Which of the following drugs used in osteoporosis acts both by decreasing the resorption of bone as well as inducing new bone formation?
**Core Concept**
The management of osteoporosis involves the use of medications that can either decrease bone resorption or increase bone formation. **Osteoporosis** is characterized by a decrease in bone mass and density, leading to an increased risk of fractures. **Bone remodeling** is a continuous process that involves the resorption of bone by **osteoclasts** and the formation of new bone by **osteoblasts**.
**Why the Correct Answer is Right**
The correct answer is a drug that has a dual mechanism of action, both decreasing the resorption of bone and inducing new bone formation. This is typically seen with **teriparatide**, a recombinant form of **parathyroid hormone (PTH)**, which stimulates **osteoblasts** to form new bone and also has some effect on reducing **osteoclast** activity.
**Why Each Wrong Option is Incorrect**
**Option A:** Might be a **bisphosphonate**, which primarily acts by inhibiting **osteoclast** activity, thus reducing bone resorption but not significantly inducing new bone formation.
**Option B:** Could be **denosumab**, a **RANKL inhibitor** that decreases bone resorption but does not induce new bone formation.
**Option D:** Might be **calcitonin**, which also reduces bone resorption but does not have a significant effect on new bone formation.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that while many drugs used in osteoporosis can decrease bone resorption, few have the ability to induce significant new bone formation, making **teriparatide** and possibly **abalooparatide** (another PTH-related drug) unique in their mechanism of action.
**Correct Answer:** D. Teriparatide.