Pharmacological Management of Metabolic Bone Diseases — MCQs
Which drug decreases the bone resorption in osteoporosis?
The most important regulator of serum 1,25(OH)2 vitamin D concentration is:
Which is the drug of choice in Paget's disease?
Paget's disease is also known as -
The blood levels of 1,25 dihydroxycholecalciferol are positively regulated by:-
Which drug increases bone formation in osteoporosis?
Drug of choice for post menopausal osteoporosis is
Brittle bone disease is -
Avascular necrosis of bone is LEAST likely to be associated with?
Osteonecrosis is seen in all except
Pharmacological Management of Metabolic Bone Diseases Indian Medical PG Practice Questions and MCQs
Question 1: Which drug decreases the bone resorption in osteoporosis?
- A. Teriparatide
- B. Risedronate (Correct Answer)
- C. Cortisone
- D. Cimetidine
Explanation: ***Risedronate*** - **Risedronate** is a **bisphosphonate**, a class of drugs that inhibits osteoclast activity, thereby decreasing **bone resorption**. - By reducing the rate at which bone is broken down, it helps to preserve **bone mineral density** in patients with osteoporosis. *Teriparatide* - **Teriparatide** is a **parathyroid hormone analog** that primarily works by stimulating **osteoblast activity** to promote new bone formation. - While it treats osteoporosis, its primary mechanism is **anabolic** (bone building), not directly decreasing bone resorption as its main effect. *Cortisone* - **Cortisone** is a **glucocorticoid** that can actually *worsen* osteoporosis by increasing **bone resorption** and decreasing **bone formation** with long-term use. - It is used to treat inflammatory conditions, not to decrease bone resorption for osteoporosis. *Cimetidine* - **Cimetidine** is an **H2-receptor antagonist** used to reduce stomach acid production, commonly for conditions like GERD or ulcers. - It has no known effect on **bone metabolism** or **osteoporosis**.
Question 2: The most important regulator of serum 1,25(OH)2 vitamin D concentration is:
- A. Calcium levels in serum
- B. Magnesium levels in serum
- C. Parathyroid hormone (Correct Answer)
- D. 25-hydroxyvitamin D in serum
Explanation: ***Parathyroid hormone*** - **Parathyroid hormone (PTH)** directly stimulates the **kidney's 1-alpha hydroxylase** enzyme, which converts **25(OH)D** to its active form, **1,25(OH)2D (calcitriol)**. - This regulation is critical for maintaining **calcium and phosphate homeostasis**, with PTH levels increasing when serum calcium is low, thereby boosting 1,25(OH)2D production. *Calcium levels in serum* - While **low serum calcium** indirectly stimulates **PTH** release, which then regulates 1,25(OH)2 vitamin D, calcium itself is not the direct or most important regulator. - The direct regulatory action on the conversion enzyme is mediated by PTH. *Magnesium levels in serum* - **Magnesium** plays a cofactor role in various enzymatic reactions, including those involving vitamin D metabolism, but it is not a direct or primary regulator of **1,25(OH)2 vitamin D concentration**. - Severe **hypomagnesemia** can sometimes impair PTH secretion and action, indirectly affecting vitamin D, but this is a secondary effect. *25-hydroxyvitamin D in serum* - **25-hydroxyvitamin D** is the precursor to **1,25(OH)2 vitamin D**, and its availability limits the maximum potential production of the active form. - However, the *rate* of conversion into the active form and thus the *concentration* of 1,25(OH)2D is primarily dictated by PTH, not the precursor itself.
Question 3: Which is the drug of choice in Paget's disease?
- A. Allopurinol
- B. Calcitonin
- C. Alendronate (Correct Answer)
- D. Steroids
Explanation: ***Alendronate*** - **Bisphosphonates** like alendronate are the **first-line treatment** for Paget's disease due to their potent antiresorptive inhibitory effect on **osteoclasts**. - They reduce bone turnover, bone pain, and the risk of complications such as **fractures** and **bone deformities**. *Allopurinol* - This drug is used to treat **gout** by inhibiting **xanthine oxidase** and reducing uric acid production. - It has no role in the management of Paget's disease, which is a disorder of abnormal bone remodeling. *Calcitonin* - Historically, calcitonin was used for Paget's disease, but its effectiveness is **less than bisphosphonates** and it is associated with more side effects. - It is now generally reserved for patients who **cannot tolerate bisphosphonates** or have severe renal impairment. *Steroids* - **Corticosteroids** are potent anti-inflammatory and immunosuppressive agents. - They are primarily used in conditions like **autoimmune disorders** or severe inflammatory diseases, and are **not indicated** for the treatment of Paget's disease.
