined and reported failure rates are highly variable. This systematic review has highlighted the need for more robust treatment failure definitions for non-purulent SSTIs. Research should focus on the development of a uniform treatment failure definition that should be used in future studies.

Continuous cefazolin infusion versus cefazolin plus probenecid for the ambulatory treatment of uncomplicated cellulitis: A retrospective cohort study

BACKGROUND

The preferred ambulatory IV therapy for cellulitis is often once-daily cefazolin combined with once-daily oral probenecid (C+P). However, due to a national probenecid drug shortage in 2011, our centre developed a replacement protocol for the administration of cefazolin continuous infusion (CCI) using elastomeric infusers. Our goal was to compare treatment efficacy, duration of IV therapy, and recurrence associated with CCI and C+P using retrospective data from our centre.

METHODS

We conducted a non-inferiority single-centre retrospective cohort study of emergency department medical records. Patients received either C+P (cefazolin 2 g IV once daily plus probenecid 1 g PO once daily) or CCI (cefazolin 2 g IV loading dose, followed by cefazolin 6 g IV via continuous infusion over 24 hours, via an elastomeric infuser). We compared treatment efficacy, duration of IV therapy, and recurrence rates.

RESULTS

 total of 203 patients were analyzed, with 107 included in the CCI arm and 96 in the C+P arm. Overall, CCI users and C+P users were comparable in their sociodemographic and clinical variables measured at admission. We observed increased odds of achieving successful treatment among the CCI group, however it did not reach statistical significance (odds ratio [OR] 2.25; 95% CI 0.84 to 6.07). Recurrence rates were similar between both groups (OR 1.91; 95% CI 0.32 to 11.31). The average duration of IV therapy was similar between groups (p = 0.6).

CONCLUSIONS

ith results suggesting that CCI was non-inferior to C+P, and that both approaches required similar treatment durations, CCI could represent an acceptable alternative to C+P for the ambulatory IV treatment of cellulitis.

Intravenous cefazolin plus oral probenecid versus oral cephalexin for the treatment of skin and soft tissue infections: a double-blind, non-inferiority, randomised controlled trial

OBJECTIVE

The purpose of our study was to determine if cephalexin 500 mg orally four times daily was non-inferior to cefazolin 2 g intravenously daily plus probenecid 1 g orally daily in the management of patients with uncomplicated mild-moderate skin and soft tissue infection (SSTI) presenting to the ED.

METHODS

This was a prospective, multicentre, double dummy-blind, randomised controlled non-inferiority trial conducted at two tertiary care teaching hospitals in Canada. Patients were enrolled if they presented to the ED with an uncomplicated SSTI, and randomly assigned in a 1:1 fashion to oral cephalexin or intravenous cefazolin plus oral probenecid for up to 7 days. The primary outcome was failure of therapy at 72 hours. Clinical cure at 7 days, intravenous to oral medication transition admission to hospital and adverse events were also evaluated.

RESULTS

206 patients were randomised with 104 patients in the cephalexin group and 102 in the cefazolin and probenecid group. The proportion of patients failing therapy at 72 hours was similar between the treatment groups (4.2% and 6.1%, risk difference 1.9%, 95% CI -3.7% to 7.6%). Clinical cure at 7 days was not significantly different (100% and 97.7%, risk difference -2.3%, 95% CI -6.7% to 0.8%).

CONCLUSION

Cephalexin at appropriate doses appears to be a safe and effective alternative to outpatient parenteral cefazolin in the treatment of uncomplicated mild-moderate SSTIs who present to the ED.

TRIAL REGISTRATION NUMBER

NCT01029782; Results.

Evaluating an admission avoidance pathway for children in the emergency department: outpatient intravenous antibiotics for moderate/severe cellulitis

OBJECTIVE

Children with moderate/severe cellulitis requiring intravenous antibiotics are usually admitted to hospital. Admission avoidance is attractive but there are few data in children. We implemented a new pathway for children to be treated with intravenous antibiotics at home and aimed to describe the characteristics of patients treated on this pathway and in hospital and to evaluate the outcomes.

