Why monitor peak vancomycin concentrations?

Peak and trough serum concentrations are routinely measured to monitor vancomycin therapy. Optimal therapy depends upon maintaining a concentration above that necessary for antibacterial activity and is therefore determined by the trough concentration. I determined the post dose increases in serum drug concentrations in routine clinical practice in adult patients without renal failure. Mean increases of 16.6 mg/L (SD 6.1) (peak samples collected 1 h post infusion) were measured from 165 paired samples. The results suggest that as long as trough concentrations do not exceed 15 mg/L, peak levels will not exceed normally accepted safe concentrations, and therefore do not need to be measured.