Quinupristin Streptogramin antibiotic Dalfopristin Streptogramin antibiotic
Pregnancy category AU: B3 B (U.S.)
Routes of administration IV
Quinupristin/dalfopristin, or quinupristin-dalfopristin, is a combination of two antibiotics used to treat infections by staphylococci and by vancomycin-resistant Enterococcus faecium.
Quinupristin and dalfopristin are streptogramin antibiotics, derived from pristinamycin.
Quinupristin is derived from pristinamycin IA; dalfopristin from pristinamycin IIA.
They are combined in a weight-to-weight ratio of 30% quinupristin to 70% dalfopristin.
Discontinued 2022, there are no other manufacturers of this medication.
Intravenous, usually 7.5 mg/kg every 8 hours (infections/life threatening VRSA); every 12 hours (skin infections).
No renal dosing adjustments, hepatic dosing adjustments are not defined, consider reducing dose.
Quinupristin and dalfopristin are protein synthesis inhibitors in a synergistic manner.
While each of the two is only a bacteriostatic agent, the combination shows bactericidal activity.
Dalfopristin enhances the binding of quinupristin by a factor of about 100. In addition, it inhibits peptidyl transfer.
Quinupristin binds to a nearby site on the 50S ribosomal subunit and prevents elongation of the polypeptide, as well as causing incomplete chains to be released.
Clearance by the liver CYP450:3A4 inhibitor, half-life quinupristin 0.8 hours, dalfopristin 0.7 hours.
Side effects:
C.diff-associated diarrhea superinfection anaphylactoid reactions angioedema
Common: Joint aches or muscle aches Nausea, diarrhea or vomiting Rash or itching Headache Hyperbilirubinemia Anemia Thrombophlebitis Drug interactions
The drug inhibits P450 and enhances the effects of terfenadine, astemizole, indinavir, midazolam, calcium channel blockers, warfarin, cisapride and ciclosporin.