METHODS

This is a prospective, observational cohort study of children aged 6 months-18 years attending the ED with uncomplicated moderate/severe cellulitis in March 2014-January 2015. Patients received either intravenous ceftriaxone at home or intravenous flucloxacillin in hospital based on physician discretion. Primary outcome was treatment failure defined as antibiotic change within 48 hours due to inadequate clinical improvement or serious adverse events. Secondary outcomes include duration of intravenous antibiotics and complications.

RESULTS

115 children were included: 47 (41%) in the home group and 68 (59%) in the hospital group (59 hospital-only, 9 transferred home during treatment). The groups had similar clinical features. 2/47 (4%) of the children in the home group compared with 8/59 (14%) in the hospital group had treatment failure (P=0.10). Duration of intravenous antibiotics (median 1.9 vs 1.8 days, P=0.31) and complications (6% vs 10%, P=0.49) were no different between groups. Home treatment costs less, averaging $A1166 (£705) per episode compared with $A2594 (£1570) in hospital.

CONCLUSIONS

Children with uncomplicated cellulitis may be able to avoid hospital admission via a home intravenous pathway. This approach has the potential to provide cost and other benefits of home treatment.

Meta-analysis of randomised trials comparing a penicillin or cephalosporin with a macrolide or lincosamide in the treatment of cellulitis or erysipelas

PURPOSE

Beta-lactam antibiotics, such as penicillin, flucloxacillin or cephalexin, are widely considered first-line treatment for cellulitis and erysipelas, while macrolides and lincosamides, such as erythromycin, azithromycin or clindamycin, are widely considered second-line agents. We attempted to determine whether outcomes differed between patients treated either with a beta-lactam or with a macrolide or lincosamide.

METHODS

We conducted a meta-analysis of published trials in which patients with cellulitis or erysipelas were randomised to treatment either with a beta-lactam or with a macrolide or lincosamide. We searched PUBMED, EMBASE, MEDLINE and SCOPUS (up to March 2014) using the terms: cellulitis/erysipelas, penicillin/beta-lactam, macrolide/lincosamide, random*/controlled*/trial* as keywords. We included randomised trials that compared monotherapy with a beta-lactam with monotherapy with a macrolide or lincosamide for cellulitis or erysipelas.

RESULTS

We identified 15 studies, 9 in patients with cellulitis or erysipelas and 6 in patients with various skin and soft tissue infections including cellulitis and erysipelas. The efficacy of treatment of cellulitis or erysipelas was similar with a beta-lactam [27/221 (12 %) not cured] and a macrolide or lincosamide [21/241 (9 %) not cured, RR 1.24, 95 % CI 0.72-2.41, p = 0.44]. Treatment efficacy was also similar for skin or soft tissue infections including cellulitis and erysipelas (RR 1.28, 95 % CI 0.96-1.69, p = 0.09). Risk of adverse effects was similar for beta-lactams [148/1295 (11 %) not cured] and macrolides or lincosamides [228/1737 (13 %) not cured, RR 0.86, 95 % CI 0.64-1.16, p = 0.31].

CONCLUSION

Treatment with a macrolide or lincosamide for cellulitis or erysipelas has a similar efficacy and incidence of adverse effects as treatment with a beta-lactam.

Who Can Have Parenteral Antibiotics at Home?: A Prospective Observational Study in Children with Moderate/Severe Cellulitis

BACKGROUND

The benefits of treating children at home or in an ambulatory setting have been well documented. We aimed to describe the characteristics and evaluate the outcomes of children with moderate/severe cellulitis treated at home with intravenous (IV) ceftriaxone via direct referral from the Emergency Department to a hospital-in-the-home (HITH) program.

METHODS

Patients aged 3 months to 18 years with moderate/severe cellulitis referred from a tertiary pediatric Emergency Department to HITH from September 2012 to January 2014 were prospectively identified. Data collection included demographics, clinical features, microbiological characteristics and outcomes. To ensure home treatment did not result in inferior outcomes, these patients were retrospectively compared with patients who were hospitalized for IV flucloxacillin, the standard-of-care over the same period. The primary outcome was home treatment failure necessitating hospital admission. Secondary outcomes included antibiotic changes, complications, length of stay and cost.

