Safety and efficacy of commonly used antimicrobial agents in the treatment of enterococcal infections: a review

ABSTRACT

Introduction: Enterococci have become the second leading cause of nosocomial infections in the U.S, which are associated with higher morbidity, mortality, length of stay, and cost due to escalating resistance to several antimicrobial agents. With limited treatment options, the adverse events associated with the increasing use of available agents must be considered.

Areas covered: Safety data about the most commonly used antimicrobial agents to treat enterococcal infections (ampicillin, vancomycin, linezolid, daptomycin, and tigecycline) derived from animal models, clinical trials and post-marketing surveillance are evaluated. However, most of these agents are not FDA approved and have been used for off-label indications in enterococcal infections.

Expert opinion: The commonly used antimicrobials to treat enterococcal infections have unique safety profiles and side effects but are generally safe and tolerated in the short-term based on data from clinical trials and post-marketing surveillance. However, serious long-term adverse events may occur, and antibiotic selection should be individualized and based on source of infection, duration, potential drug-related toxicity, and drug-drug interactions to minimize side-effects. Implementing standard precautions and infection control measures, minimizing unnecessary antibiotic exposure, and optimizing treatment and duration with removal of source of infection are essential to prevent the spread of resistance and improve outcomes.

KEYWORDS:

• Ampicillin
• daptomycin
• enterococcal treatment
• linezolid
• safety
• tigecycline
• vancomycin

Article highlights

• Enterococci are the second leading cause of nosocomial infections in the US and are associated with higher morbidity, mortality, length of stay, and cost due to the increasing emergence of resistance in Enterococcus species with paucity in treatment options.

• Ampicillin, vancomycin, linezolid, daptomycin, and tigecycline alone or in combination with other agents are commonly used to treat enterococcal infections. However, most of these agents are not FDA approved and have been used for off-label indications in enterococcal infections.

• Safety data are derived from animal models, clinical trials, and postmarketing surveillance, and comparative clinical trials are limited for most of these agents.

• These agents have unique safety profiles and side effects but are generally safe and tolerated in the short term.

• Antibiotic selection should be individualized and based on source of infection, duration, potential drug-related toxicity, and drug–drug interactions to minimize adverse events.

• Implementing standard precautions and infection control measures to disrupt transmission, minimizing unnecessary antibiotic exposure, and optimizing treatment and duration with removal of source of infection are essential to prevent the spread of resistance and improve outcomes.

This box summarizes key points contained in the article.

Declaration of interest

MJ Zervos discloses relationships with Cubist, Tetraphase, Pfizer, Cerexa, AstraZeneca, Forest Research Institute, Cempra and Durata. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.