Older osteoporosis drugs known as antiresorptives treated osteoporosis by slowing or stopping bone loss by blocking the action of osteoclasts a type of cell that removes cells from the bone. Teriparatide stimulates the formation of new bone by increasing the number and action of bone-forming cells, called osteoblasts.
In clinical studies upon which the FDA based their approval the effects of teriparatide on bone mineral density and fractures were studied in 1,637 postmenopausal women with osteoporosis who were treated for a median time of 19-months and 437 men with primary or hypogonadal osteoporosis who were treated for ten months. Patients treated with 20 mcg of teriparatide per day, along with calcium and vitamin D supplementation. Overall patients in the study showed significant increases in bone mineral density (BMD) at the spine and hip when compared to patients taking only calcium and vitamin D supplementation. The study also showed that the risk of fractures in post-menopausal women decreased 65% for spinal fractures and 53% for all other fractures caused by osteoporosis.
This drug is not without risk. During animal studies rats were found to have an increase risk of developing osteosarcoma - a rare but deadly cancer of the bone. No human subjects in the study developed osteosarcoma but the drug is not recommended for patients who are at increased risk for osteosarcoma, including patients with Paget's disease of bone or unexplained elevations of alkaline phosphatase, children or growing adults, or those who have had prior radiation therapy involving the skeleton. Additionally, patients with bone metastases or a history of skeletal malignancies, and those with metabolic bone diseases other than osteoporosis should not receive this drug. Calcium blood levels should be checked prior to prescribing and if elevated should not be prescribed as it may further increase calcium levels.
Side effects reported from the use of the drug included mild nausea, dizziness and leg cramps.
According to Beth Kitchin, R.D., of University of Alabama at Birmingham's Osteoporosis Treatment and Prevention Clinic, those with moderate to severe osteoporosis and bone loss are good candidates for the new drug. If you are being treated for osteoporosis you may want to talk with your doctor about this therapy.