RESULTS

Forty-one (28%) patients were treated on HITH and 103 (72%) were hospitalized. Compared with hospitalized patients, HITH patients were older (P < 0.01) and less likely to have periorbital cellulitis (P = 0.01) or fever (P = 0.04). There were no treatment failures under HITH care. The rate of antibiotic changes was similar in both groups (5% vs. 7%, P = 0.67), as was IV antibiotic duration (2.3 vs. 2.5 days, P = 0.23).

CONCLUSION

Older children with moderate/severe limb cellulitis without systemic symptoms can be treated at home. To ascertain if this practice can be applied more widely, a comparative prospective, ideally randomized, study is needed.

Treatment failure in emergency department patients with cellulitis

Objective:

To identify the rate of treatment failure in emergency department patients with cellulitis.

Methods:

This prospective observational convenience study enrolled adult patients with uncomplicated cellulitis. Physicians performed a standardized assessment prior to treatment. To calculate the interrater reliability of the assessment, duplicate data collection forms were completed on a small subsample of patients. Treatment failure was defined as the occurrence of any one of the following events after the initial emergency department visit: incision and drainage of abscess; change in antibiotics (not due to allergy/intolerance); specialist consultation; or, hospital admission. Comparison of means and proportions between the 2 groups was performed with univariate associations, using parametric or non-parametric tests where appropriate.

Results:

Seventy-five patients were enrolled; 57% were male, the mean age was 48 (standard deviation 19), 71 (95%) patients had extremity cellulitis and 10 (13%) had abscess with cellulitis. Fourteen episodes (18.7%, 95% confidence interval [CI] 11%–28%) were classified as treatment failures, with an oral antibiotic failure rate of 6.8% (95% CI 2%–22%) and an emergency department-based intravenous antibiotic failure rate of 26.1% (95% CI 16%–40%). Patients with treatment failure were older (mean age 59 yr v. 46 yr,p= 0.02) and more likely to have been taking oral antibiotics at enrolment (50% v. 16.4%,p= 0.01). Patients with a larger surface area of infection were also more likely to fail treatment (465.1 cm2v. 101.5 cm2,p&lt; 0.01). Interrater agreement was high for the presence of fever (kappa 1.0) and the size of surface area of infection (intraclass correlation coefficient 0.98), but low for assessments of both severity (kappa 0.35) and need for admission (kappa 0.46).

Conclusions:

The treatment of cellulitis with daily emergency department–based intravenous antibiotics has a failure rate of more than 25% in our centre. Cellulitis patients with a larger surface area of infection and previous (failed) oral therapy are more likely to fail treatment. Further research should focus on defining eligibility for treatment with emergency department-based intravenous antibiotics.

Oral versus parenteral antimicrobials for the treatment of cellulitis: a randomized non-inferiority trial

OBJECTIVES

To determine whether outcomes for patients with cellulitis treated with oral antimicrobials are as good as for those who are treated with parenteral antimicrobials.

METHODS

A prospective randomized non-inferiority trial was conducted at a tertiary teaching hospital in Melbourne, Australia. Participants were patients referred by the emergency department for treatment of uncomplicated cellulitis with parenteral antimicrobials. Patients were randomized to receive either oral cefalexin or parenteral cefazolin. Parenteral antimicrobials were changed to oral after the area of cellulitis ceased progressing. The primary outcome was days until no advancement of the area of cellulitis. A non-inferiority margin of 15% was set for the oral arm compared with the parenteral arm. Secondary outcomes were failure of treatment, pain, complications and satisfaction with care. This trial is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12611000685910).

RESULTS

Twenty-four patients were randomized to oral antimicrobials and 23 to parenteral antimicrobials. Mean days to no advancement of cellulitis was 1.29 (SD 0.62) for the oral arm and 1.78 (SD 1.13) for the parenteral arm, with a mean difference of -0.49 (95% CI: -1.02 to +0.04). The upper limit of the 95% CI of the difference in means of +0.04 was below the 15% non-inferiority margin of +0.27 days, indicating non-inferiority. More patients failed treatment in the parenteral arm (5 of 23, 22%) compared with the oral arm (1 of 24, 4%), although this difference was not statistically significant (P=0.10). Pain, complications and satisfaction with care were similar for both groups.

