Severe Hypocalcemia and Dramatic Increase in Parathyroid Hormone after Denosumab in a Dialysis Patient: A Case Report and Review of the Literature

Chronic kidney disease-mineral and bone disorder (CKD-MBD) is frequently present in advanced stages of chronic kidney disease (CKD) patients with high risk of fracture and elevated socioeconomic burden. Denosumab, an injectable human monoclonal antibody with affinity for nuclear factor-kappa ligand (RANKL), is an effective treatment for osteoporosis in postmenopausal women and men. Unlike the bisphosphonates, the pharmacokinetics and pharmacodynamics of denosumab are not influenced by the renal function and are being increasingly used for patients having CKD-MBD with low bone mineral density (BMD) to reduce the risk of fragility fractures. Hypocalcemia is a known side effect of this drug along with compensatory increase in parathyroid hormone (PTH). However, limited information is available in the literature regarding this potentially life-threatening side effect with denosumab in end-stage renal disease (ESRD) patients on dialysis. We present a patient with ESRD on peritoneal dialysis who developed severe symptomatic hypocalcemia and dramatic increase in PTH following denosumab therapy. She was conservatively managed with calcium supplementation and appropriate adjustment in calcium dialysate. We have also reviewed the literature on the use of denosumab in dialysis patients and looked at additional factors that may precipitate severe hypocalcemia in these patients. We believe that denosumab should be used with caution in dialysis patients since it may lead to profound hypocalcemia. Clinicians should ensure special attention in recognizing patients at risk of developing this serious adverse effect, so that prompt treatment and preventive strategies can be implemented.