Teriparatide, a type of parathyroid hormone, is approved for the treatment of osteoporosis in postmenopausal women and in men who are at high risk of breaking a bone. It is also approved for the treatment of osteoporosis in men and women who are at high risk of breaking a bone as a result of taking steroid medicines for a long time. This medicine rebuilds bone and significantly increases bone mineral density. Teriparatide reduces the risk of spine and non-spine fractures.
Teriparatide is self-administered as a daily injection under the skin from a pre-loaded pen that contains a four-week supply of medicine. It can be taken for a maximum of two years. At the end of two years, bone loss can be rapid. In order to retain the benefits of treatment with teriparatide, most experts recommend that patients start an antiresorptive medicine right after finishing the teriparatide therapy.
Side effects can include leg cramps, nausea and dizziness. Modest elevations in serum and urine calcium can occur, but there is no documented increase in the risk of kidney stones.
In animal studies performed in immature rats, very high doses of teriparatide that were given for a long period of time increased the incidence of osteosarcoma, a type of bone cancer. Although common in rats, this type of tumor is extremely rare in adult humans. In the experience with teriparatide in humans, there has been no evidence to date of an increased risk of osteosarcoma.
People with certain conditions should not take this medicine. This includes people with Paget’s disease of the bone, children with growing bone, persons with unexplained alkaline phosphatase elevations (alkaline phosphatase is a specific blood test), and those who have had radiation treatment involving the skeleton. It also should not be given to people with metabolic bone diseases such as hyperparathyroidism and those with cancer that has spread to the bone. Also, people who have certain abnormal blood tests, including increased calcium levels, should not take this medicine.