According to the most recent United States Renal Data Service (USRDS) compilation, infection continues to exact a heavy toll among dialysis patients. The most recent USRDS mortality rate attributable to sepsis for dialysis patients was 27.0%. Despite the reported improvements in quality of life and medical complications provided by short-daily HD, infection will likely remain a persistent medical issue for dialysis patients. As a result, the appropriate provision of antibiotic therapy to patients receiving hemodialysis will remain paramount. Currently, there are no studies that have evaluated the pharmacokinetics of the commonly used antibiotics in the growing short-daily HD population. With no specific guidelines, pharmaco-kinetic estimations and frequent drug levels have been utilized to direct antibiotic dosing. This is likely not the best therapeutic approach and may not be the most cost-effective. This study will attempt to address this deficit in the clinical knowledge for three commonly used antibiotics, vancomycin, levofloxacin and gentamicin. The drug dosing guidelines developed from this study will ensure that this patient population receives the optimum antibiotic therapy to treat their infection in the most cost-effective manner.