Bone Drugs Flashcards
What is the difference between osteoporosis and osteopenia in terms of bone mineral density (BMD) scores?
Osteoporosis is diagnosed when the BMD score is -2.5 or more below that of a healthy young adult, whereas osteopenia is diagnosed with a BMD score between -1.0 and -2.4.
What is osteoporosis, and when is therapy warranted?
Osteoporosis is the fragility of the skeleton due to the loss of bone architecture. Therapy is warranted in post-menopausal women and men aged 50 years or over who have a previous osteoporotic fracture or a bone mineral density (BMD) score of -2.5 standard deviations or more below that of a healthy young adult.
What are the first-line treatments for osteoporosis?
iThe first-line treatments include bisphosphonates, estrogens, selective estrogen receptor blockers (SERMs), Duavee, Miacalcin, Teriparatide (Fortia) , and Denosumab (Prolia). Additional treatments involve adequate dietary calcium and vitamin D, weight-bearing exercises, smoking cessation, and avoiding drugs that increase bone loss.
What is the most common cause of osteomalacia, and how is it treated?
The most common cause of osteomalacia is vitamin D deficiency. Treatment includes replenishing vitamin D with OTC D3 (starting with 800 IU daily) and daily sun exposure. In severe cases (Vitamin D levels <10), prescription vitamin D is used until levels are in the acceptable range.
What are the main drugs used in treating Paget’s disease, and what is their mechanism?
The main treatments for Paget’s disease are high-dose bisphosphonates, which decrease osteoclast activity, and calcitonin as a second-line treatment if bisphosphonates are not tolerated. Calcium carbonate with Vitamin D3 is also given daily.
What diagnostic tools are used to assess bone health in osteoporosis, and what do they measure?
DEXA scans are used to compare bone thickness to a healthy adult’s BMD, providing T and Z scores. FRAX scores help calculate the overall risk of fracture over the next 10 years, particularly useful in individuals with osteopenia to decide if treatment is needed.
What distinguishes Type I osteoporosis from Type II osteoporosis?
Type I osteoporosis is caused by bone resorption outpacing bone formation and is most common in post-menopausal women due to declining estrogen levels. Type II osteoporosis, seen in older adults, is caused by slowed bone formation
What are the common side effects of bisphosphonates, and how should they be administered?
Bisphosphonates can cause GI distress, esophagitis, osteonecrosis of the jaw, and atypical fractures with long-term use. They should be taken in the morning with water, with patients remaining upright for 30-60 minutes to avoid esophageal irritation.
Which osteoporosis drug is the only one that builds new bone, and what are its limitations?
Teriparatide (Forteo) is the only drug that builds new bone by stimulating osteoblast activity. It is a recombinant form of human parathyroid hormone and is indicated for severe osteoporosis. It is contraindicated in patients with a history of skeletal radiation and is administered via daily SC injection for up to 2 years.
What is the role of Denosumab in osteoporosis treatment, and how is it administered?
Denosumab is a monoclonal antibody that inhibits osteoclast formation, reducing fractures in post-menopausal women at high risk. Denosumab reduces the risk of vertebral, non-vertebral, and hip fractures and is administered via subcutaneous injection twice a year.
Explain the difference between osteoporosis and osteomalacia
Osteoporosis involves the fragility of the skeleton due to loss of bone architecture, while osteomalacia refers to soft or “mushy” bone where bone architecture is intact but bone strength is impaired. Osteoporosis results from bone loss, while osteomalacia is often caused by vitamin D deficiency.
What monitoring is required when treating patients with Paget’s disease??
In Paget’s disease, monitoring includes assessing levels of alkaline phosphatase, urine, and serum pyridinoline and hydroxyproline.
What is the mechanism of action of bisphosphonates in the treatment of osteoporosis?
Bisphosphonates decrease osteoclast-mediated bone resorption by binding to hydroxyapatite crystals in the bone. This results in a small but clinically significant gain in bone mass. Once bound, bisphosphonates are cleared from the bone over months to years.
What are the primary contraindications for bisphosphonates?
Bisphosphonates are contraindicated in patients with severe renal disease (GFR < 35 cc/min).
Describe the specific conditions under which teriparatide (Forteo) should be used for osteoporosis, and explain its unique mechanism of action.
Teriparatide is indicated for men and women with severe osteoporosis or those who cannot tolerate other treatments. It is the only drug that stimulates bone formation by acting as an agonist at the parathyroid hormone receptor, leading to increased osteoblastic activity, bone formation, and strength.
