virginiamycin and Peritonitis

The pharmacodynamic and pharmacokinetic characteristics of antimicrobial agents are the two fundamental pharmacological components which provide a rationale for the choice of therapy for intraabdominal infections, and especially serious infections. The most important PK-PD parameters are well known which can potentiate therapeutic efficacy. Antimicrobial agents can be subdivided into categories based on whether their activity is dependent on concentration or exposure time. Therefore, a correct dosing regimen for the time-dependent molecules (i.e. beta-lactams, linezolid, tigecycline) should prolong the maximum exposure time to maintain serum levels over the minimum inhibitory concentration (MIC). The concentration-dependent molecules, on the other hand, which include aminoglycosides and fluoroquinolones, should be given in order to reach maximum concentrations, since they are bactericidal in direct proportion to their concentrations and possess a prolonged post-antibiotic effect.

Topics: Abdominal Abscess; Acetamides; Aminoglycosides; Anti-Bacterial Agents; Anti-Infective Agents; beta-Lactams; Digestive System Diseases; Drug Therapy, Combination; Fluoroquinolones; Humans; Linezolid; Metronidazole; Microbial Sensitivity Tests; Minocycline; Oxazolidinones; Peritonitis; Sepsis; Tigecycline; Treatment Outcome; Virginiamycin

Peritonitis remains a major complication in patients undergoing peritoneal dialysis. The most recent ISPD guidelines for the empiric initial treatment of peritonitis recommend the use of antibiotics that provide coverage against Gram-positive organisms (vancomycin or cefazolin) and Gram-negative organisms (a third-generation cephalosporin or an aminoglycoside). However, there are some situations in which this regimen may not be desirable. Concerns of resistant organisms, changing microbiology, drug toxicity, or difficulties administering therapy may lead a provider to modify the initial regimen. Drug resistant Staphylococcus aureus strains and Enterococcus strains may require administration of newer agents such as linezolid, quinipristin/dalfopristin, or daptomycin. Many centers have reported that, over time, the microbiology at those institutions has been changing. Some centers have reported a significant decrease in gram positive organisms and increase in extended spectrum beta-lactamase (ESBL) organisms. It is important for each center to examine its microbiology to document such trends. Although the currently recommended therapies have low toxicities, it is possible that concerns for untoward side effects in an individual patient may dictate changing the regimen. Finally, there is evidence from many prospective studies that monotherapy with different agents (oral quinolones or cefepime) is efficacious; if ease of therapy is a consideration, these may also be appropriate agents.

Topics: Acetamides; Anti-Bacterial Agents; Daptomycin; Drug Resistance, Bacterial; Humans; Linezolid; Oxazolidinones; Peritoneal Dialysis; Peritonitis; Staphylococcal Infections; Staphylococcus aureus; Virginiamycin

Topics: Adult; Aged; Anti-Bacterial Agents; Enterococcus faecium; Female; Gram-Positive Bacterial Infections; Humans; Male; Middle Aged; Peritoneal Dialysis, Continuous Ambulatory; Peritonitis; Virginiamycin