Also Known As: Teriparatide, Forteo
Teriparatide (Forteo, Eli Lilly and Company) is a recombinant form of parathyroid hormone. It is an effective anabolic (i.e., bone growing) agent used in the treatment of some forms ofosteoporosis. It is also occasionally used off-label to speed fracture healing. Teriparatide is identical to a portion of human parathyroid hormone (PTH) and intermittent use activatesosteoblasts more than osteoclasts, which leads to an overall increase in bone.
Teriparatide is the only anabolic (i.e., bone growing) agent indicated for use in postmenopausal women with osteoporosis at a high risk for fracture or with a history of osteoporotic fracture, patients with multiple risk factors for fracture, and for patients who have failed or are intolerant to other available osteoporosis therapy. It has been FDA-approved since 2002. It is effective in growing bone (e.g., 8% increase in bone density in the spine after one year) and reducing the risk of fragility fractures. Osteoporosis medications are generally safe, but some side effects of teriparatide include headache, nausea, dizziness, and limb pain.
One randomized trial of postmenopausal women who had already fractured vertebra compared teriparatide at either 20 or 40 micrograms per day with placebo. After about 19 months, 14% of the women taking placebo had new vertebral fractures, as compared with 5% of the women taking 20 micrograms of teriparatide and 4% of the women taking 40 micrograms. There were also a statistically significant lower number of non-vertebral fractures in the teriparatide treated group. 20 micrograms of teriparatide increased spine and hip bone mineral density.
Teriparatide is also indicated to increase bone mass in men with primary or hypogonadal osteoporosis at high risk of fracture, patients with multiple risk factors for fracture, and for patients who have failed or are intolerant to other available osteoporosis therapy.
Teriparatide is indicated as well for the treatment of men and women with osteoporosis associated with sustained systemic glucocorticoidtherapy.
Teriparatide should not be prescribed for patients who are at increased risks for osteosarcoma. This includes those with Paget's Disease of bone or unexplained elevations of serum alkaline phosphate, open epiphysis, or prior radiation therapy involving the skeleton.
Teriparatide is used as off-label therapy to speed fracture repair and treat fracture nonunions. It has been reported to have been successfully used to heal fracture nonunions. Generally, due to HIPAA regulations, it is not publicized when American athletes receive this treatment to improve fracture recovery. But an Italian soccer player, Francesco Totti, was given teriparatide after a tibia/fibulafracture, and he unexpectedly recovered in time for the 2006 World Cup. It has been reported that Mark Mulder used it to recover from a hip fracture Oakland A's for the 2003 MLB playoffs and Terrell Owens to recover from an ankle fracture before the 2005 Super Bowl.
Teriparatide has a theoretical risk of osteosarcoma, which was found in rat studies but not confirmed in humans. This may be because unlike humans, rat bones grow for their entire life. The tumors found in the rat studies were located on the end of the bones which grew after the injections began. After nine years on the market, there were only two cases of osteosarcoma reported. This risk was considered by the FDA as "extremely rare" (1 in 100,000 people) and is only slightly more than the incidence in the population over 60 years old (0.4 in 100,000).