Abstract: PUB055
High-Dose Denosumab for the Management of Immobilization-Related Hypercalcemia in a Patient on Maintenance Hemodialysis: A Case Report
Session Information
Category: Bone and Mineral Metabolism
- 402 Bone and Mineral Metabolism: Clinical
Authors
- Elnazer, Weam, Nephrology Center, Armed Forces Hospitals Southern Region, Khamis Mushayt, Saudi Arabia
- Zaitoun, Mohammad, Pharmacy Department, Armed Forces Hospitals Southern Region, Khamis Mushayt, Saudi Arabia
- Al-Alsheikh, Khalid, Nephrology Center, Armed Forces Hospitals Southern Region, Khamis Mushayt, Saudi Arabia
Introduction
Immobilization-related hypercalcemia arises due to a higher rate of osteoblastic bone formation compared to osteoclastic bone resorption. Renal impairment increases the risk of immobilization-related hypercalcemia. There is limited evidence about the safety and efficacy of denosumab in the management of immobilization-related hypercalcemia in hemodialysis (HD) patients.
Case Description
We report a case of successful treatment of immobilization-related hypercalcemia with denosumab 120 mg. A 55-year-old woman admitted to the ICU with suspected catheter-related bacteremia that led to septic shock. After 13 days of admission, the patient’s corrected serum calcium rose to 3.39 mmol/l from a baseline of 2.52 mmol/l despite calcium carbonate and alfacalcidol discontinuation. Cinacalcet 60 mg once daily for 10 days, subcutaneous Calcitonin 250 mcg/dose for 6 days, a single dose of intravenous Zoledronic acid 4 mg, and a single dose of subcutaneous denosumab 60 mg were sequentially administered without response. Thus, subcutaneous denosumab 120 mg was administered and resulted in a gradual decline of the corrected calcium level from 4.18 mmol/l to 2.45 mmol/l over 3 weeks. Corrected calcium level was maintained below 2.8 mmol/l for 2 months later without notable adverse reactions. The patient's serum phosphorus level and PTH were within the normal ranges during the whole admission period.
Discussion
The management of immobilization related hypercalcemia in ESRD patients include withholding calcium and vitamin D, HD using a low-calcium dialysate (not available in our setting), Bisphosphonates, Cinacalcet, Calcitonin, and Denosumab. In our case, all management options were not effective except high dose denosumab. Cinacalcet has poor tolerability due to its common gastrointestinal side effects. Bisphosphonates lack of efficacy was possibly due to their limited antiresorptive action. Moreover, Bisphosphonates safety in ESRD patients is not well established and they are not recommended in this population for non-malignancy uses. Unlike Bisphosphonates, Denosumab lacks the need for renal dose adjustment. Besides, Denosumab has a rapid onset and extended duration of action. Our case showed that High-dose denosumab could be effective and safe for the management of immobilization-related hypercalcemia in HD patients.