Quinupristin/dalfopristin

• Quinupristin: inhibition of the early phases of bacterial protein synthesis on the bacterial ribosomes (50s subunit of the ribosomes). Quinupristine binds to the same site as macrolide antibiotics. It prevents polypeptide elongation and thus causes the inhibition of bacterial protein biosynthesis.
• Dalfopristin: inhibition of the late stages of bacterial protein synthesis on bacterial ribosomes. Dalfopristin reacts with an adjacent region of the binding site of quinupristin on the 50s subunit of the ribosome and synergistically increases the probability of binding of quinupristin at its point of action. Dalfopristine also inhibits polypeptide chain formation.

Bacteriostatic activity against Enterococcus faecium (only vancomycin-resistant and multiresistant strains). Not effective against Enterococcus faecalis. Bactericidally effective against methicillin-sensitive staphylococci, methicillin-resistant Staph. aureus), VRSA (vancomycin-resistant Staph. aureus) and VRE (vancomycin-resistant enterococci), Mycobacterium pneumoniae, Legionella spp. and Chlamydia pneumoniae.

• Approved in the USA for the treatment of severe or life-threatening infections caused by vancomycin-resistant Enterococcus faecium strains (VREF).
• Also approved for the treatment of severe skin and soft tissue infections caused by Staphylococcus aureus (methicillin-sensitive) or Streptococcus pyogenes infections.

Notice! Not yet approved in the Federal Republic of Germany.

Remember! Quinupristin/Dalfopristin can only be applied intravenously. The infusion time should not be less than one hour in order to limit local reactions at the injection site of the venous access. It can only be dissolved and infused in a 5% dextrose solution, as it interacts with sodium chloride!

1. Grossi PA (2009) Early appropriate therapy of Gram-positive bloodstream infections: the conservative use of new drugs. Int J Antimicrob Agents 34 (Suppl 4): S31-34
2. Karageorgopoulos DE, Falagas ME (2009) New antibiotics: optimal use in current clinical practice. Int J Antimicrob Agents 34 (Suppl 4): S55-62
3. Nailor MD, Sobel JD (2009) Antibiotics for gram-positive bacterial infections: vancomycin, teicoplanin, quinupristin/dalfopristin, oxazolidinones, daptomycin, dalbavancin, and telavancin. Infect Dis Clin North Am 23: 965-982
4. Wesson KM et al (2004) Linezolid, quinupristin/dalfopristin, and daptomycin in dermatology. Dis Mon 50: 395-406