Synercid
Synercid® I.V.
(quinupristin and dalfopristin) for Injection
One of Synercid's approved indications is for the treatment of patients with serious or life-threatening infections associated with vancomycin-resistant Enterococcus faecium (VREF) bacteremia. Synercid has been approved for marketing in the United States for this indication under FDA's of products for use in life-threatening conditions when other therapies are not available. Approval of drugs for marketing under these regulations is based upon a demonstrated effect on a surrogate endpoint that is likely to predict clinical benefit.
Approval of this indication is based upon Synercid's ability to clear VREF from the bloodstream, with clearance of bacteremia considered to be a surrogate endpoint. There are no results from well-controlled clinical studies that confirm the validity of this surrogate marker. However, a study to verify the clinical benefit of therapy with Synercid on traditional clinical endpoints (such as cure of the underlying infection) is presently underway.
DRUG DESCRIPTION
Synercid® (quinupristin and dalfopristin powder for injection) I.V., a streptogramin antibacterial agent for intravenous administration, is a sterile lyophilized formulation of two semisynthetic pristinamycin derivatives, quinupristin (derived from pristinamycin I) and dalfopristin (derived from pristinamycin IIA) in the ratio of 30:70 (w/w).
Quinupristin is a white to very slightly yellow, hygroscopic powder. It is a combination of three peptide macrolactones. The main component of quinupristin ( > 88.0%) has the following chemical name: N [(6R,9S,10R,13S,15aS,18R,22S,24aS)-22-[p-(dimethylamino)benzyl]-6-ethyldocosahydro-10,23-dimethyl5,8,12,15,17,21,24-heptaoxo-13-phenyl-18-[[(3S)-3-quinuclidinylthio] methyl]-12H-pyrido[2,1-]pyrrolo-[2,1 f l][1,4,7,10,13,16] oxapentaazacyclononadecin-9-yl]-3-hydroxypicolinamide.
The main component of quinupristin has an empirical formula of C53H67N9O10S, a molecular weight of 1022.24 and the following structural formula:
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Dalfopristin is a slightly yellow to yellow, hygroscopic, powder. The chemical name for dalfopristin is: (3R,4R,5E,10E,12E,14S,26R,26aS)-26-[[2-(diethylamino)ethyl]sulfonyl]-8,9,14,15,24,25,26,26a-octahydro-14hydroxy-3-isopropyl-4,12-dimethyl-3H-21,18-nitrilo-1H,22H-pyrrolo[2,1-c][1,8,4,19]-dioxadiazacyclotetracosine1,7,16,22(4H,17H)-tetrone.
Dalfopristin has an empirical formula of C34H50N4O9S, a molecular weight of 690.85 and the following structural formula:
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Generic Name: Quinupristin and Dalfopristin
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