Quinupristin and Dalfopristin

Quinupristin and dalfopristin are streptogramin antibiotics, which, like macrolides and lincosamides, inhibit the synthesis of bacterial proteins.

Quinupristin/dalfopristin (Q/D) is given together in a fixed 30/70 combination; this combination has synergistic bactericidal activity against the following:

• Streptococci and staphylococci, including strains resistant to other antibiotic classes

• Some gram-negative anaerobic bacilli

• Clostridium perfringens

• Peptostreptococcus species

• Atypical respiratory pathogens (Mycoplasma pneumoniae, Chlamydophila pneumoniae, Legionella pneumophila)

Q/D inhibits Enterococcus faeciumEnterococcus faecalis is resistant.

Q/D is given via a central IV catheter because phlebitis frequently occurs when Q/D is given via a peripheral vein. Up to 30% of patients develop significant myalgias. Q/D may cause hyperbilirubinemia.

Dosage reduction is required for severe hepatic insufficiency but not for renal insufficiency.