Quinupristin and dalfopristin are lincosamide antibiotics (lincosamides, oxazolidinones and streptogramins), the semi-synthetic derivatives of pristinamycin, a naturally occurring streptogramin are. Quinupristin / dalfopristin (Q / D) is assembled, placed in a fixed 30/70 combination; this combination has a synergistic bactericidal activity against the following pathogens: streptococci and staphylococci, including strains that are resistant to other classes of antibiotics. Some Gram-negative anaerobic bacilli Clostridium perfringens Peptostreptococcus sp Atypical pathogens causing respiratory tract infections (Mycoplasma pneumoniae, Chlamydophila pneumoniae, Legionella pneumophila) Q / D inhibits Enterococcus faecium, including vancomycin-resistant strains. E. faecalis is resistant. Q / D is given intravenously over a central nervous system catheter, as it is common with peripheral venous administration of Q / D phlebitis. Up to 30% of patients develop significant myalgia. A dose reduction is required in severe hepatic impairment, but not in renal failure. Q / D can inhibit the metabolism of substances by the cytochrome P-450 (CYP450) 3A4 isoenzyme are metabolized.