Impact of a Renal Drug Dosing Service on Dose Adjustment in Hospitalized Patients with Chronic Kidney Disease

Abstract

Background: Appropriate drug selection and dosing for patients with chronic kidney disease (CKD) is important to avoid unwanted drug effects and ensure optimal patient outcomes. Objective: To assess the rate of inappropriate dosing in patients with CKD in a nephrology unit and to evaluate the impact on dose adjustment, adverse drug events (ADEs), and drug cost of having a pharmacist accompany a team of physicians on their rounds. Methods: This was a comparative study with a preintervention and postintervention design. The preintervention phase served as the control; it was prospective and observational only and was conducted from the beginning of February to the end of May 2007. The second phase (intervention phase) was conducted from the beginning of March to the end of June 2008. Two random samples of 300 patients with an estimated creatinine clearance less than or equal to 50 mL/min were included. During the intervention phase, a clinical pharmacist made rounds with the nephrology unit team and gave dosing adjustment recommendations when needed. A collection of reliable and up-to-date drug information references that are commonly used globally were used during the intervention. Results: In the preintervention group, drug dosage adjustment or avoidance, based on renal function, was necessary in 607 of 2814 (21.6%) prescriptions. Of these, 322 (53.0%) did not comply with guidelines. In the intervention group, adjustment was necessary for 640 of 2981 (21.5%) prescriptions. The pharmacist made 388 recommendations related to dosing adjustment, 212 (54.6%) of which were accepted by physicians. Clinicians' noncompliance with dosing guidelines decreased to 176 (27.5%) (p < 0.001). In the preintervention group, 64 (21.3%) patients had a suspected ADE, with a total of 73 events. In the intervention group, this number was significantly lower with 49 events in 48 (16.0%) patients (p < 0.05). The intervention resulted in drug cost savings of $2250 US. Conclusions: A renal drug dosing service for patients hospitalized with CKD can increase the proportion of drug dosing that is adjusted to take into account renal function. This can save drug costs and may prevent ADEs.