Background Vancomycin is a glycopeptide antibiotic active against gram-positive bacteria. Vancomycin pharmacokinetic parameters can vary widely among individuals. Drug monitoring is recommended if the duration of therapy is expected to be more than 72 hours or for patients receiving other nephrotoxic drugs, obese patients, patients with unstable renal function, central nervous system infections, endocarditis, sepsis etc.

Purpose The purpose of this study was to implement the monitoring of vancomycin in specific services.

Material and methods A prospective quasi-experimental study during 9 months (1 October 2015 and 30 June 2016) was carried out in a tertiary-care university hospital. Traumatology and rehabilitation, neurosurgery, neurology, and plastic and maxillofacial surgery services were included. Daily, vancomycin prescriptions were selected from electronic records. The interventions were performed by a pharmacist responsible for monitoring. The variables analysed were:type of infection, request for serum vancomycin concentration, number of determinations per patient, rate of administration of loading dose, number of patients who developed an increase of 0.5 mg/L of serum creatinine after starting treatment with vancomycin. The dose adjustment was performed through the Abottbase PKSystem (PKS) program. The optimal trough concentrations were considered as 15 to 20 mg/L. The first measuring was realised before the 4th to 5th dose and every 48 to 72 hours after every change. To achieve this range, monitoring was performed weekly along with serum creatinine levels. The local guideline recommends the administration of 1 g every 12 hours of vancomycin.

Results A total of 254 patients were enrolled int the study: 137 (53.9%) were male. The median age was 59 (IQR, 47–72) years, weight 78 (IQR, 69–85) kg. Baseline serum creatinine 0.7 (IQR, 0.64–0.82) mg/L. One hundred and thirty-three patients (52.4%) had osteoarticular infections, 43 (17%) skin and soft tissues infections, 23 (9.1%) central nervous system infections and 55 (21.5%) other infections. 199/254 (78.3%) patients were requested for microbiological cultures and in 95/199 (47.7%) were isolated gram-positive bacteria. In 211 (83.1%) patients the vancomicyn was prescribed as 1 g every 12 hours without considering weight. The loading dose was administered in 28 (11.0%) patients. The median duration of the treatment was 6 days (IQR, 4–9). Vancomycin was monitored in 128 (50.4%) patients. The therapeutic range was achieved in 69/128 (53.9%) patients. The median number of determinations per patient was 1 (IQR, 0–1). Three (1.2%)patients developed nephrotoxicity. The number of recommendations made by a pharmacist for dose adjustment were 73 (28.7%).

Conclusion In conclusion, the implementation of monitoring had a favourable uptake. The standard dosage of vancomycin is not enough to achieve the therapeutic range. Loading dosage and patient weight should be considered.

No conflict of interest