Osteoporosis medications

Osteoporosis medications are medications used to treat osteoporosis, which is a condition where decreased bone strength increases the risk of a broken bone.

Osteoporosis is most commonly associated with the elderly, menopause, hyperparathyroidism, malabsorption, and with the use of some medications, like corticosteroids.

So, the underlying cause of osteoporosis is an imbalance between bone resorption and bone formation, which are normal processes of bone remodeling.

Now in bone remodeling, the process begins when osteoblasts sense micro fractures near their location.

The osteoblasts produce a substance called RANKL, or receptor activator of nuclear factor κβ ligand, which binds to RANK receptors on the surface of nearby monocytes.

RANKL induces those monocytes to fuse together to form a multinucleated osteoclast cell.

RANKL also helps the osteoclast mature and activate so that they can start resorbing bones.

The osteoclast starts secreting lysosomal enzymes, mostly collagenase, which digests the collagen protein in the organic matrix. This drills pits on the bone surface known as the Howship’s lacunae.

Osteoclasts also start producing hydrochloric acid, or HCl, which dissolves hydroxyapatite into soluble calcium – Ca2+ and phosphate – PO42- ions, and these ions get released into the bloodstream.

Moreover, osteoblasts and osteoclasts are controlled by two hormones: parathyroid hormone, which is released by parathyroid glands; and calcitonin, which is released by the thyroid gland.

At low concentrations, parathyroid hormone works by stimulating the activity of osteoblasts, thereby promoting bone formation; while at high concentrations, parathyroid hormone stimulates bone resorption.

On the other hand, calcitonin works by inhibiting osteoclast activity, thereby decreasing bone resorption.

Alright, moving on to pharmacology! Osteoporosis medications are subdivided into two main groups: non-hormonal medications, which include bisphosphonates and denosumab; and hormonal modulators, which include teriparatide, calcitonin, and raloxifene.