What is the role of Teriparatide (parathyroid hormone-related protein) in the treatment of osteoporosis?

From the Guidelines

Teriparatide is recommended as a treatment option for patients with severe osteoporosis who are at very high risk of fracture, as it has been shown to reduce the risk of nonvertebral and morphometric vertebral fractures by 66% 1. This medication is typically administered as a 20 mcg daily subcutaneous injection for up to 24 months. It's most appropriate for patients with very low bone mineral density (T-score below -2.5), history of fragility fractures, or those who have failed or cannot tolerate other osteoporosis treatments. The medication works differently than antiresorptive drugs like bisphosphonates by stimulating new bone formation as a recombinant form of parathyroid hormone.

Some key points to consider when prescribing teriparatide include:

• Patients should be taught proper self-injection technique and need to store the pen refrigerated until first use, then at room temperature for up to 28 days.
• Common side effects include dizziness, leg cramps, and mild hypercalcemia.
• Teriparatide is contraindicated in patients with Paget's disease, unexplained elevated alkaline phosphatase, prior skeletal radiation, bone metastases, or history of bone cancer due to theoretical risk of osteosarcoma.
• After completing teriparatide therapy, patients should transition to an antiresorptive medication to maintain bone gains.
• Regular monitoring of bone mineral density and calcium levels is recommended during treatment.

According to the American College of Physicians, teriparatide may be considered for females with primary osteoporosis at very high risk of fracture, although the evidence is of low certainty 1. The European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) and the International Osteoporosis Foundation (IOF) also recommend considering teriparatide for patients at very high risk of fracture, defined as a fracture probability above the upper assessment threshold after a FRAX assessment 1.

It is essential to assess the patient's fracture risk using tools like FRAX and consider factors such as recent fracture, glucocorticoid use, and trabecular bone score to determine the best treatment approach 1. By carefully evaluating the patient's risk factors and medical history, healthcare providers can make informed decisions about the use of teriparatide and other osteoporosis treatments to reduce the risk of fractures and improve patient outcomes.

From the FDA Drug Label

Teriparatide injection is a prescription medicine used to: treat postmenopausal women who have osteoporosis who are at high risk for having broken bones (fractures) or who cannot use other osteoporosis treatments. increase the bone mass in men with primary or hypogonadal osteoporosis who are at high risk for having broken bones (fractures) or who cannot use other osteoporosis treatments treat both men and women with osteoporosis due to use of glucocorticoid medicines, such as prednisone, for several months, who are at high risk for having broken bones (fractures) or who cannot use other osteoporosis treatments.

Teriparatide is used for the treatment of osteoporosis in:

• Postmenopausal women at high risk for fracture or who have failed other osteoporosis therapies
• Men with primary or hypogonadal osteoporosis at high risk for fracture or who have failed other osteoporosis therapies
• Men and women with osteoporosis associated with sustained systemic glucocorticoid therapy at high risk for fracture or who have failed other osteoporosis therapies 2 2

From the Research

Teriparatide for Osteoporosis

• Teriparatide is an anabolic agent used for the treatment of patients with severe osteoporosis, and its effectiveness in this patient group has been studied in several clinical trials 3, 4, 5, 6, 7.
• The results of these studies show that teriparatide treatment substantially reduces the risk of vertebral fractures compared with standard care in patients with severe osteoporosis 3.
• Teriparatide has been shown to improve bone mineral density (BMD) and alter the levels of bone formation and resorption markers, with beneficial effects on vertebral fracture prevention and BMD persisting following treatment cessation 4, 5, 6.
• The most common adverse effects associated with teriparatide include injection-site pain, nausea, headaches, leg cramps, and dizziness 4, 5, 6.
• Long-term real-world, controlled studies have shown that teriparatide treatment reduces fracture prevalence to similar levels as in the general population at 10-year follow-up 7.

Efficacy of Teriparatide

• Teriparatide has been shown to be effective in reducing the risk of fractures in patients with postmenopausal osteoporosis, men with idiopathic or hypogonadal osteoporosis, and patients with glucocorticoid-induced osteoporosis 4, 5, 6.
• The annual percentage change in lumbar spine bone mineral density (BMD) was greater in the teriparatide group compared with standard care 3.
• Teriparatide treatment has been shown to increase predominantly trabecular bone in the lumbar spine and femoral neck, with less significant effects at cortical sites 5.

Safety and Tolerability

• Teriparatide is generally well tolerated, with common adverse effects including injection-site pain, nausea, headaches, leg cramps, and dizziness 4, 5, 6.
• An increased incidence of osteosarcoma in rats during preclinical trials with teriparatide led to a black box warning for the drug 6.
• Long-term safety and efficacy of teriparatide are not fully known, and clinical trials comparing teriparatide with other available agents to treat osteoporosis are needed to more clearly define its place in therapy 6.