Comparison of Weight Based Parenteral Calcitonin Dosing Strategies: Total Versus Ideal Body Weight

Background: Current guidelines and the package insert do not define the appropriate body weight to dose calcitonin and there is a lack of literature evaluating dosing via ideal body weight (IBW). Objective: The objective of this study is to compare calcium reduction among patients with severe hypercalcemia treated with calcitonin via total body weight (TBW) versus IBW. Methods: This was a single-center retrospective analysis of data gathered within a quality improvement project to standardize parenteral calcitonin utilization. The primary outcome was to compare calcium reduction within 24 hours of treatment initiation. Secondary outcomes included calcium reduction within 48, 72, and 96 hours, the incidence of hypocalcemia, the incidence of rebound hypercalcemia, and the average wholesale price (AWP) expenditure. Results: A total of 48 patients met inclusion criteria, with 25 patients in the TBW group and 23 patients in the IBW group. The primary outcome of change in corrected calcium within 24 hours was not statistically significant between groups (1.1 mg/dL vs 1.7 mg/dL, P = .12). Serum calcium levels and change from baseline were followed up to 96 hours, and no difference was noted between groups. Additional secondary outcomes were not significant, with the exception of AWP expenditure, which was statistically lower in the IBW group ($11 274.0 vs $7516.0, P = .02). While no difference was found in the total number of doses administered or total units consumed (600.0 units vs 400.0 units, P = .06), a significant difference was found in the average dose (364.0 units vs 239.0 units, P < .00001). Conclusion: This study suggests that dosing parenteral calcitonin via IBW achieved a similar reduction in calcium compared to TBW. Moreover, dosing via IBW resulted in a significant reduction in average dose and in AWP expenditure when compared to TBW. This approach offers an alternative dosing strategy that uses less medication, without compromising efficacy.