In re: Synercid

Thu Feb 8 08:34:06 EST 1996

In response to infromation on Synercid:

Synercid is an antibiotic being developed by Rhone-Poulenc, it is a 
semisynthetic, injectable form of Pristamycin (also called Virginiamycin) which 
is a combinaiton of naturally occurring Streptogramin A and Streptogramin B 
antibiotics.  Synercid is referred to in the literature as RP59500 or 
"quinupristin/dalfopristin" to reflect the fact that it is a combination.

For information Rhone-Poulenc would be a good source.  There are many papers 
published in journals on antibiotics such as Antimicrobial Agents and 
Chemotherapy.  Keep in mind that in these journals Synercid is often referred to 
the drug by its number or "proper names".

The Synercid combination is bactericidal (against fully susceptible strains) and 
it is active against many of the multiply resistant gram positive bacteria 
(MRSA, VRE, PRSP).  However there already exists resistance to Virginiamycin, 
possibly owing to the fact that it has been used in animal feed in Europe.  And 
unfortunately its activity is only O.K. as some clinicians have acheived cures 
of vancomycin resistant Enterococcus faecium (after long term therapy) while 
others have not been so fortunate.  Also, according to the literature, Synercid 
has poor activity against strains of vancomycin resistant Enterococcus faecalis.  

Hopefully, when it is introduced, it will expand the number of therapeutic 
options available to clinicians but it is far from a panacea.

Steve Projan
Wyeth-Ayerst Research

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