CONCLUSIONS

Oral antimicrobials are as effective as parenteral antimicrobials for the treatment of uncomplicated cellulitis.

Photodocumentation as an emergency department documentation tool in soft tissue infection: a randomized trial

OBJECTIVES

Current documentation methods for patients with skin and soft tissue infections receiving outpatient parenteral anti-infective therapy (OPAT) include written descriptions and drawings of the infection that may inadequately communicate clinical status. We undertook a study to determine whether photodocumentation (PD) improves the duration of outpatient treatment of skin and soft tissue infections.

METHODS

A single-blinded, prospective, randomized trial was conducted in the emergency departments of a community hospital and an academic tertiary centre. Participants included consecutive patients age ≥ 14 years presenting with noninvasive skin and soft tissue infections requiring OPAT. Patients in the intervention arm were treated with standard of care plus PD at each emergency physician assessment. Control subjects received care provided at the discretion of the treating physician and non-photographic documentation. The primary outcome was duration of therapy measured in half-days. The required sample size to detect a difference of one half-day was 253 patients per group (α  =  0.05). Secondary outcomes included (1) completion and therapeutic failure rates, (2) patient satisfaction, and (3) physician and nurse satisfaction.

RESULTS

Enrolment was slower and follow-up rates lower than anticipated, and the trial was terminated when funds were exhausted. A total of 468 subjects with similar age and gender characteristics were enrolled, with 244 receiving the intervention and 224 in the control arm. The mean OPAT duration was similar in the two groups (3.6 days v. 3.5 days, p  =  0.73). No differences in the rate for completion and therapeutic failure were observed (71% v. 68% and < 1% for both, respectively). Survey response rates varied significantly: patients, 65%; nurses, 17%; and physicians, 87%. Physicians endorsed more comfort with their assessment and OPAT judgment with PD (65% and 64%, respectively). Physicians cited too much time lost with technological challenges, which would affect implementation in a busy ED.

CONCLUSIONS

PD as an intervention is acceptable to patients and has reasonable endorsement by the majority of physicians. This trial had significant limitations that threatened the integrity of the study, so the results are inconclusive.

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.

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.

[Summary of the GEIPC-SEIMC and GTEI-SEMICYUC recommendations for the treatment of infections caused by gram positive cocci in critical patients]

OBJECTIVE

In recent years there has been an increase in infections caused by gram-positive cocci in critical patients, together with a rapid development of resistance to the antibiotics which are normally used to treat them. The objective is to prepare an antibiotic treatment guide for the most common infections caused by gram positive cocci in critical patients. This guide will help in the decision-making process regarding the care of such patients.

METHOD

Experts from two scientific societies worked together to prepare a consensus document. They were members of the Study Group on Infections in Critical Patients (GEIPC), which is part of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC), and the Infectious Diseases Working Group (GTEI), belonging to the Spanish Society of Intensive Care Medicine and Coronary Units (SEMICYUC). There was a systematic review of the literature published up to September 2006 regarding this type of infections and the antibiotic treatments marketed to that date. An evidence grading system was applied according to the strength of the recommendation (categories A, B or C) and the level of evidence (categories I, II or III). Recommendations were given if there was consensus among the experts from both societies.

RESULTS

The antibiotic regimens recommended for treating infections caused by gram-positive cocci were presented in the form of tables, showing the recommendation grade. Alternatives were given for allergic patients. The scientific basis supporting the aforementioned recommendations is explained within the text and the references upon which they are based are cited.

CONCLUSIONS

A summary of an evidence-based practical guide for the treatment of infections caused by gram-positive cocci in critical patients is presented.

