RT Book, Section A1 Gruenberg, Katherine A1 Guglielmo, B. Joseph A2 Papadakis, Maxine A. A2 McPhee, Stephen J. A2 Rabow, Michael W. A2 McQuaid, Kenneth R. SR Print(0) ID 1184154284 T1 Streptogramins T2 Current Medical Diagnosis & Treatment 2022 YR 2022 FD 2022 PB McGraw-Hill Education PP New York, NY SN 9781264269389 LK accessmedicine.mhmedical.com/content.aspx?aid=1184154284 RD 2024/03/28 AB Synercid, the one approved streptogramin, is a combination of two synthetic derivatives of pristinamycin—quinupristin and dalfopristin—in a 30:70 ratio that is administered intravenously. It is bactericidal and inhibits protein synthesis by binding to bacterial ribosomes. Its major clinical use is in the therapy of gram-positive infections, particularly methicillin-resistant S aureus and S epidermidis and enterococci, including vancomycin-resistant E faecium. The combination is not reliably active against E faecalis. The recommended dose is 7.5 mg/kg/dose intravenously every 8 hours. In addition to phlebitis with peripheral administration, the major adverse effects are arthralgias and myalgias, which resolve with discontinuation of the medication. It is primarily cleared via the liver; streptogramins inhibit the cytochrome P450 system, resulting in increased levels of cyclosporine and other agents. With the availability of linezolid, daptomycin, and other agents, the indications for this agent are extremely limited.