Quinupristin/Dalfopristin

Abstract

Quinupristin/dalfopristin, the first parenteral streptogramin, offers a unique spectrum of activity against multidrug-resistant gram-positive bacteria. In serious gram-positive infections for which there are other treatment options available, the spectrum of activity and efficacy of quinupristin/ dalfopristin should be weighed against its tolerability and drug interaction profile. However, in VREF or unresponsive MRSA infections, where few proven treatment options exist, quinupristin/dalfopristin should be considered as a treatment of choice for these seriously ill patients.

Antibiotics and the Inhibition of Ribosome Function

“…However, most importantly, the combination of some streptogramin A and Bs can convert a bacteriostatic effect into bactericidal lethality. This, coupled with the observation that bacteria resistant to the MLSB class of antibiotics are still sensitive to streptogramin A inhibition, has led to the use of a streptogramin A and B mixture (in ratio of 3:7) of dalfopristin and quinupristin as a new antimicrobial agent [151] called Synercid ® , marketed by the company RhonePoulenc Rorer.…”

A Re-Emerging Class of Antimicrobial Agents: Streptogramins (Quinupristin/Dalfopristin) in the Management of Multiresistant Gram- Positive Nosocomial Cocci in Hospital Setting

“…hours for Streptocococcus pyogenes) [3,5,16], the quinupristin/dalfopristin association has a potent in vitro synergistic activity (often confirmed by in vivo experiences) with an elevated number of other antimicrobial drugs, including rifampicin, glycopeptides, ciprofloxacin, ampicillin, and some cephalosporins, against meticillinresistant staphylococci, and again glycopeptides, tetracyclines, and penicillins protected by beta-lactamase inhibitors, against E. faecalis strains which test resistant to vancomycin [3,5].…”

“…The overall level of methicillin resistance was around 29% of isolated organisms, with peaks reaching 80%, when coagulase-negative staphylococci were specifically considered [4]. Among these microorganism with predominant hospital isolation, the appearance of methicillin resistance is generally associated to an almost complete lack of in vitro susceptibility to all betalactam derivatives, but also macrolides, lincosamides, and a large part of aminoglycosides and fluoroquinolones, therefore leading to a very limited therapeutic choice [1][2][3]5]. Even Together with the modification of environmental conditions, characteristics of host and microbial flora, and the spectrum of currently available antiinfective compounds (Table 1), other emerging features become prominent, related to the pathomorphism of clinical features of a number of these infections.…”

“…streptococci, pneumococci, and especially coagulase-positive and coagulase-negative staphylococci, Clostridium and Peptostreptococcus spp., and enterococchi, with the partial exception of multiresistant E. faecium (whose susceptibility index is however around 20% of tested strains) [6,16]. The in vitro spectrum of activity of quinupristin/dalfopristin is also extended towards multiple relevant gram-negative pathogens, including Legionella pneumophila, Moraxella catarrhalis, and Mycoplasma pneumoniae [3,5]. The breakpoint values of quinupristin/ dalfopristin recommended for in vitro dilution techniques for minimum inhibitory concentrations (MIC) determination are <1 µg/mL for sensitive microorganisms, 2 µg/mL for moderately susceptible (or "intermediate") organisms, and >4 µg/mL per isolates defined as resistant [5].…”

Peritoneal dialysis-associated peritonitis caused by vancomycin-resistant Enterococcus: Comprehensive review on treatment options

“…Q/P has been shown to be effective in treating various Gram-positive organisms including staphylococci, E. faecium, Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus agalactiae, viridans streptococci, Clostridium perfringens, and Peptostreptococcus spp., etc., as well as against resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA) and VRE. 10 However, its use against VRE is limited to E. faecium because E. faecalis has much higher minimum inhibitory concentration (MIC) of Q/P than that of E. faecium. 11 The pharmacokinetic profile of a single IV dose of Q/P (7.5 mg/kg) has been studied in PD patients and healthy volunteers.…”