title: Are serum levels of vancomycin useful in the first week of therapy?
abstract: Controversy exists regarding the need to monitor serum concentrations of vancomycin with some investigators recommending measurement of peak and trough concentrations in the first week of therapy and regularly thereafter, whereas others contend that empiric dosing produces safe and effective drug concentrations so that testing is unnecessary. Since vancomycin concentrations are measured, routinely in our hospital in the first week of therapy, we conducted a 12 month study to assess their clinical value in patients who were treated when gram positive cocci were detected in blood culture smears. One-hundred-five patients had gram positive cocci on blood culture smears. These bacteria were pathogens in 15 patients with Staphylococcus aureus and in 18 with coagulase negative staphylococci based on microbiologic criteria and a chart review confirming their clinical significance. Ten patients with S. aureus and 8 patients with coagulase negative staphylococci that were pathogens and 10 patients with coagulase negative staphylococci that were contaminants were treated with vancomycin. Serum peak and trough concentrations of vancomycin obtained within the first 5 days of therapy in these 28 patients were 14 to 40 micrograms/ml and 4.8 to 20 micrograms/ml. These concentrations were much above the MIC's of the microorganisms (< 4 micrograms/ml). Five patients had increases of serum creatinine of more than 0.6 mg% and in each patient the increases were attributable to other causes-shock, heart failure, and preexisting renal failure. Fifty five peak and trough concentrations 19 of which were drawn in patients with contaminated cultures were measured at a cost of $2,475.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D016470:Bacteremia / Q000097:blood* / Q000188:drug therapy; D017046:Cost Savings; D003428:Cross Infection / Q000097:blood* / Q000188:drug therapy; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D016903:Drug Monitoring / Q000191:economics; D016908:Gram-Positive Bacterial Infections / Q000097:blood* / Q000188:drug therapy; D006095:Gram-Positive Cocci / Q000187:drug effects; D006801:Humans; D014640:Vancomycin / Q000008:administration & dosage / Q000493:pharmacokinetics*
chemical_list: D014640:Vancomycin