Osteoporosis.

Osteoporosis is a common bone disease in which the bones become weak and more prone to fracture.


Diagnosis:

The diagnosis of osteoporosis is made by measuring bone mineral density (BMD) using a bone densitometry test (DXA). DXA measures BMD at the lumbar spine and hip, and is used to determine if a person has below-average bone mineral density for their age and sex. In addition to DXA, blood tests can be done to measure the levels of calcium, phosphorous, and vitamin D in the body.


Phenotypes:

Osteoporosis can present in different phenotypes, differentiated by the underlying causes and the areas of the body that are affected. Some of the more common phenotypes include:

Postmenopausal osteoporosis: This is the most common form of osteoporosis and occurs after menopause in women due to decreased estrogen levels.

Secondary osteoporosis: Occurs as a result of another disease or medical treatment, such as chronic kidney disease, rheumatoid arthritis, anorexia, or long-term use of certain medications such as corticosteroids.

Age-related osteoporosis: Occurs in men and women as they age and the body gradually loses the ability to absorb and maintain bone mineral density.

Pharmacological treatment of osteoporosis aims to reduce the risk of bone fractures and improve bone mineral density.

The main pharmacological treatment options for osteoporosis currently are:

Bisphosphonates are drugs used to inhibit bone resorption and increase bone mineral density. Bisphosphonates are administered orally or intravenously and can be taken weekly, monthly, or every three months. Some examples of bisphosphonates include alendronate, risedronate, ibandronate, and zoledronate. The most common side effects of bisphosphonates include stomach pain, nausea, headache, and muscle pain.

Selective estrogen receptor modulators (SERMs) are drugs that mimic the action of estrogen in the body and help prevent bone loss. SERMs are administered orally and can be taken daily. An example of a SERM is raloxifene. The most common side effects of SERMs include hot flashes and leg cramps.

Hormone therapy may be considered in women who have gone through menopause and is given to increase estrogen levels in the body. Hormone therapy can help prevent bone loss and reduce the risk of fractures. However, hormone therapy also has risks, such as an increased risk of blood clots and breast cancer. Therefore, hormone therapy is only recommended for women with moderate to severe menopausal symptoms and who are at low risk of complications.

Denosumab, a human monoclonal antibody administered by subcutaneous injection every six months, is licensed for the treatment of osteoporosis in postmenopausal women and in men at high risk of fractures; for the treatment of bone loss associated with hormonal withdrawal in men with prostate cancer at high risk of fractures, and for the treatment of bone loss associated with long-term systemic glucocorticoid therapy in adults at high risk of fractures.

Teriparatide is a medication that is given by daily subcutaneous injection and helps stimulate new bone formation. Teriparatide is used in patients with severe osteoporosis and a high risk of fractures.

Since 2019 Romosozumab has been available in Europe and is currently approved for the treatment of severe postmenopausal osteoporosis with a high risk of fractures.