[GEIPC-SEIMC (Study Group for Infections in the Critically Ill Patient of the Spanish Society for Infectious Diseases and Clinical Microbiology) and GTEI-SEMICYUC ( Working Group on Infectious Diseases of the Spanish Society of Intensive Medicine, Critical Care, and Coronary Units) recommendations for antibiotic treatment of gram-positive cocci infections in the critical patient]

In recent years, an increment of infections caused by gram-positive cocci has been documented in nosocomial and hospital-acquired-infections. In diverse countries, a rapid development of resistance to common antibiotics against gram-positive cocci has been observed. This situation is exceptional in Spain but our country might be affected in the near future. New antimicrobials active against these multi-drug resistant pathogens are nowadays available. It is essential to improve our current knowledge about pharmacokinetic properties of traditional and new antimicrobials to maximize its effectiveness and to minimize toxicity. These issues are even more important in critically ill patients because inadequate empirical therapy is associated with therapeutic failure and a poor outcome. Experts representing two scientific societies (Grupo de estudio de Infecciones en el Paciente Crítico de la SEIMC and Grupo de trabajo de Enfermedades Infecciosas de la SEMICYUC) have elaborated a consensus document based on the current scientific evidence to summarize recommendations for the treatment of serious infections caused by gram-positive cocci in critically ill patients.

Management of cellulitis in a pediatric emergency department

OBJECTIVES

(1) To determine antibiotic choices, route of administration, and outcomes of children treated as outpatients with noncomplicated, nonfacial cellulitis at a tertiary care center. (2) To determine the number of visits and time spent in the emergency department (ED) for treatment.

DESIGN

A descriptive case-control study.

SETTING

A tertiary care pediatric ED at an academic medical center.

METHODS

Medical records of all otherwise healthy children (aged 1-16 yrs) presenting with noncomplicated, nonfacial cellulitis over a 3-year period (January 1, 2001-December 31, 2003) were reviewed. Data extracted included the following: demographics; clinical presentation; laboratory and microbiology results; management, including choice, dose, and route of antibiotic(s); treatment failures; and time spent in the ED.

INTERVENTIONS

None.

MAIN RESULTS

Two hundred sixty-nine patients met the inclusion criteria, and their charts were selected for review. The oral antibiotic most often prescribed was cephalexin (N = 105). Treatment failure occurred in 10 (8.9%) of the cases. The intravenous antibiotic most often prescribed was cefazolin (N = 124; 39 received cefazolin alone, and 85 received cefazolin and probenecid). The cefazolin-only group had 12 (31%) treatment failures, whereas the cefazolin and probenecid group had 7 (8.1%) treatment failures. More time in the ED (521 +/- 287 minutes) and more visits (3.4 +/- 2.8) were seen in the intravenous group as compared with the oral group (time in ED, 164 +/- 139 minutes; visits, 1.4 +/- 1).

CONCLUSIONS

Noncomplicated, nonfacial cellulitis is most commonly treated using first-generation cephalosporins. Treatment with oral antibiotics was effective and required fewer visits and less time in the ED compared with intravenous treatment. Twice-daily cefazolin and probenecid was associated with less treatment failures and admissions than cefazolin alone and may represent a reasonable alternative for children with nonfacial cellulitis requiring intravenous antibiotics.

Recomendaciones GEIPC-SEIMC y GTEI-SEMICYUC para el tratamiento antibiótico de infecciones por cocos grampositivos en el paciente crítico

In recent years, an increment of infections caused by gram-positive cocci has been documented in nosocomial and hospital-acquired infections. In diverse countries, a rapid development of resistance to common antibiotics against gram-positive cocci has been observed. This situation is exceptional in Spain but our country might be affected in the near future. New antimicrobials active against these multi-drug resistant pathogens are nowadays available. It is essential to improve our current knowledge about pharmacokinetic properties of traditional and new antimicrobials to maximize its effectiveness and to minimize toxicity. These issues are even more important in critically ill patients because inadequate empirical therapy is associated with therapeutic failure and a poor outcome. Experts representing two scientific societies (Grupo de estudio de Infecciones en el Paciente Critico de la SEIMC and Grupo de trabajo de Enfermedades Infecciosas de la SEMICYUC) have elaborated a consensus document based on the current scientific evidence to summarize recommendations for the treatment of serious infections caused by gram-positive cocci in critically ill patients.

