Evaluation of Vancomycin Dosing and Monitoring in Adult Medicine Patients

Abstract

Purpose To assess the clinical impact of a vancomycin dosing protocol and monitoring tool on initial dose, dosing interval, and trough concentrations in adult medicine patients. Methods This was a retrospective chart review of adult medicine patients who received at least one dose of vancomycin and were admitted during the pre-implementation period, February 1 to April 2009, or during the post-implementation period, June 1 to October 31, 2009. All outcomes for patients in the pre-implementation group were compared to those in the post-implementation group. The primary outcomes were frequency of appropriate initial vancomycin dose and dosing interval. The secondary outcomes included frequency of appropriate initial vancomycin trough concentrations, mean number of levels drawn per patient, and mean duration of therapy. Results A total of 450 patients were identified, with 225 patients in each study group. Patients with an appropriate initial vancomycin dose significantly increased in the post-implementation group (56% vs 40%; P < .001). The number of patients with an appropriate original dosing interval (67% vs 63%; P = 0.32), appropriate initial trough concentration (44% vs 45%; P = 0.89), mean number of levels drawn (1.9 vs 2.1; P = 0.56), and duration of therapy (4.9 vs 5.0; P = 0.77) was similar between the 2 groups. Conclusions The implementation of a vancomycin empiric dosing protocol and monitoring tool had a significant impact on the initial dose. Further education regarding vancomycin dosing and monitoring is warranted to improve initial dosing interval, initial trough concentration, number of levels drawn, and duration of therapy.

Prospective Trial of a Novel Nomogram to Achieve Updated Vancomycin Trough Concentrations

“…In contrast, our nomogram allows the clinician to choose the appropriate trough goal, 10–15 mcg/mL or 15–20 mcg/mL, based on the patient's indication for therapy. Our results are comparable to those in the Devabhakthumi et al study, in which 44% versus 45% of subjects were in the therapeutic range, respectively, and this may be due to our similar inclusion criteria which was very broad with few exclusion criteria, making the nomograms broadly applicable [11]. Our results are lower than those seen in the Kullar et al study, 44% versus 58%, respectively, and may be due to the fact that the patients included in the Kullar et al study were generally stable.…”

“…In comparison to the nomogram developed by Devabhakthumi et al, our nomogram is similar in design, utilizing weight to determine the vancomycin dose and creatinine clearance to determine the dosing interval [11]. However, the Devabhakthumi nomogram did not differentiate between obese and nonobese patients and also did not separate trough goals.…”

“…However, the Devabhakthumi nomogram did not differentiate between obese and nonobese patients and also did not separate trough goals. A therapeutic trough in the Devabhakthumi et al study was considered appropriate if it fell anywhere between 10–20 mcg/mL regardless of the patients' indication for therapy [11]. In contrast, our nomogram allows the clinician to choose the appropriate trough goal, 10–15 mcg/mL or 15–20 mcg/mL, based on the patient's indication for therapy.…”

“…The second dosing protocol by Devabhakthumi et al was a retrospective analysis utilizing the patient's weight to determine dose and renal function to determine the dosing interval. Although results showed that an increased number of patients were initiated on an appropriate vancomycin dose, which authors defined as 15 mg/kg/dose, the percentage of patients achieving appropriate trough concentrations was not improved with the implementation of the dosing protocol [11]. Also, no adjustment was made to the dosing protocol if the patient was obese or nonobese.…”

Evaluation of the Effectiveness of Dose Individualization to Achieve Therapeutic Vancomycin Concentrations

“…These findings are similar to previous first‐world studies that reported therapeutic trough concentrations of 42% to 45% . Achievement of therapeutic trough concentrations was 21% higher when computerized TDM procedures were adhered to.…”