651. Multi-faceted Intervention to Improve the Rate of Therapeutic Drug Monitoring of Voriconazole
Session: Poster Abstract Session: Pharmacokinetics and Adverse Drug Reactions
Friday, October 21, 2011
Room: Poster Hall B1

Voriconazole (VOR) demonstrates significant variance in serum concentration levels despite standardized dosing.  Lower VOR levels have been associated with lack of infection response and higher levels have been associated with an increased incidence of adverse effects.  Given the variability in serum concentrations, patients on VOR can be subject to either end of this spectrum if therapeutic drug monitoring (TDM) is not employed.  The goal of this project was to increase the rate of TDM among hospitalized patients receiving VOR for 7 days or more.


The University Health System inpatient pharmacy billing database was used to identify patients who had received VOR ≥7 days from January 2010 to February 2011.  All VOR levels were reviewed.  Quality improvement (QI) tools were implemented to identify barriers to ordering drug levels (cause-and-effect diagram) and map out the proposed mechanism of TDM (process improvement flow chart).  Educational interventions included meeting with clinical providers, providing an algorithm on VOR TDM, and discussing the project with hospital pharmacists to aid with dissemination of information to providers.  Information technology specialists created a VOR order set on the electronic medical record (EMR) system that automated the ordering of a VOR level on day 7 of therapy.  A statistical process control chart was utilized to monitor activity and intervention effect.  Interventions were initiated in October 2010.  A chi square test was used for data analysis.


In the pre-intervention time period, 32% of patients (6 of 19) on VOR for 7 or more days had a level ordered.  This increased to 86% (19 of 22 patients) after the intervention.  The odds ratio for having a VOR level sent in the post intervention time period was 13.72 (95% CI 2.90, 65.0; p<0.001).  Of all VOR levels obtained, 32% (8 of 25) were < 1, 56% (14 of 25) were between 1 and 6, and 12% (3 of 25) were >6.


Targeted education of clinical providers and the creation of a VOR order set on the EMR which automated the ordering of VOR levels led to a significant increase in TDM of hospitalized patients.  Variability of VOR levels obtained emphasizes the importance of TDM.   Guidelines for TDM of VOR would optimize the use of this medication.

Subject Category: J. Clinical practice issues

Rachel Rivera, MD1, James Lewis, PharmD2, Susan Spencer3, Alton Powell3, Amruta Parekh, MD, MPH4, Thomas Patterson, MD, FIDSA5 and Jason E. Bowling, MD6, (1)Infectious Diseases, UT Health Science Center San Antonio, San Antonio, TX, (2)University of Texas Health Science Center, San Antonio, Texas, SAN Antonio, TX, (3)UT Health Science Center San Antonio, San Antonio, TX, (4)Dept. of Med, Infectious Diseases and Ctr for Patient Safety and Health Policy,Univ. of Texas Health Science Ctr at San Antonio., San Antonio, TX, (5)Medicine/Infectious Diseases, University of Texas Health Science Center at San Antonio and South Texas Veterans Health Care System, San Antonio, TX, (6)UTHSCSA & STVHCS, San Antonio, TX


R. Rivera, None

J. Lewis, Pfizer, Merck, Astellas: Consultant, Consulting fee

S. Spencer, None

A. Powell, None

A. Parekh, None

T. Patterson, Astellas, Basilea, Pfizer, Merck: Consultant, Investigator and Scientific Advisor, Research grant

J. E. Bowling, None

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.