Advances in Pharmacoepidemiology and Drug Safety

Abstract

Optimizing Vancomycin Dosing in Obese and Morbidly Obese Patients with MRSA Infections

Eddie Grace, Nancy Hope Goodbar and Jaime A. Foushee

Approximately 275,000 of these hospitalizations were due to Methicillin-resistant Staphylococcus aureus (MRSA) infections which resulted in over 19,000 deaths. Since VCN’s introduction over 6 decades ago, it has been studied in various patient populations such as those with renal disease, burns, and cystic fibrosis. However, until recently, extremely limited data has been available for the use of VCN in obese patients. Due to the differences in VCN pharmacokinetics in obese patients compared to non-obese patients, use of PK parameters in obese patients which were originally derived from non-obese patients results in erroneous dosing of VCN leading to clinical failures and increased incidence of adverse effects. PK parameters such as vancomycin clearance, volume of distribution, protein binding, and creatinine clearance (CrCl) in obese patients will be discussed in addition to studied methods to optimize vancomycin dosing in obese patients by using loading doses, weight based dosing, and area under the curve to minimum inhibitor concentration ratio (AUC:MIC). Due to the variability in dosing of obese patients compared to non-obese patients, VCN maximum doses and the incidence of nephrotoxicity will also be discussed.