Question 4: Paget's disease is also known as -
- A. Osteitis deformans (Correct Answer)
- B. Osteochondritis
- C. Osteitis fibrosa cystica
- D. Osteomalacia
Explanation: ***Osteitis deformans*** - **Paget's disease of bone** is classically known by its historical name, **osteitis deformans**, reflecting the bone deformities observed [1]. - This chronic bone disorder is characterized by accelerated bone remodeling, resulting in enlarged and misshapen bones [1], [2]. *Osteochondritis* - This term refers to **inflammation of bone and cartilage**, often due to overuse, trauma, or ischemia. - It does not describe Paget's disease, which involves a specific disorganization of bone remodeling rather than inflammation of cartilage. *Osteitis fibrosa cystica* - This condition is a skeletal manifestation of **severe hyperparathyroidism**, characterized by bone resorption and replacement with fibrous tissue and cysts. - While it involves bone changes, its etiology and pathological process are distinct from Paget's disease. *Osteomalacia* - **Osteomalacia** is a metabolic bone disease characterized by **defective mineralization of bone osteoid** in adults, primarily due to vitamin D deficiency [3]. - It leads to soft and weak bones, which is different from the disordered but often dense bone formation seen in Paget's disease. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Bones, Joints, and Soft Tissue Tumors, pp. 1191-1194. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Osteoarticular And Connective Tissue Disease, pp. 660-661. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Osteoarticular And Connective Tissue Disease, pp. 668-669.
Question 5: The blood levels of 1,25 dihydroxycholecalciferol are positively regulated by:-
- A. 25 OH cholecalciferol
- B. Magnesium
- C. PTH (Correct Answer)
- D. Calcium
Explanation: ***PTH*** - **Parathyroid hormone (PTH)** is the primary physiological regulator of 1,25-dihydroxycholecalciferol synthesis in the kidneys. - **PTH stimulates the 1-alpha-hydroxylase enzyme**, which converts 25-hydroxycholecalciferol to the active form, 1,25-dihydroxycholecalciferol. *25 OH cholecalciferol* - This is the **precursor molecule** to 1,25-dihydroxycholecalciferol, but its blood level directly reflects overall vitamin D status rather than actively regulating the active form. - While it is the substrate for activated vitamin D, it doesn't directly stimulate its own conversion; rather, **PTH is the key regulator of the conversion process**. *Magnesium* - **Magnesium is a cofactor for many enzymatic reactions**, including those involved in vitamin D metabolism and PTH secretion. - However, it does not directly regulate the blood levels of 1,25-dihydroxycholecalciferol; severe **magnesium deficiency can impair PTH secretion** and action, indirectly affecting vitamin D. *Calcium* - **High blood calcium levels (hypercalcemia) would inhibit PTH release**, thereby negatively regulating 1,25-dihydroxycholecalciferol production. - Conversely, **low calcium levels would stimulate PTH**, which in turn increases 1,25-dihydroxycholecalciferol synthesis to raise calcium levels.
Question 6: Which drug increases bone formation in osteoporosis?
- A. Teriparatide (Correct Answer)
- B. Calcitonin
- C. Risedronate
- D. Denosumab
Explanation: ***Correct Option: Teriparatide*** - **Teriparatide** is a recombinant form of **parathyroid hormone (PTH)** that, when administered intermittently, stimulates **osteoblast activity** to increase bone formation. - It is an **anabolic agent** specifically designed to build new bone, making it unique among osteoporosis treatments that primarily inhibit bone resorption. - Administered as a **daily subcutaneous injection** for up to 2 years. *Incorrect Option: Calcitonin* - **Calcitonin** is a hormone that inhibits **osteoclast activity**, thereby reducing bone resorption, but does not directly stimulate bone formation. - It may be used for pain relief in acute vertebral fractures but has a minor role in increasing bone density. *Incorrect Option: Risedronate* - **Risedronate** is a **bisphosphonate** that works by inhibiting **osteoclast-mediated bone resorption**, preventing bone breakdown. - It does not directly promote new bone formation; its primary action is to reduce bone turnover. *Incorrect Option: Denosumab* - **Denosumab** is a **monoclonal antibody** that targets and binds to **RANKL**, thereby inhibiting **osteoclast formation, function, and survival**, leading to decreased bone resorption. - Like bisphosphonates, its main mechanism is anti-resorptive, not anabolic.
Question 7: Drug of choice for post menopausal osteoporosis is
- A. Bisphosphonates (Correct Answer)
- B. Estrogen
- C. Thyroxine
- D. Teriparatide
Explanation: ***Bisphosphonates*** - **Bisphosphonates** are considered the **first-line therapy** for established postmenopausal osteoporosis due to their proven efficacy in reducing the risk of vertebral and non-vertebral fractures. - They work by **inhibiting osteoclast activity**, thereby decreasing bone resorption and increasing bone mineral density. *Estrogen* - While **estrogen therapy** can prevent osteoporosis, it is generally not the first-line treatment due to potential risks like increased risk of **breast cancer**, **stroke**, and **venous thromboembolism**. - It is typically reserved for women with severe menopausal symptoms who also require osteoporosis prevention, and often used at the **lowest effective dose for the shortest duration**. *Thyroxine* - **Thyroxine** is a hormone used primarily to treat **hypothyroidism**, a condition where the thyroid gland doesn't produce enough thyroid hormone. - It is **not indicated for the treatment of osteoporosis** and can even worsen bone loss if given in excessive doses, leading to iatrogenic hyperthyroidism. *Teriparatide* - **Teriparatide** is an **anabolic agent** that stimulates new bone formation, making it a powerful option for severe osteoporosis or those who have failed other therapies. - However, it is an injectable medication with a **limited treatment duration** (typically 2 years) and is generally reserved for patients with a **high fracture risk** rather than being the initial drug of choice for all postmenopausal osteoporosis.
