The effect of renal clearance on serum trough concentration of vancomycin in elderly patients with severe pneumonia

Abstract

To investigate the effect of renal clearance on serum trough concentration of vancomycin in elderly patients with severe pneumonia. This was a prospective non-interventional study. Forty-two elderly patients with severe pneumonia and normal level of serum creatinine were enrolled from November 2013 to October 2014. The patients included 25 males and 17 females, aged 60-83 years (median 74 years). The renal clearance was measured, and the vancomycin regimen and rate of serum trough concentration achieving guideline-recommended target of 15-20 mg/L were investigated. The factors influencing trough concentration of vancomycin were analyzed using the general linear model. The vancomycin regimens were 1 g/ 12 h (17 cases), 0.5 g/8 h (14 cases) and 0.5 g/12 h (11 cases), and their median and range of serum concentrations were 14.9(2.4-28.5)mg/L, 16.2(2.8-27.8)mg/L and 11.6 (5.9-19.9) mg/L, respectively. The guideline-recommended target trough concentration of 15-20 mg/L was reached in only 10 patients, while trough concentration lower than 15 mg/L was found in 22 patients and higher than 20 mg/L in 10 patients. General linear model analysis showed that creatinine clearance rate(CCR) and dose of vancomycin per kilogram of body weight per day were independent influencing factors for trough concentration (both P<0.05). There were 8 patients with CCR≥130 ml·min(-1)·(1.73 m(2))(-1) (augmented renal clearance), 22 patients with 70≤CCR<130 ml·min(-1)·(1.73 m(2))(-1) and 12 patients with CCR<70 ml·min(-1)·(1.73 m(2))(-1,) and vancomycin trough concentration below 15 mg/L was found in 7, 11 and 4 patients, respectively. CCR was an independent influencing factor for trough concentration of vancomycin, and augmented renal clearance increased the risk of subtherapeutic trough concentration of vancomycin.