• Economic Impact of Pharmacokinetic Monitoring on the use of Oral and Intravenous Busulfan in Patients Undergoing Hematopoietic Stem Cell Transplantation (HSCT)

      Ballard, Erin; Karpen, Stephen; Larriva, Marti; Ballard, Erin; College of Pharmacy, The University of Arizona (The University of Arizona., 2014)
      Specific Aims: Busulfan is a chemotherapy used in conditioning regimens for hematopoeitic stem cell transplant (HSCT) that requires therapeutic drug monitoring (TDM) to reduce ther risk of adverse effects. Variable oral absorption and several studies demonstrating decreased toxicity with the intravenous formulation have led to IV preference despite the lower acquisition cost of oral busulfan. However, these studies failed to consider therapeutic drug monitoring and their results may therefore be flawed. The objective of this retrospective chart review was to determine the adverse effect, outcome profile, and cost-effectiveness of IV versus PO busulfan at a single medical center under TDM. Methods: This quality improvement project was a retrospective cohort analysis using patient data from a single large academic medical center from January 2007 to April 2013. Patients were included if they were 18 years or older and had undergone HSCT using either IV or PO busulfan using standard dosing regimens. This data was then used to design a cost-effectiveness model in order to determine if IV or PO busulfan is cost effective. Main Results: There were 68 subjects receiving autologous transplants and 37 subjects receiving allogeneic transplants that received busulfan as part of their pretreatment therapy and were included in this study. Allogeneic and autologous transplant populations were analyzed separately. In both populations there was no difference in occurrence of pulmonary toxicity, HVOD, or mucositis between the IV or PO groups. IV busulfan was significantly associated with an increased need for patient controlled analgesia in both autologous and allogeneic populations (p=0.038 and 0.028 respectively). Total cost of PO therapy was $30,081 and $30,047 less than IV for autologous and allogeneic transplants, respectively. PO therapy also represented a cost savings of $41 and $57 dollars for autologous and allogeneic transplants, respectively. This was confirmed through bootstrapping technique, which found PO to be dominant to IV busulfan. Conclusion: In conclusion, this study finds PO busulfan to be a therapeutically equivalent and cost saving option as part of a pretreatment regimen for both autologous and allogeneic hematopoietic stem cell transplants when therapeutic drug monitoring is performed.
    • A Retrospective Chart Review on the Effect of Cisplatin Related Kidney Damage When Used With Mannitol Diuresis Versus Saline Diuresis

      Campen, Christopher; Ballard, Erin; Ling, Cynthia; Mak, Sebastian; Campen, Christopher; Ballard, Erin; College of Pharmacy, The University of Arizona (The University of Arizona., 2015)
      Objectives: To compare and evaluate effects on kidney function of mannitol dieresis versus saline diuresis on kidney function with cisplatin therapy. Methods: Patient charts documented between January 2010 and July 2013 were obtained and reviewed from a database of a university associated medical center. The patient’s lowest creatinine clearance (CrCl) and potassium levels during any time in therapy were compared against the baseline. Statistical testing for primary and secondary outcomes was calculated using the Independent-Samples T-Test. Results: A total of 140 patients were reviewed – 68 patients were included in the mannitol arm, 72 in the saline arm. All baseline characteristics reviewed were not statistically different between groups except for sex, which was skewed towards males in the saline arm of the study. Baseline CrCl was 97.14 ml/min in the mannitol arm, and 93.69 ml/min in the saline arm (p=0.91). The average change in CrCl was found to be -16.72 ml/min (95% CI, -21.85 to -11.59) in the mannitol arm, -14.00 ml/min (95% CI, -18.82 to -9.20) in the saline arm; this was not statistically different (p=0.41). There was an average change of -0.31 mmol/L in blood potassium levels in mannitol patients, and a change of 0.014 mmol/L in saline patients; this was found to be significantly different (p<0.01). Conclusions: In this single-center retrospective study, there appeared to be no benefit in using mannitol diuresis over saline diuresis. The use of mannitol incurs additional cost and place additional restrictions on administration.