New pharmacological treatments for methicillin-resistant Staphylococcus aureus infections.

INTRODUCTION: Despite available treatment options for methicillin-resistant Staphylococcus aureus (MRSA), the morbidity and mortality attributed to the diverse infection manifestations of this pathogen remain high. More anti-MRSA agents are needed as options for treatment of these infections. Ideally, these new agents would be rapidly bactericidal for bloodstream clearance in septic patients, have few toxicities, be active against MRSA in biofilms, be easy to administer, and have oral bioavailability. AREAS COVERED: This review focuses on MRSA agents in Phase III trials or antibiotics currently in the market, which are being studied for new indications. For each agent, the antimicrobial potency against MRSA, pharmacokinetic and pharmacodynamic considerations and approved and potential new indications are presented. The role of novel combination therapies is also introduced. EXPERT OPINION: The new lipoglycopeptides oritavancin, telavancin and dalbavancin have the potential to make a large impact on the treatment of MRSA due to unique pharmacokinetic/pharmacodynamic properties and proposed dosing regimens. Other new agents (omadacycline and tedizolid) as well as revisited older agents (fosfomycin and fusidic acid) appear promising but require further study for their potential role. Combination therapy may improve outcomes in patients with high MRSA infection burden or when patient or pathogen factors predict a worse outcome with monotherapy.