Information about Quinupristin-dalfopristin
Quinupristin and dalfopristin are intravenously administered, streptogramin antibiotics used in fixed combination to treat severe bacterial infections due to susceptible organisms including methicillin resistant Staphylococcus aureus (MRSA).
Liver safety of Quinupristin-dalfopristin
The fixed combination of quinupristin and dalfopristin is associated with a low rate of serum enzyme elevations during therapy but has not been convincingly linked to instances of clinically apparent liver injury.
Mechanism of action of Quinupristin-dalfopristin
Quinupristin (kwin" ue pris' tin) and dalfopristin (dal” foe pris’ tin) are streptogramin antibiotics that were initially isolated from Streptomyces pristinaspiralis. Quinupristin, a derivative of pristamycin IA, and dalfopristin, a derivative of pristamycin IIA, are synergistic in activity and are used in a fixed dose combination in a ratio of 30:70 by weight. This combination binds and inhibits the activity of the 50S subunit of bacterial ribosomes, which yields potent bactericidal activity against many gram positive bacteria including methicillin resistant forms of Staphylococcus aureus (MRSA). Quinupristin and dalfopristin also have activity against some gram negative bacteria including Enterococcus species.
FDA approval information for Quinupristin-dalfopristin
The combination of quinupristin and dalfopristin under the brand same of Synercid was approved for use in the United States in 1999. Current indications include complicated skin and skin structure infections caused by susceptible strains of Staphylococcus aureus or Streptococcus pyogenes and severe infections due to susceptible vancomycin-resistant Enterococcus faecium.
Dosage and administration for Quinupristin-dalfopristin
The combination of quinupristin and dalfopristin is available in solution in 10 mL vials of 500 mg (150 mg of quinupristin and 350 mg of dalfopristin) and the typical dose regimen is 7.5 mg/kg intravenously every 8 to 12 hours for 5 to 14 days.
Side effects of Quinupristin-dalfopristin
Side effects may include nausea, diarrhea, headache, skin rash, myalgia, arthralgia and injection site reactions (burning, irritation, pain). Rare, but potentially severe side effects include anaphylaxis and angioneurotic edema.