Journal of Clinical Case Reports

Denosumab-Induced Central Nervous System Events in Postmenopausal Women without Hypocalcemia

Abstract

Fahad O. Alatawi, Najah S. Alanazi and Khalidah A. Alenzi

Denosumab is an effective human monoclonal antibody used for postmenopausal women with osteoporosis at high risk for fracture. There are serious adverse effects associated with the use of denosumab, such as hypocalcemia, hypophosphatemia, hypomagnesemia, and increased blood alkaline phosphatase. Hypocalcemia associated with the use of denosumab can lead to central nervous system complications (seizure) in chronic kidney disease patients (CKD 4-5D). The patient, in this case, had osteoporosis and started a denosumab regimen (60 mg subcutaneous injection every 6 months for 2 years) with normal renal function and magnesium and calcium levels but developed reversible convulsion, amnesia, irritability hallucination, marked elevation Gamma-Glutamyl Transferase (GGT), and slight elevations in alkaline phosphatase and Aspartate Aminotransferase (AST). In all previously documented cases, CNS events after the administration of denosumab were associated with hypocalcemia or renal impairment. We hereby report a case of reversible convulsion following denosumab administration for the treatment of osteoporosis in postmenopausal women with normal renal functions, endocrine, and metabolic profiles. The findings of this study suggest careful monitoring of serum levels of calcium, phosphorus, and magnesium and symptoms of CNS events before initiation and during denosumab therapy.