Factors influencing the vancomycin trough level in patients admitted at King Fahad Specialist Hospital, Qassim, KSA.

OBJECTIVE

Although vancomycin is an effective antibiotic against methicillin-resistant Staphylococcus aureus, its usage is often associated with nephrotoxicity which necessitates optimization of the vancomycin dose to be both precise and appropriate. To achieve this, the importance of therapeutic drug monitoring arises, and serum trough vancomycin concentrations are the most accurate and practical method for monitoring vancomycin effectiveness and even risk of nephrotoxicity. This study evaluated the influences on the trough levels of vancomycin given to admitted patients at King Fahad Specialist Hospital (KFSH).

PATIENTS AND

METHODS

This cross-sectional hospital-based study has been conducted at KFSH among 197 patients, of which 53.3% were male and 46.7% were female. They received intravenous vancomycin at intermittent dose of 30 mg/kg/day with no clinical or laboratory renal impairment. The serum was drawn trough concentrations within 15 to 45 minutes before the fourth vancomycin dose.

RESULTS

One-way ANOVA test showed a significantly higher trough level of vancomycin among females, patients older than 50 years, and CCU and CSICU admitted patients (p-value < 0.05). Spearman correlation test also showed significant correlation with the serum vancomycin trough levels, site of infection (Rho=0.406, p=0.009), age (Rho=0.341, p=0.044) and patients' admission (Rho=0.321, p=0.041).

CONCLUSIONS

Even at body adjusted dosing, vancomycin serum trough levels varied among patients with significant variations of age, gender, site of infection and type of admission, especially CCU and CSICU, which raises the concept of dose individualization, age and gender considerations especially among critically ill patients.