The Effect of Combination Therapy on Mortality and Adverse Events in Patients with Staphylococcus aureus Bacteraemia: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Rifampin Based Therapy for Patients With Staphylococcus aureus Native Vertebral Osteomyelitis: A Systematic Review and Meta-analysis

BACKGROUND

Native vertebral osteomyelitis (NVO) caused by Staphylococcus aureus is associated with high risk of treatment failure and increased morbidity. The role of rifampin-based therapy for the treatment of this condition is controversial. The goal of this systematic review and meta-analysis is to explore the efficacy and safety of rifampin-based therapy for the treatment of S. aureus NVO.

METHODS

We searched Cochrane, Embase, Medline, Scopus, and Web of Science databases for studies published up to May 2023, focusing on adults with NVO treated with or without rifampin-containing regimens. A random-effects model meta-analysis estimated relative risks and risk difference with 95% confidence intervals (CI).

RESULTS

Thirteen studies (2 randomized controlled trials and 11 comparative cohort studies), comprising 244 patients with S. aureus NVO who received rifampin and 435 who did not, were analyzed. Meta-analysis showed that rifampin-based regimens were associated with lower risk of clinical failure (risk difference, -14%; 95% CI, -19% to -8%; P < .001; I2 = 0%; relative risk, 0.58; 95% CI, .37-.92, P = .02, I2 = 21%). Only 1 study reported on adverse events. All studies had a high or uncertain risk of bias, and the certainty of evidence was rated as very low.

CONCLUSIONS

Adjunctive rifampin therapy might be associated with lower risk of S. aureus NVO treatment failure; however, the low certainty of evidence precludes drawing definitive conclusions that would alter clinical practice. A randomized trial is necessary to corroborate these findings.

Safety and effectiveness of fifth generation cephalosporins for the treatment of methicillin-resistant staphylococcus aureus bloodstream infections: a narrative review exploring past, present, and future

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI) is a major issue in healthcare, since it is often associated with endocarditis or deep site foci. Relevant morbidity and mortality associated with MRSA-BSIs forced the development of new antibiotic strategies; in particular, this review will focus the attention on fifth-generation cephalosporins (ceftaroline/ceftobiprole), that are the only ß-lactams active against MRSA.

AREAS COVERED

The review discusses the available randomized controlled trials and real-world observational studies conducted on safety and effectiveness of ceftaroline/ceftobiprole for the treatment of MRSA-BSIs. Finally, a proposal of MRSA-BSI treatment flowchart, based on fifth-generation cephalosporins, is described.

EXPERT OPINION

The use of anti-MRSA cephalosporins is an acceptable choice either in monotherapy or combination therapy for the treatment of MRSA-BSIs due to their relevant effectiveness and safety. Particularly, their use may be advisable in combination therapy in case of severe infections (including endocarditis or persistent bacteriemia) or in monotherapy in subjects at higher risk of drugs-induced toxicity with older regimens. On the contrary, caution should be taken in case of suspected/ascertained central nervous system infections due to inconsistent data regarding penetration of these drugs in cerebrospinal fluid and brain tissues.

The Effectiveness of Combination Therapy for Treating Methicillin-Susceptible Staphylococcus aureus Bacteremia: A Systematic Literature Review and a Meta-Analysis

Background: This meta-analysis aims to evaluate the effectiveness of combination therapy for treating MSSA bacteremia. Methods: We searched Ovid MEDLINE, EMBASE, Cochrane CENTRAL, and clinicaltrials.gov for studies including adults with MSSA bacteremia. The monotherapy group used a first-line antibiotic active against MSSA and the combination group used a first-line antibiotic plus additional antibiotic/s. The primary outcome was all-cause mortality. Secondary outcomes included persistent bacteremia, duration of bacteremia, relapse, and adverse events. Random-effects models with inverse variance weighting were used to estimate pooled risk ratios (pRR). Heterogeneity was assessed using the I² value and the Cochrane’s Q statistic. Results: A total of 12 studies (6 randomized controlled trials [RCTs]) were included. Combination therapy did not significantly reduce 30-day mortality (pRR 0.92, 95% CI, 0.70–1.20), 90-day mortality (pRR 0.89, 95% CI, 0.74–1.06), or any-time mortality (pRR 0.91, 95% CI, 0.76–1.08). Among patients with deep-seated infections, adjunctive rifampicin may reduce 90-day mortality (3 studies with moderate-high risk of bias; pRR 0.62, 95% CI, 0.42–0.92). For secondary outcomes, combination therapy decreased the risk of relapse (pRR 0.38, 95% CI, 0.22–0.66), but this benefit was not maintained when pooling RCTs (pRR 0.54, 95% CI, 0.12–2.51). Combination therapy was associated with an increased risk of adverse events (pRR 1.74, 95% CI, 1.31–2.31). Conclusions: Combination therapy not only did not decrease mortality in patients with MSSA bacteremia, but also increased the risk of adverse events. Combination therapy may reduce the risk of relapse, but additional high-quality studies are needed.

Role of dalbavancin as combination therapy: evidences from the literature and clinical scenarios

INTRODUCTION

The off-label use of dalbavancin in patients with infections other than acute bacterial skin and skin structure infections (ABSSSI) represents an interesting therapeutic option. Its use as monotherapy or in combination with other antibiotics should be better defined.

AREAS COVERED

The aim of this review is to summarize evidence about the potential role of dalbavancin in combination with other antibiotics and describe clinical scenarios in which combination regimens including dalbavancin are useful. The studies were retrieved from PubMed using different combinations of keywords ("dalbavancin", "combination", "synergy").

EXPERT OPINION

Limited data about the use of dalbavancin in monotherapy or combined with other antibiotics are available. In vitro assays showed a synergistic effect of dalbavancin when combined with beta-lactam antibiotics. The use of dalbavancin as combination therapy in patients with ABSSSI did not demonstrate a superiority compared to monotherapy. Conversely, combination regimens including dalbavancin may be useful in specific infection types, such as bone and prosthetic joint infections or subacute/chronic intravascular infections with no possibility of device removal. Potential partner drugs might be rifampin, beta-lactams, fluoroquinolones, doxycycline and trimethoprim/sulfamethoxazole. The choice of the companion drug should be tailored on in vitro results of synergistic tests, patient's profile and type of infection.