Recombinant human parathyroid hormone (rhPTH) is a biopharmaceutical drug used to treat osteoporosis, a condition characterized by weak and brittle bones. It is a recombinant form of the naturally occurring human parathyroid hormone, which is responsible for regulating calcium and phosphorus levels in the body. This drug has been approved by the US Food and Drug Administration (FDA) for the treatment of postmenopausal women with osteoporosis who are at a high risk of fracture. When taken as prescribed, rhPTH helps to increase bone density and reduce the risk of fracture. It is administered as an injection under the skin, typically once or twice a week.
Parathyroid hormone (PTH) is a naturally occurring hormone produced by the parathyroid glands in your neck. It plays a crucial role in regulating calcium and phosphorus levels in your blood. Here's a deeper look at its functions and medical applications:
Function in the Body:
- Calcium and Phosphorus Balance: PTH helps maintain the proper balance of calcium and phosphorus in your bloodstream. Calcium is essential for strong bones and teeth, muscle function, and nerve signaling. Phosphorus is also important for bone health and energy production [1].
- Bone Remodeling: PTH stimulates the release of calcium from your bones back into the bloodstream when blood calcium levels are low. It also promotes the absorption of calcium from your diet in the intestines and regulates the excretion of phosphorus by the kidneys [1].
Medical Uses:
While PTH is not directly administered as a hormone in most cases, it's involved in some medical treatments related to calcium and bone health:
- Hypoparathyroidism: This is a condition where the parathyroid glands don't produce enough PTH. In such cases, medications containing a synthetic version of PTH (recombinant human parathyroid hormone) may be prescribed to regulate calcium levels [2].
- It's important to note that a medication called calcitriol (vitamin D receptor activator) is often the first-line treatment for hypoparathyroidism, with PTH medications used in specific situations [2].
Other Considerations:
- PTH testing: Doctors may order a blood test to measure PTH levels to diagnose parathyroid disorders like hyperparathyroidism (excessive PTH production) or hypoparathyroidism [3].