Acute bacterial skin infections and cellulitis

PURPOSE OF REVIEW

Acute bacterial skin infections are very common, with various presentations and severity. This review focuses on deep skin infections. We separate acute nonnecrotizing infections of the hypodermis (erysipelas), forms with abscesses or exudates and necrotizing fasciitis. These three types actually differ in risk factors, bacteriology, treatment and prognosis.

RECENT FINDINGS

Leg erysipelas/cellulitis occurs in more than one person/1000/year. It remains mainly due to streptococci. Foot intertrigo is an important risk factor. Necrotizing fasciitis is much rarer and usually occurs in patients with chronic diseases. Staphylococci, especially community-acquired methicillin-resistant strains in some areas, play a growing role in the intermediate form of cellulitis with abscesses and exudates. For erysipelas or noncomplicated cellulitis, antibiotic treatment at home, when feasible, is much less expensive and as effective as hospital treatment. Intermediate cases with collections and exudates often require surgical drainage. For necrotizing fasciitis early surgery remains essential in order to decrease the mortality rate.

SUMMARY

Antibiotic treatment of deep skin infections must be active on streptococci; the choice of a larger spectrum of activity depends on clinical presentation, risk factors and the burden of methicillin-resistant staphylococci in the environment.

Treatment ofStaphylococcus aureusinfections: new issues, emerging therapies and future directions

Infections due to Staphylococcus aureus are a major cause of morbidity and mortality worldwide. Antimicrobial resistance in strains of S. aureus is a continually evolving problem, including widespread methicillin resistance in hospitals, increasing methicillin resistance in community strains, and the recent acquisition of glycopeptide resistance. New antimicrobials with activity against S. aureus have recently entered the market or are in the late stages of development. In addition, there has been significant interest in the development of novel and immune-based strategies for prevention or treatment of S. aureus infections. This review describes established and emerging therapies for S. aureus infections, and considers the safety profiles and likely impact on present treatment standards of novel agents either undergoing clinical development or emerging onto the market.

Emergency department management of home intravenous antibiotic therapy for cellulitis

OBJECTIVES

To evaluate the safety and efficacy of using intravenous cephazolin as a first line antibiotic for the treatment of cellulitis in a supervised outpatient programme.

METHODS

This study was a retrospective analysis and included all patients who attended the emergency department (ED) of a university affiliated hospital in Sydney over the period of 1 year and who satisfied the following inclusion criteria: (a) age >16 years, (b) presented with acute cellulitis, and (c) were suitable for home intravenous antibiotic therapy according to APAC guidelines.

RESULTS

In total, 124 patients were included, of whom 53 (42.7%) presented directly to the ED and 71 (57.3%) were referred by their general practitioner. Of these 124 patients, 75 (60.5%) were men and 49 (39.5%) were women. Age range was 16-97 years. There were 82 (66.2%) presentations of cellulitis of the lower limb, 30 (24.2%) of the upper limb, 9 (7.2%) of the face and 3 (2.4%) of the torso. Cephazolin 2 g twice daily was given to 123 (99.2%) of the patients, and one patient (0.8%) received ceftriaxone 2 g once daily. In total, 105 patients (84.7%) were treated successfully and 19 (15.3%) were re-admitted. Four of the unsuccessful treatment group required incision and drainage of abscesses. The mean duration of intravenous therapy was 6.24 days. One patient developed diarrhoea. There were no other complications attributable to therapy.

CONCLUSION

Low re-admission rates verify the efficacy of cephazolin 2 g twice daily in treating cellulitis in the home environment. Benefits are multiple and include economic savings and reduced risk of nosocomial infection.

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.

Randomised controlled trial of intravenous antibiotic treatment for cellulitis at home compared with hospital

OBJECTIVES

To compare the efficacy, safety, and acceptability of treatment with intravenous antibiotics for cellulitis at home and in hospital.

DESIGN

Prospective randomised controlled trial.

SETTING

Christchurch, New Zealand.

PARTICIPANTS

200 patients presenting or referred to the only emergency department in Christchurch who were thought to require intravenous antibiotic treatment for cellulitis and who did not have any contraindications to home care were randomly assigned to receive treatment either at home or in hospital.

