Moxalactam vs tobramycin-clindamycin. A randomized trial in secondary peritonitis

Current indications for the use of clindamycin: A critical review

OBJECTIVES

To review the literature and develop evidence-based guidelines for the use of the antibiotic clindamycin.

DATA SOURCES

A search of the MEDLINE database for randomized clinical trials, cohort studies and review articles that examine the therapeutic use or potential adverse effects of clindamycin was undertaken for the years 1966 to 1996. In addition, relevant citations obtained from the references cited in the identified reviews, book chapters and antibiotic guidelines were included.

DATA EXTRACTION

Selected articles examining the indications for or adverse effects from the prophylactic or therapeutic use of clindamycin were selected. A level of evidence was assigned to the indication according to published criteria.

DATA SYNTHESIS AND CONCLUSIONS

Randomized clinical trials (level 1 evidence) support the use of clindamycin in a number of common conditions, including preoperative prophylaxis, intra-abdominal infections, recurrent group A streptococcal pharyngitis, Chlamydia trachomatis cervicitis and anaerobic lung infections. Cohort studies (level 2 evidence) support the use of clindamycin for bone and soft tissue infections. Expert opinion (level 3 evidence) supports the use of clindamycin for invasive group A streptococcal infection and the treatment of diabetic foot infections. Clindamycin's disadvantages are its high cost, the common occurrence of rash and the predisposition of patients taking clindamycin to Clostridium difficile-associated colitis. Based on cohort studies, the risk of severe diarrhea in out-patients is as low as one per 1000, but the risk of in-patients acquiring C difficile colonization may be as high as 30%.

Meta-analysis: randomized controlled trials of clindamycin/aminoglycoside vs. beta-lactam monotherapy for the treatment of intra-abdominal infections

AIM

To compare the effectiveness and safety of clindamycin/aminoglycoside with broad-spectrum beta-lactam monotherapy in patients with intra-abdominal infections by performing a meta-analysis of randomized controlled trials (RCTs).

METHODS

The relevant 28 RCTS were retrieved from PubMed searches and reviewed by two reviewers independently.

RESULTS

beta-lactam monotherapy was more effective regarding cure of the infection than clindamycin/aminoglycoside (3177 clinically evaluable patients, fixed effects model, OR = 0.67, 95% CI: 0.55-0.81). The same result was found in several subset analyses. There was no difference in all-cause mortality and attributable-to-infection mortality [2382 intention-to-treat (ITT) patients, fixed effects model, OR = 1.25, 95% CI: 0.74-2.11 and 1976 ITT patients, OR = 1.19, 95% CI: 0.59-2.41, respectively]. There was no difference regarding overall adverse events and ototoxicity (1460 ITT patients, OR = 1.05, 95% CI: 0.80-1.37, and 1404 ITT patients, OR = 3.22, 95% CI: 0.72-14.45, respectively). However, treatment with clindamycin/aminoglycoside was more likely to be associated with nephrotoxicity compared to beta-lactam (3065 ITT patients, OR = 3.7, 95% CI: 2.09-6.57). Clindamycin/aminoglycoside was less likely to be associated with antibiotic-associated diarrhoea compared to beta-lactam (3050 ITT patients, OR = 0.68, 95% CI: 0.46-1.00).

CONCLUSION

The results of our meta-analysis suggest that beta-lactams are more effective in the treatment of intra-abdominal infections compared with clindamycin/aminoglycoside.

Decision-Making Analysis for Selection of Antibiotic Treatment in Intra-Abdominal Infection Using Preference Measurements

BACKGROUND

Antimicrobial therapy of abdominal infections is important to the prognosis of affected patients. The choice of antimicrobial therapy must consider effectiveness, safety, cost, and antibiotic resistance, among numerous factors. However, in reality, decisions are made assuming bioequivalence between regimens, without considering the specific attributes of any particular regimen. The objective was to determine the best antibiotic regimen for patients with community-acquired abdominal infection on the basis of a decision analysis that included effectiveness as well as safety, measured as adverse effects.

METHODS

A decision tree was built using information from a systematic review of the literature on the effectiveness of antimicrobial regimens tested in randomized clinical trials (RCTs) and the frequency and severity of adverse effects. The quality of the articles was assessed with the Oxford criteria for RCTs. The main outcome was preferences reported by surgeons, measured on a numeric scale. Preferences were obtained using a standard survey that reported each adverse effect with its respective intensity, reversibility, sequelae, duration of symptoms, and necessity for change of antibiotic. Each of the surgeons had to assign a value blindly from 0 to 10, where 10 was the most severe. A sensitivity analysis was conducted varying the frequency of adverse effects.

RESULTS

The regimens analyzed were amikacin-metronidazole, amikacin-clindamycin, ciprofloxacin-metronidazole, ampicillin-sulbactam, ceftriaxone-metronidazole, piperacillin-tazobactam, and ertapenem. The perceived severity of adverse effects reported were: Acute neuromuscular blockade (8.0), severe allergic reaction (7.5), ototoxicity (7.4), nephrotoxicity (7.1), antibiotic-associated colitis (7.0), peripheral neuropathy (5.3), general neurological symptoms (4.9), gastrointestinal symptoms (3.1), and other general symptoms (2.6). Favored regimens were ceftriaxone-metronidazole (1.15), ampicillin-sulbactam (1.24), piperacillin-tazobactam (1.27) and ertapenem (1.28). These strategies dominated the other therapeutic schemes. Sensitivity analysis showed no changes in the dominance reported when the frequency of adverse effects was maintained in the known clinical range.

CONCLUSIONS

Antibiotic regimens that contain aminoglycosides are not bioequivalent to those without aminoglycosides when effectiveness and adverse effects are considered simultaneously. Antibiotic regimens that do not use aminoglycosides must be the first line of treatment for abdominal sepsis acquired in the community.

