Topical treatment of osteoporosis in postmenopausal women: a specific focus on nitroglycerin ointment

The number of osteoporotic fractures is increasing worldwide and this is accompanied by increasing disability and medical costs [1,2]. Several antiresorptive treatments, including bisphosphonates, decrease bone resorption (but also decrease bone formation), and reduce the risk of vertebral fractures, which occur in 35–70% of trabecular bone. However, nonvertebral fractures that typically occur in cortical bone, including fractures of the hip, legs, upper arms and forearms account for most of the morbidity, mortality and costs owing to fractures [3] and even the most potent antiresorptive drugs reduce the risk of nonvertebral fractures by less than a third [4–9]. Furthermore, the use of bisphosphonates has been limited by concerns about potential adverse effects of longterm use, including atypical femoral fractures and osteonecrosis of the jaw. The use of estrogen for osteoporosis has been limited by concerns regarding its adverse effects on dementia, heart disease and cancer. Teriparatide is the only therapy that increases bone formation. It reduces vertebral fracture risk by approximately 70% and may decrease the risk of a subset of very ‘low trauma fractures’ by 40%. However, teriparatide also increases bone resorption, is expensive, requires daily injections and its use is limited to 24 months or less [10]. There is a worldwide need for inexpensive, easily administered treatments that increase bone strength, and substantially decrease the risk of nonvertebral as well as vertebral fracture. Nitric oxide (NO), in the form of organic nitrate may have many of these attributes.