Quinupristin-dalfopristin.

Quinupristin-dalfopristin (RP 59500) is an injectable streptogramin antibiotic. It possesses a wide spectrum of activity against Gram-positive bacteria including methicillin-resistant staphylococci, glycopeptide-resistant. Enterococcus faecium and penicillin-resistant pneumococci. Quinupristin-dalfopristin has activity against some anaerobes and selected Gram-negative pathogens. Quinupristin-dalfopristin, by way synergism of between its 2 components, is unaffected by most forms of bacterial resistance. Rare forms of macrolide-lincosamide-streptogramin group B resistance may affect its activity; however, at present the incidence of strains with this type of resistance remains low. Quinupristin-dalfopristin is bactericidal against streptococci and staphylococci but has weak or no bactericidal activity against enterococci. In a compassionate use programme, 67% of 95 evaluable patients with vancomycin-resistant Gram-positive infections or intolerant of vancomycin showed improvement with eradication of infection.