Sample size was determined on the basis of a predicted OR of 3, with a desired power of 80% and a of 0.05. It was estimated that 100 controls and 50 cases (2:1 ratio) would be required. However, because of difficulty in locating an adequate number of controls, the ratio of cases to controls was [...]

A retrospective unmatched case—control study was conducted to examine vancomycin dosing frequency as a function of age. The study was conducted at St Paul’s Hospital, a 520-bed acute care teaching hospital located in downtown Vancouver. The pharmacy’s computer system was used to identify patients admitted to the hospital between October 2002 and August 2006 for [...]

INTRODUCTION Vancomycin is the drug of choice for hospital inpatients with severe methicillin-resistant Staphylococcus aureus (MRSA) infections. Although vancomycin is an effective bactericidal agent, literature reports of antibiotic failure with this drug are relatively common. Efforts to minimize the risk of antibiotic failure have led to a focus on how best to opti­mize vancomycin pharmacokinetics. [...]

THE “GOSPEL” OF PATIENT ASSESSMENT We feel that any potential new “gospel” for pharmacists should not be based on the debate between the CG and MDRD equations, but rather should focus on enhancing the overall approach to drug use and dosing assessment in individual patients. In our experience, too many pharmacists make dosing recommendations according [...]

WHICH TESTAMENT SHOULD WE FOLLOW? Various opinions on this topic have been expressed by pharmacy’s “disciples”, and one must carefully consider the underlying beliefs in an effort to get at the “truth”. Belief 1: Because the MDRD equation is more accurate, it should be used for drug dosing.

THE NEW TESTAMENT VERSUS THE OLD TESTAMENT The National Kidney Foundation has recently reviewed the literature related to the predictive performance of these equations for GFR, as measured by iothalamate or iohexol clearance. For the CG equation, the proportion of estimates within 30% of actual (measured) GFR ranged from 48% to 95%. The full MDRD [...]

BLASPHEMY? Although not always stated, renal drug dosing recommendations are based on comparisons of relative (not actual) renal function. In other words, they should be based on the degree of renal function of the patient in question in comparison with a “normal” patient (i.e., a 70- kg man). Clinicians should be aware that when using [...]