Therapeutic drug monitoring of vancomycin in an obese patient with renal insufficiency

We report the pharmacokinetics of vancomycin in an obese patient with renal insufficiency using pharmacokinetic equations, and comparing them with actual levels. A 47-year-old man with morbid obesity had a complicated hospital course with acute renal failure. Due to sputum growth of coagulase-negative Staphylococcus aureus, vancomycin 1500 mg intravenously twice daily was given empirically. Peak and trough plasma concentrations were drawn at steady state. Based on levels, true pharmacokinetic parameters for the patient were calculated using equations. This revealed that calculating individual pharmacokinetic parameters using equations may be a valid tool for dosing vancomycin in obese patients with renal insufficiency.