Question 8: Brittle bone disease is -
- A. Osteoporosis
- B. Pagets disease
- C. Osteopetrosis
- D. Osteogenesis imperfecta (Correct Answer)
Explanation: ***Osteogenesis imperfecta*** - **Osteogenesis imperfecta** is an inherited disorder characterized by **brittle bones** that fracture easily, due to a defect in **collagen type I** synthesis. - Patients often present with **blue sclera**, **dentinogenesis imperfecta**, and **hearing loss**, in addition to frequent fractures. *Osteoporosis* - **Osteoporosis** is a condition of **decreased bone density**, making bones fragile and prone to fracture, but it is not typically referred to as "brittle bone disease" in the same congenital sense. - It is more common in older adults and is often related to **hormonal changes** (e.g., post-menopause) or lifestyle factors. *Paget's disease* - **Paget's disease of bone** involves abnormal bone remodeling with excessive bone resorption followed by disorganized and expanded bone formation, leading to **enlarged, weakened bones**. - It typically affects older individuals and can lead to bone pain, deformities, and fractures, but it's not the primary condition associated with "brittle bone disease." *Osteopetrosis* - **Osteopetrosis** is characterized by **abnormally dense bones** due to impaired osteoclast function, leading to a buildup of bone. - While bones are dense, they are also **brittle** and prone to fracture, and the condition is also known as "marble bone disease" rather than "brittle bone disease."
Question 9: Avascular necrosis of bone is LEAST likely to be associated with?
- A. Osgood -Schlatter disease (Correct Answer)
- B. Long-term use of corticosteroids
- C. Sickle-cell disease
- D. Legg-Perthes disease
Explanation: ***Osgood-Schlatter disease*** - This condition is characterized by **inflammation of the patellar ligament** at its insertion into the tibial tuberosity, primarily due to repetitive stress in adolescents. - While it involves pain and swelling around the knee, it is a **traction apophysitis** and not a form of avascular necrosis. *Long-term use of corticosteroids* - **Corticosteroids** are a well-established risk factor for avascular necrosis, particularly in the femoral head, by affecting lipid metabolism and blood flow. - They can lead to **fat embolism** and increased intraosseous pressure, compromising blood supply to the bone. *Sickle-cell disease* - **Sickle cell disease** significantly increases the risk of avascular necrosis due to **vaso-occlusive crises**, where sickled red blood cells block small blood vessels. - This leads to **ischemia and infarction** in bone marrow, commonly affecting the femoral and humeral heads. *Legg-Perthes disease* - This is a specific type of **avascular necrosis of the femoral head** in children, causing a temporary interruption of blood supply to the epiphysis. - It results in the collapse of the femoral head and subsequent repair processes, consistent with the pathology of avascular necrosis.
Question 10: Osteonecrosis is seen in all except
- A. Fracture neck femur
- B. Paget's disease (Correct Answer)
- C. Perthe's disease
- D. Sickle cell anemia
Explanation: ***Paget's disease*** - **Paget's disease of bone (osteitis deformans)** is a localized disorder of bone remodeling, characterized by excessive and disorganized bone formation, leading to enlarged, softened, and misshapen bones, but not directly causing osteonecrosis. - While complications like **pathological fractures** and **osteosarcoma** can occur, primary osteonecrosis is not a typical feature of Paget's disease itself. *Fracture neck femur* - **Fractures of the femoral neck** can disrupt the blood supply to the femoral head, particularly the medial circumflex femoral artery, leading to **avascular necrosis** (osteonecrosis) of the femoral head. - This is a well-known and common complication, especially in displaced fractures. *Sickle cell anemia* - **Sickle cell anemia** causes sickling of red blood cells, leading to **vaso-occlusion** and impaired blood flow to bones, resulting in **bone infarcts** (osteonecrosis). - This can affect various bones, including the femoral head, humeral head, and vertebrae. *Perthe's disease* - **Perthe's disease** (Legg-Calvé-Perthes disease) is a childhood condition characterized by **idiopathic osteonecrosis** of the femoral head. - It involves the collapse and subsequent re-ossification of the femoral epiphysis due to an interruption of its blood supply.
Want unlimited practice?
Get full access to all questions, explanations, and performance tracking.
Start For Free