title: Severe hypocalcemia after denosumab in a patient with acquired Fanconi syndrome.
abstract: We report the case of a 48-year-old man with acquired Fanconi syndrome due to IgG-kappa monoclonal gammopathy, who received a single dose of denosumab 60 mg for secondary prevention of skeletal fractures, in conjunction with oral calcium and vitamin D supplementation. The treatment was complicated with a severe, symptomatic hypocalcemia occurring 1 month after the injection and necessitating 4 weeks of intravenous calcium gluconate therapy. Similarly to bisphosphonates, inhibitors of the receptor activator of nuclear factor kappa-B ligand may not be appropriate for the treatment of acquired Fanconi syndrome and other forms of osteomalacia regardless of the degree of renal insufficiency and vitamin D levels. Clinicians should carefully interpret the radiographic and bone densitometry results in light of diverse mechanisms of bone demineralization and potential dependence of calcium homeostasis on high bone turnover.
authors.affiliation: Memorial Hospital of Rhode Island, 111 Brewster St., Pawtucket, RI, 02860, USA.
authors.forename: H
authors.initials: H
authors.lastname: Shafqat
authors.forename: K F
authors.initials: KF
authors.lastname: Alquadan
authors.forename: A J
authors.initials: AJ
authors.lastname: Olszewski
mesh_terms: D061067:Antibodies, Monoclonal, Humanized / Q000009:adverse effects* / Q000627:therapeutic use; D050071:Bone Density Conservation Agents / Q000009:adverse effects* / Q000627:therapeutic use; D002118:Calcium / Q000627:therapeutic use; D000069448:Denosumab; D005198:Fanconi Syndrome / Q000150:complications*; D006801:Humans; D006996:Hypocalcemia / Q000139:chemically induced* / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D010018:Osteomalacia / Q000188:drug therapy / Q000209:etiology; D058866:Osteoporotic Fractures / Q000209:etiology / Q000517:prevention & control; D053245:RANK Ligand / Q000037:antagonists & inhibitors
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D050071:Bone Density Conservation Agents; D053245:RANK Ligand; D000069448:Denosumab; D002118:Calcium