The FDA is requiring a boxed warning in the label of denosumab (Prolia – Amgen), a monoclonal antibody that inhibits osteoclasts, about an increased risk of severe hypocalcemia in patients with advanced chronic kidney disease (CKD; eGFR <30 mL/min/1.73 m²), particularly those on dialysis. FDA-approved indications for Prolia are listed in Table 1.

The FDA is requiring a boxed warning in the label of denosumab (Prolia – Amgen), a monoclonal antibody that inhibits osteoclasts, about an increased risk of severe hypocalcemia in patients with advanced chronic kidney disease (CKD; eGFR <30 mL/min/1.73 m²), particularly those on dialysis. FDA-approved indications for Prolia are listed in Table 1.

US guidelines recommend pharmacologic therapy for postmenopausal women with a bone density T-score (standard deviation from normal mean values in healthy young women) of -2.5 or below in the lumbar spine, femoral neck, total hip, or distal radius, a T-score between -1.0 and -2.5 and a history of fragility (low-trauma) fracture of the hip or spine, or a T-score between -1.0 and -2.5 and a FRAX 10-year probability of ≥3% for hip fracture or ≥20% for major osteoporotic fracture (hip, clinical spine, humerus, distal radius).

View the Comparison Table: Some Drugs for Postmenopausal Osteoporosis

The FDA has approved romosozumab-aqqg (Evenity – Amgen), a sclerostin inhibitor, for once-monthly subcutaneous (SC) treatment of osteoporosis in postmenopausal women who are at high risk for fracture (history of osteoporotic fracture or multiple risk factors for fracture) or who have failed or cannot tolerate other drugs for this indication. Romosozumab is the first sclerostin inhibitor to be approved in the US and the third drug for treatment of postmenopausal osteoporosis that stimulates bone formation; the parathyroid hormone (PTH) receptor agonists abaloparatide (Tymlos) and teriparatide (Forteo) were approved earlier. Other drugs used for treatment of postmenopausal osteoporosis, such as bisphosphonates, inhibit bone resorption and decrease bone turnover.

Diagnosis of osteoporosis is based on the results of bone mineral density (BMD) testing or by the occurrence of a fragility fracture. Bone densitometry results are generally reported in terms of standard deviations (SD) from the mean value for young adults (T-score). The World Health Organization (WHO) defines osteoporosis in women as a T-score of -2.5 or below in the spine, femoral neck, or total hip. A computerized model (FRAX) is available that estimates the 10-year probability of a hip fracture or other major osteoporotic fracture based on clinical risk factors and BMD at the femoral neck.

View the Comparison Table: Drugs for Postmenopausal Osteoporosis

The FDA has approved abaloparatide (Tymlos – Radius Health), a synthetic analog of human parathyroid hormone related peptide, for treatment of postmenopausal women with osteoporosis who are at high risk for fracture. Abaloparatide is the second parathyroid hormone receptor agonist to be approved for this indication; teriparatide (Forteo – Lilly), a recombinant parathyroid hormone analog, was the first. They are the only drugs approved for treatment of osteoporosis that stimulate bone formation. Other drugs used for this indication inhibit bone resorption.

View the Comparison Table: Drugs for Postmenopausal Osteoporosis

US guidelines for the treatment of osteoporosis have been published. The diagnosis of osteoporosis has traditionally been established by the occurrence of fragility fractures or by bone densitometry, which is generally reported in terms of standard deviations (SD) from mean values in young adults (T-score). The World Health Organization (WHO) has defined normal bone mineral density (BMD) for women as a value within one SD of the young adult mean. Values 2.5 SD or more below the mean (T-score -2.5 or below) at the spine, femoral neck, or total hip are defined as osteoporosis. The WHO has developed a computerized model (FRAX) that predicts the 10-year probability of a hip fracture or other major osteoporotic fracture based on clinical risk factors and BMD at the femoral neck.

The FDA has approved Duavee (Pfizer), a fixed-dose combination of conjugated estrogens and the new selective estrogen receptor modulator (SERM) bazedoxifene, for treatment of moderate to severe vasomotor symptoms and for prevention of osteoporosis in postmenopausal women with an intact uterus. Bazedoxifene is an estrogen agonist/antagonist with estrogen-like effects on bone and antiestrogen effects on the uterus. It is the second SERM to be approved for prevention of osteoporosis; raloxifene (Evista, and generics) has been available as a single agent for this indication since 1997.

