Parathyroid hormone (PTH) and its analogue, teriparatide, are a new class of osteoporosis treatments called bone formation agents. Teriparatide injection (Forteo) is the first medication approved by Health Canada in this new class.
The mechanism by which bone is constantly renewed is called bone remodelling. Teriparatide injection works in a novel way on the bone remodelling process so that new bone is generated and added to the skeleton faster than old bone is broken down. It does this by activating the osteoblast (bone-building) cells.
Teriparatide injection has been shown to increase bone density and reduce the risk of both vertebral fractures and other fractures associated with osteoporosis.
It is used for the treatment of postmenopausal women with severe osteoporosis who are at high risk of fracture or who have failed or are intolerant to previous osteoporosis therapy. It is also used to increase bone mass in men with primary or hypogonadal (low testosterone) severe osteoporosis who have failed or are intolerant to previous osteoporosis therapy. It is also indicated for the treatment of osteoporosis associated with sustained systemic glucocorticoid therapy in men and women who are at increased risk of fracture.
It is taken as a sub-cutaneous injection into the thigh or abdominal wall, 20 mcg (micrograms) once a day. This medication should not be taken for longer than 24 months.
Possible side effects include dizziness, nausea and leg cramps.