WITH THE continuing development of clinical drug resistance among bacteria and the advent of resistance to the more recently released agents quinupristin/dalfopristin and linezolid, the need for new, effective agents to treat multidrug-resistant gram-positive infections remains important. With treatment options limited, it has become critical to identify antibiotics with novel mechanisms of activity. Several new drugs have emerged as possible therapeutic alternatives. This chapter focuses on agents newly introduced and those currently in clinical development for the treatment of skin and skin structure infections. In addition, novel antifungal agents will be reviewed, as will novel dosing of antiviral agents for herpes labialis.
NOVEL ANTIBACTERIAL AGENTS
There has been an alarming increase in the incidence of gram-positive infections, including resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) and drug-resistant pneumococci. Although vancomycin has been considered the drug of last defense against gram-positive multidrug-resistant bacteria, strains of vancomycin-resistant bacteria, including vancomycin-resistant enterococci (VRE), began to emerge by the late 1980s. More recently, strains of vancomycin-intermediate-resistant S. aureus (VISA) have been isolated.
Gram-positive bacteria, such as S. aureus and Streptococcus pyogenes, are often the cause of both uncomplicated and complicated skin and skin structure infections. Uncomplicated infections are mild, localized to the skin, and responsive to topical or systemic antibiotics. This category includes simple abscesses, impetiginized lesions, furuncles, and cellulitis. Complicated infections are those involving deeper soft tissues and requiring surgical intervention or associated with significant systemic disease or comorbidities.