Long-term use of bisphosphonates for prevention and treatment of osteoporosis has been associated with osteonecrosis of the jaw, atypical fractures of the femur, and possibly esophageal cancer. So for how long should patients take them?

The US Preventive Services Task Force (USPSTF) has issued a Draft Recommendation Statement saying, in effect, that community-dwelling women and men should not take calcium and vitamin D supplements for primary prevention of osteoporotic fractures because the evidence that they are helpful is insufficient and they increase the risk of kidney stones. The Medical Letter has said previously that there is no evidence that patients with an adequate intake of calcium (1000-1200 mg/day) and vitamin D (600-800 IU/day) will benefit from taking supplements.1

1. Drugs for postmenopausal osteoporosis. Treat Guidel Med Lett 2011; 9:67.

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Supplemental calcium is recommended for prevention of postmenopausal osteoporosis in women with an inadequate dietary intake of calcium. The safety of calcium supplements has recently been questioned; patients may ask if they should continue to take them. The source of this concern was the publication of 2 meta-analyses in the British Medical Journal.

The FDA has approved use of denosumab (Prolia – Amgen) for treatment of osteoporosis in postmenopausal women at high risk for fracture.

Osteoporosis is characterized by low bone mass with microarchitectural disruption and skeletal fragility that results in an increased risk of fracture. The diagnosis has traditionally been established by bone densitometry, which is generally reported in terms of standard deviations (SD) from mean values in young adults (T score). The World Health Organization (WHO) has defined normal bone mineral density (BMD) for women as a value within one SD of the young adult mean. Values 2.5 SD (T score -2.5) or more below the mean are defined as osteoporosis. The WHO has developed a computerized model (FRAX) that predicts the 10-year probability of hip fracture based on clinical risk factors and BMD at the femoral neck.

Many drugs are now marketed for treatment of postmenopausal osteoporosis, but questions remain about their use.

A 10-year study of daily oral alendronate (Fosamax) and a 7-year study of daily oral risedronate (Actonel) indicate that both drugs maintained increases in bone mineral density (BMD) and decreases in markers of bone remodeling throughout the study period. Both drugs are now more commonly taken once weekly. Available data are insufficient to compare fracture rates with alendronate and risedronate, and fracture rates are considered the most important endpoint in osteoporosis studies. Recent reports of severe pain and jaw osteonecrosis with these drugs are disturbing.

Ibandronate (Boniva - Roche/GSK), a new oral bisphosphonate, was recently approved by the FDA in a once-monthly formulation for prevention and treatment of postmenopausal osteoporosis. The drug was initially approved in 2003 as a daily tablet, but was not marketed. An intravenous formulation for use once every 3 months is under investigation.

The FDA has approved a new low-dose estrogen patch (Menostar - Berlex) for prevention of osteoporosis in postmenopausal women. Unlike other estrogen patches, it is not approved for treatment of hot flashes or other menopausal symptoms. Promotional material from the manufacturer suggests that this low dose of estrogen could prevent osteoporosis without some of the adverse effects of higher doses.

Teriparatide (ter i par' a tide; Forteo - Lilly), a recombinant segment of human parathyroid hormone, has been approved by the FDA for parenteral treatment of osteoporosis in post-menopausal women, and in men with idiopathic or hypogonadal osteoporosis, who are at high risk for fracture. Teriparatide is the first approved treatment for osteoporosis that stimulates bone formation. Other drugs approved for this indication inhibit bone resorption (Treatment Guidelines from the Medical Letter 2002;1:13).

Many drugs are now marketed for treatment of post-menopausal osteoporosis (PD Delmas, Lancet 2002; 359:2018). Prevention of this disorder has been complicated by the news that hormone replacement therapy (HRT), which many women have been taking to prevent osteoporosis, increases the incidence of coronary heart disease and that of breast cancer, stroke and pulmonary embolism as well (Medical Letter 2002; 44:78).

Once-a-week formulations of alendronate (Fosamax) in 35- and 70-mg tablets have now been approved by the FDA and are being heavily promoted for prevention and treatment of postmenopausal osteoporosis. A new formulation of risedronate (Actonel) for once-a-week use is under development and may be available next year.