Vancomycin, having the wide spectrum of activity for Gram (+) bacteria, is the mainstay treatment formethicillin resistant Staphylococcus aureus (MRSA) infection. The trough concentration of vancomycin (CTrough) is the most practical method for therapeutic monitoring of vancomycin. The recommended CTrough level of vancomycin is 15-20 mg/L while that of the acceptable range is 5-20 mg/L. CTrough less than 10mg/L is associated with the development of resistant strains whereas that of above 20 mg/L is associated with acute nephrotoxicity.

To determine CTrough/MIC of vancomycin and the microbiological outcome in haemodialysis patients with end stage renal disease

The hospital-based observational study was done in 19 end stage renal disesased patients undergoing haemodialysis twice weekly, who were prescribed IV vancomycin by the nephrologists for Gram (+) bacteremia. The HPLC-UV method was used to measure the CTrough of vancomycin at the steady state concentration; immediately before the 3rd dose of vancomycin. The MICs of individual patients were obtained from the blood culture test before vancomycin administration. The microbiological outcome was evaluated by the blood culture test after completion of the 5th dose of vancomycin.

Two patients had CTrough/MIC value < 5 (subtherapeutic value), 5 patients had CTrough / MIC value within 5 to 20 (therapeutic value) 12 patients had CTrough / MIC value >20 (supra-therapeutic value). After completion of 5th dose of vancomycin, twelve patients had sterile blood culture result and seven patients had Gram (-) bacteremia which are not under the activity of vancomycin.

In this study, only five patients achieved therapeutic CTrough/MIC value. The remaining patients have either the possibility of resistant strains or the vulnerability of acute nephrotoxicity. Therefore, this study proves that therapeutic monitoring of vancomycin is important to achieve the optimum clinical effectiveness in patients with end stage renal disease undergoing haemodialysis.