MAIN OUTCOME MEASURES

Days to no advancement of cellulitis was the primary outcome measure. Days on intravenous and oral antibiotics, days in hospital or in the home care programme, complications, degree of functioning and pain, and satisfaction with site of care were also recorded.

RESULTS

The two treatment groups did not differ significantly for the primary outcome of days to no advancement of cellulitis, with a mean of 1.50 days (SD 0.11) for the group receiving treatment at home and 1.49 days (SD 0.10) for the group receiving treatment in hospital (mean difference 0.01 days, 95% confidence interval -0.3 to 0.28). None of the other outcome measures differed significantly except for patients' satisfaction, which was greater in patients treated at home.

CONCLUSIONS

Treatment of cellulitis requiring intravenous antibiotics can be safely delivered at home. Patients prefer home treatment, but in this study only about one third of patients presenting at hospital for intravenous treatment of cellulitis were considered suitable for home treatment.

Once-Daily Cefazolin and Probenecid for Skin and Soft Tissue Infections

OBJECTIVE

To review the pharmacokinetic and clinical evidence for the use of once-daily cefazolin and probenecid in the treatment of skin and soft tissue infections (SSTI).

DATA SOURCES

MEDLINE (1966–July 2003), EMBASE (1980–July 2003), and PubMed (1966–July 2003) databases for English language, human reports were searched. Search terms included cefazolin, probenecid, cellulitis, and soft tissue infections.

STUDY SELECTION AND DATA EXTRACTION

Studies that described pharmacokinetic and clinical outcomes that evaluated the use of cefazolin in conjunction with probenecid for SSTI were included. All studies were evaluated independently by both authors. For pharmacokinetic studies, the effect of probenecid on the pharmacokinetics of cefazolin was evaluated. For clinical trials, efficacy and safety endpoints were evaluated. For efficacy endpoints, definition of cure was used as defined by each trial.

DATA SYNTHESIS

In all 3 pharmacokinetic studies identified, the addition of probenecid to cefazolin therapy prolonged the half-life and increased serum concentrations of cefazolin. This process allowed serum concentrations to be above the minimal inhibitory concentrations (MIC) for the most likely skin pathogens ( Staphylococcus aureus, β-hemolytic streptococci) at the end of the dosing interval. In the first of 2 clinical trials, 7 (7%) of 96 patients receiving intravenous ceftriaxone 2 g and oral probenecid 1 g daily were reported to fail therapy compared with 8 (8%) of 98 patients receiving intravenous cefazolin 2 g and oral probenecid 1 g daily. In the second clinical trial, clinical success was reported in 51 (86%) of 59 patients receiving the same doses of cefazolin and probenecid as above compared with 55 (96%) of 57 patients receiving intravenous ceftriaxone 1 g and oral placebo daily.

CONCLUSIONS

Limited pharmacokinetic and clinical data suggest that intravenous cefazolin 2 g and oral probenecid 1 g daily is an effective regimen in the treatment of SSTI.

Once-Weekly Dalbavancin versus Standard-of-Care Antimicrobial Regimens for Treatment of Skin and Soft-Tissue Infections

Dalbavancin, a novel glycopeptide with a long elimination half-life ( approximately 9-12 days), was compared to standard antimicrobial therapy for skin and soft-tissue infections (SSTIs). In a randomized, controlled, open-label, phase 2 proof-of-concept trial, adults received 1100 mg of dalbavancin (as a single intravenous infusion), 1000 mg of dalbavancin intravenously and then 500 mg intravenously 1 week later, or a prospectively defined standard-of-care regimen. A gram-positive pathogen was isolated from samples obtained from 41 (66%) of 62 patients at baseline; Staphylococcus aureus was the most prevalent species (83% of pathogens). Clinical success rates at a follow-up visit (test of cure) were 94.1% among patients treated with 2 doses of dalbavancin, 61.5% among patients treated with 1 dose of dalbavancin, and 76.2% among patients treated with a standard-of-care regimen. All treatment regimens were well tolerated; drug-related adverse reaction rates were similar across the 3 groups. These findings suggest that a regimen of 2 doses of dalbavancin administered 1 week apart is effective in the treatment of complicated, gram-positive bacterial SSTIs and warrants further study.