Quinupristin-Dalfopristin Complex (mesylate) (Synonyms: RP 59500)

Quinupristin-Dalfopristin Complex is a mixture of two streptrogramin antibiotics.

Quinupristin-dalfopristin complex is a mixture of two streptrogramin antibiotics, dalfopristin and quinupristin. Streptogramin antibiotics are divided into types A and B, which in combination can act synergistically.

In vitro: A previous study compared the molecular interactions of the streptogramin combinations Synercid (type A, dalfopristin; type B, quinupristin) and NXL 103 (type A, flopristin; type B, linopristin) with the Escherichia coli 70S ribosome. Results showed that the streptogramin A and B components in Synercid and NXL 103 exhibited synergistic antimicrobial activity against certain pathogenic bacteria. Moreover, in transcription-coupled translation assays, only combinations including dalfopristin, the streptogramin A component of Synercid, showed synergy [1].

In vivo: A previous animal study aimed to investigate the efficacy of quinupristin/dalfopristin in the prevention of prosthetic graft infection in a rat subcutaneous pouch model. Results showd that quinupristin/dalfopristin had a significantly higher efficacy than levofloxacin and doxycycline. In addition, only the group treated with quinupristin/dalfopristin combined with levofloxacin or doxycycline showed no evidence of staphylococcal infection [2].

Clinical trial: In a randomized multicentric trial comparing Synercid with vancomycin for the treatment of nosocomial pneumonia due to gram-positive cocci, the cure rate (56.3% vs 58.3%) were equivalent in the 2 treatment arms. Treatment failures were also similar: 44% vs 42%. Mortality (25% vs 22%) was likewise comparable, as was tolerance [3].

References:
[1] Noeske, J. ,Huang, J.,Olivier, N.B., et al. Synergy of streptogramin antibiotics occurs independently of their effects on translation. Antimicrobial Agents and Chemotherapy 58(9), 5269-5279 (2014).
[2] Ghiselli R, Giacometti A, Cirioni O, Mocchegiani F, Orlando F, Del Prete M, D'Amato G, Scalise G, Saba V.  Quinupristin/dalfopristin bonding in combination with intraperitoneal antibiotics prevent infection of knitted polyester graft material in a subcutaneous rat pouch model infected with resistant Staphylococcus epidermidis. Eur J Vasc Endovasc Surg. 2002 Sep;24(3):230-4.
[3] Potel G.  Value of Synercid in clinical practice: from temporary approval to clinical trial authorization. Presse Med. 2001 Sep 8;30(25 Pt 2):XIX-XXII.