[Monitoring of vancomycin plasma levels in patients undergoing hemodialysis]

The aim of this study was to confirm whether patients undergoing dialysis and treated with vancomycin 1 g/week or 500 mg/48 hours reach optimum plasma levels (10-25 mcg/ml).

Thirty two patients were included with a total number of 34 infectious events. The most commonly used dose was 1 g/week (67.6% of infectious events), versus 500 mg/48 hours (32.4%). Low ultrafiltration membranes were used more frequently (64.7%) than high ultrafiltration membranes (35.3%).Vancomycin was infused over an one-hour period during the last hour of the hemodialysis session and plasma samples were drawn prior to the beginning of the session. Samples were analyzed using fluorescent polarization immunoassays.

Mean concentration results for the total population did not reach optimum values (10-25 mg/ml). In the group receiving 500 mg/48 hours, optimum mean values were not reached in any of the determinations, whereas in the group receiving 1 g/week, optimum values were reached in the fourth determination. Mean plasma levels of the antibiotic were below optimum values, regardless the type of membrane used, either low or high ultrafiltration.

Based on the above results, we recommend titration of the vancomycin dose in this group of patients and the administration of a loading dose of 20 mg/kg during the last hour of the hemodialysis session, followed by a maintenance dose of 7 mg/kg after each session, as well as the monitoring of the drug levels in this group of patients.