Vancomycin therapeutic drug monitoring (TDM): is there a consensus view? the results of a UK national external quality assessment scheme for antibiotic assays (UK NEQAS) questionnaire

C.M. Tobin, J.M. Darville, A.H. Thomson, G. Sweeney, J.F. Wilson, L.O. White

Research output: Contribution to journalArticlepeer-review

58 Citations (Scopus)


This study investigated vancomycin therapeutic drug monitoring (TDM) and issues related to patient management. Questionnaires were distributed to 310 participants in the UK National External Quality Assessment Scheme (NEQAS) for Antibiotic Assays. The response rate was 57.4%. The majority (76%) had an 'in-house' assay service based, almost exclusively, in the microbiology department, and a fluorescence polarization immunoassay (FPIA) was used by 97%. Almost half (48.7%) had an assay service available for 24 h/day, 7 days/week and 92.7% expected same-day results. The majority (80%) had issued guidelines for vancomycin use. A 12 hourly initial dosing regimen was used by 89%. Trough assay samples were taken <10 min before the dose by 91.5%. For post-dose assay samples, 44% took a sample at 1 h, 28% at 2 h and the remainder at 'other' times. For trough target ranges, 93% quoted <10 mg/L or 5-10 mg/L. There was no consensus with regard to post-dose assay sample times and 23 ranges were quoted. The majority (74.4%) regarded a trough level of >or=10 mg/L as 'toxic' but 13 concentrations were quoted as toxic post-dose measurements. In conclusion, there was a wide variability and poor consensus with regard to post-dose vancomycin assay sampling times, target ranges and what constituted a toxic level.
Original languageEnglish
Pages (from-to)713-718
Number of pages6
JournalJournal of Antimicrobial Chemotherapy
Issue number5
Publication statusPublished - 2002


  • therapeutic drug monitoring
  • antibiotic assays

Cite this