Parathyroid Hormone

Parathyroid hormone (PTH) was approved for use in Canada in 2004 for the treatment of severe osteoporosis.

How it Works

PTH is a protein that occurs naturally in the body. It is produced by the parathyroid glands, which sit around the thyroid gland, in the neck area. PTH is important for calcium balance in the body.

Daily infusions or injections of synthetic PTH (called teriparatide or Forteo®) lead to an overall increase in bone turnover. This treatment can slow bone loss and increase bone mass by up to 20 percent in the first year of treatment. PTH is more potent than bisphosphonates and is typically prescribed for women who have had a fracture or are at high risk of having one.

Side Effects

Side effects include:

• Headache
• Dizziness
• Nausea and vomiting
• Leg cramps

Because this medication was only recently approved, its long-term effects are unknown.

In research studies, this medication was shown to cause osteosarcoma (bone cancer) in lab rats. These findings cannot predict the effects the drug will have on humans, and to date, no bone tumours have been reported in humans taking teriparatide. But because of this possible risk, teriparatide should NOT be used to prevent osteoporosis or to treat mild osteoporosis, nor should it be taken by people who can take other medications for osteoporosis. Talk to your doctor about the potential risks of taking teriparatide.

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