Antibiotic regimens for secondary peritonitis of gastrointestinal origin in adults

BACKGROUND

Secondary peritonitis is associated with a high mortality rate and if not treated successfully leads to development of abscesses, severe sepsis and multi-organ failure. Source control and adjunctive antibiotics are the mainstay of treatment. However, no conclusive evidence suggest that one antibiotic regimen is better than any other but at the same time have a lower toxicity.

OBJECTIVES

To ascertain the efficacy and adverse effects of different antibiotic regimens in treating intra-abdominal infections in adults. Outcomes were divided into primary (clinical success and effectiveness in reducing mortality) and secondary (microbiological success, preventing wound infection, intra-abdominal abscess, clinical sepsis, remote infection, superinfection, adverse reactions, duration of treatment required, effectiveness in reducing hospitalised stay, and time to defervescence).

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library, Issue 4, 2004), MEDLINE (from 1966 to November 2004), EMBASE (from 1980 to November 2004) and Cochrane Colorectal Cancer Group specialised register SR-COLOCA. Bibliographies of identified studies were screened for further relevant trials.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing different antibiotic regimens in the treatment of secondary peritonitis in adults were selected. Trials reporting gynaecological or traumatic peritonitis were excluded from this review. Ambiguity regarding suitability of trials were discussed among the review team.

DATA COLLECTION AND ANALYSIS

Six reviewers independently assessed trial quality and extracted data. Data collection was standardised using data collection form to ensure uniformity among reviewers. Statistical analyses were performed using the random effects model and the results expressed as odds ratio for dichotomous outcomes, or weight mean difference for continuous data with 95% confidence intervals.

MAIN RESULTS

Fourty studies with 5094 patients met the inclusion criteria. Sixteen different comparative antibiotic regimens were reported. All antibiotics showed equivocal comparability in terms of clinical success. Mortality did not differ between the regimens. Despite the potential high toxicity profile of regimens using aminoglycosides, this was not demonstrated in this review. The reason for this could be the inherent bias within clinical trials in the form of patient selection and stringency in monitoring drug levels.

AUTHORS' CONCLUSIONS

No specific recommendations can be made for the first line treatment of secondary peritonitis in adults with antibiotics, as all regimens showed equivocal efficacy. Other factors such as local guidelines and preferences, ease of administration, costs and availability must therefore be taken into consideration in deciding the antibiotic regimen of choice. Future trials should attempt to stratify patients and perform intention-to-treat analysis to allow better external validity.

Aminoglycosides for intra-abdominal infection: equal to the challenge?

BACKGROUND

Aminoglycosides, combined with antianaerobic agents, have been used widely for the treatment of intra-abdominal infection. However, some prospective randomized controlled trials and other data suggested that aminoglycosides were less efficacious than newer comparators for the treatment of these infections. We therefore performed a meta-analysis of all prospective randomized controlled trials utilizing aminoglycosides to reevaluate the efficacy of these agents for the treatment of intra-abdominal infection.

METHODS

Published English-language prospective randomized controlled trials comparing aminoglycosides with other agents for treatment of intra-abdominal infection were identified by MEDLINE search. For each study, data were collected regarding the number of patients enrolled and evaluated, their basic demographic characteristics, the sources of the intra-abdominal infections, the number of failures as determined by the study investigators, quality score, and the use of serum drug concentrations to monitor aminoglycoside therapy. These data were combined to calculate odds ratios for risk of therapeutic failure, which were assessed for significance using Chi-square analysis.

RESULTS

Forty-seven prospective randomized controlled trials comparing aminoglycosides to other agents were identified. These were published between 1981 and 2000, and included a total of 5,182 evaluable patients. Analysis of all studies combined revealed an odds ratio that slightly, but significantly, favored the comparators. After excluding six trials using comparators that lacked accepted antianaerobic efficacy, the odds ratio more strongly favored comparators. Trials published since 1990 also notably favored comparators. Analyzing results by quality score or the use of aminoglycoside monitoring did not alter these findings.

CONCLUSIONS

In this meta-analysis, aminoglycosides were less efficacious than newer comparators for the treatment of intra-abdominal infection. Given the well-known toxicities of these agents, we conclude that they should not be used as first-line therapy for these infections.

Early bacterial and inflammatory responses to antibiotic therapy in a model of polymicrobial peritonitis in rats

OBJECTIVE: To assess the consequences of different more or less selective treatments on the microbiological and inflammatory responses within the peritoneum. METHODS: The early effects of various antibiotic regimens were evaluated in a model of polymicrobial peritonitis with specifically prepared organisms. Six regimens (amoxycillin plus gentamicin, pefloxacin, ornidazole, pefloxacin plus ornidazole, imipenem and imipenem plus gentamicin) were evaluated at 24 h and 3 days in a non-fatal model of peritonitis in rats achieved by implantation of a capsule containing Escherichia coli, Bacteroides fragilis and Enterococcus faecalis. RESULTS: Therapies that disregarded several organisms were associated with persistence of the strains and an increased peritoneal inflammatory response within the peritoneum. In contrast, therapies active against Enterobacteriaceae and anaerobes were associated with decreases of all the inoculated organisms and a smaller inflammatory response. CONCLUSION: Therapies that disregarded the microorganisms implicated in peritoneal infection are associated with delayed bacterial eradication. The persistence of these organisms within the peritoneal fluid might be involved in prolonged peritoneal inflammation. Although it disregards enterococci, the standard therapy, represented by therapy against Enterobacteriaceae and anaerobes, demonstrates satisfactory effects towards all the inoculated organisms. This apparent contradiction could be related to mechanisms of bacterial synergy.