Life-threatening hyperkalemia following zoledronic acid infusion for Paget's disease: a case report

Adverse events associated with bone-directed therapies in patients with cancer

Bone metastatic disease may lead to serious adverse events in patients with cancer. Bone-directed therapies, including bisphosphonates such as pamidronate and zoledronic acid and the human monoclonal antibody denosumab, are currently approved for the prevention of bone-related adverse events. However, despite the benefits of these drugs, they may cause side effects that are mostly associated with dosages and treatment durations. These side effects range from more frequent, mostly mild, and generally self-limited side effects-such as fever, myalgias, arthralgias, and electrolyte imbalances-to less frequent and more severe side effects such as medication-related osteonecrosis of the jaw and atypical femoral fractures. The purpose of this review is to familiarize clinicians with the literature regarding adverse events associated with bone-directed therapies in patients with cancer. It is important to be aware of these possible adverse events and to educate patients about the predisposing factors associated with side effects from bone-directed therapies and the preventive measures necessary to decrease the risk of occurrence.

Symptomatic Hypocalcemia Associated with Zoledronic Acid Treatment for Osteoporosis: A Case Report

Intravenous bisphosphonates are widely used in the management of solid tumors, metastatic bone disease, metabolic bone diseases and hypercalcemia of malignancies. Recently, yearly intravenous injections of zoledronic acid, one of the potent nitrogen-containing bisphosphonates, have also been approved for the prevention and treatment of osteoporosis. Although infrequently observed, asymptomatic hypocalcemia mainly due to intravenous bisphosphonates has been documented. Here we report a female patient who exhibited profound symptomatic hypocalcemia after receiving intravenous zoledronic acid as treatment of postmenopausal osteoporosis. The patient was not assessed for calcium status prior to the intravenous bisphosphonate therapy, and she was later found to have severe vitamin D deficiency. To our knowledge, this is the first patient with symptomatic hypocalcemia to be reported after zoledronic acid was approved for the management of osteoporosis. We highlight the importance of evaluating calcium and vitamin D levels before initiating intravenous bisphosphonate treatment, particularly in the presence of widespread vitamin D deficiency and the likelihood of future increases in the prescription of intravenous bisphosphonates.