The Food and Drug Administration (FDA) has issued a Drug Safety Communication regarding the osteoporosis drug denosumab (Prolia). Interim findings from two studies, an ongoing FDA-required manufacturer's long-term safety study of patients with osteoporosis who take denosumab and a separate internal FDA study evaluating hypocalcemia in dialysis patients receiving denosumab, indicate an increased risk of significant hypocalcemia in those with advanced kidney disease, especially in those who also receive dialysis. Some patients needed hospitalization and some died from the hypocalcemia. While denosumab's labeling has always indicated a risk of hypocalcemia, the new data indicate a more severe risk than previously believed.

Denosumab is a human monoclonal antibody with affinity for receptor activator of nuclear factor kappa-[beta] ligand. Blockage of this receptor inhibits osteoclast formation, function, and survival, preventing the breaking down and resorption of bone. Denosumab is administered by subcutaneous injection once every six months.

Denosumab, originally approved in 2010, is currently approved as a treatment for men and postmenopausal women at high risk for fracture from osteoporosis, and for glucocorticoid-induced osteoporosis in men and women at high risk for fracture. It is also approved to increase bone mass in men at high risk for fracture who are receiving androgen deprivation therapy for nonmetastatic prostate cancer and for women at high risk for fracture who are receiving adjuvant aromatase inhibitor therapy for breast cancer.

Prior to initial administration of denosumab, nurses and NPs should assess the patient's laboratory findings for hypocalcemia, as this must be corrected before starting treatment. Nurses and NPs caring for patients with severe chronic kidney disease, especially those on dialysis, should closely monitor the patient for electrolyte imbalances. In addition to hypocalcemia, patients are at risk for hypophosphatemia, since hypocalcemia triggers the production of parathyroid hormone, which stimulates the kidneys to excrete phosphate. Nurses should educate patients on which dietary choices are rich in calcium and vitamin D and explain why supplements of these nutrients are recommended (the denosumab labeling recommends 1,000 mg of calcium and at least 400 IU of vitamin D daily). Patients should understand the importance of frequent monitoring of blood calcium levels. Nurses should teach patients about the symptoms of hypocalcemia, such as unusual tingling or numbness in the hands, arms, legs, or feet; painful muscle spasms or cramps; laryngospasms or bronchospasms that cause difficulty speaking and breathing; vomiting; seizures; and arrhythmias. Nurses and other health care professionals, as well as patients, can report any adverse effects from denosumab to the FDA MedWatch program at http://www.accessdata.fda.gov/scripts/medwatch/index.cfm. To read the FDA's Drug Safety Communication regarding denosumab, go to http://www.fda.gov/drugs/drug-safety-and-availability/fda-investigating-risk-sev.