What is Synthetic Parathyroid Hormone (PTH)?

From the Guidelines

Synthetic parathyroid hormone (PTH) medications, such as teriparatide, should be used with caution in patients with osteoporosis, due to the potential risk of osteosarcoma, and are contraindicated in patients with bone cancer risk factors, Paget's disease, unexplained alkaline phosphatase elevations, prior skeletal radiation, or growing skeletons, as stated in the study by 1.

Key Points to Consider

• Synthetic PTH medications, including teriparatide and abaloparatide, are effective treatments for osteoporosis, stimulating new bone formation by activating osteoblasts, as noted in the study by 1.
• These medications are typically administered as daily subcutaneous injections, with teriparatide given at a dose of 20mcg and abaloparatide at a dose of 80mcg, for up to 24 months, as stated in the study by 1.
• The American College of Physicians (ACP) reaffirms the recommendations for the pharmacologic treatment of primary osteoporosis or low bone mass to prevent fractures in adults, which includes the use of synthetic PTH medications, as noted in the study by 1.

Potential Risks and Side Effects

• Synthetic PTH medications carry black box warnings for potential osteosarcoma risk, and are contraindicated in patients with certain risk factors, as stated in the study by 1.
• Common side effects include hypercalcemia, hypercalciuria, nausea, and orthostatic hypotension, as noted in the study by 1.
• Regular monitoring of calcium levels is essential, especially when initiating therapy or adjusting doses, as stated in the study by 1.

Clinical Guidelines and Recommendations

• The ACP Clinical Guidelines Committee decided that an update of the living systematic review is not warranted at this time, taking into consideration the lack of a signal of any conclusion changing evidence on benefits or harms from the new evidence identified in the surveillance search, as noted in the study by 1.
• The ACP reaffirms the recommendations in the living clinical guideline on pharmacologic treatment of primary osteoporosis or low bone mass to prevent fractures in adults, which includes the use of synthetic PTH medications, as stated in the study by 1.

From the FDA Drug Label

Teriparatide injection is a recombinant human parathyroid hormone analog (PTH 1-34) It has an identical sequence to the 34 N‑terminal amino acids (the biologically active region) of the 84-amino acid human parathyroid hormone. The answer is: Synthetic PTH, also known as teriparatide, is a recombinant human parathyroid hormone analog (PTH 1-34) 2.

• Key characteristics:
  • Identical sequence to the 34 N‑terminal amino acids of human parathyroid hormone
  • Recombinant human parathyroid hormone analog (PTH 1-34)
  • Manufactured using a strain of Pseudomonas fluorescens modified by recombinant DNA technology

From the Research

Synthetic PTH Overview

• Synthetic PTH, also known as teriparatide, is a genetically engineered analog of human parathyroid hormone used in the treatment of osteoporosis 3, 4, 5.
• It acts as an anabolic drug by increasing activity in both osteoblasts and osteoclasts, resulting in a net increase of bone formation 4, 5.

Clinical Applications

• Teriparatide is recommended for use in post-menopausal women, men with hypogonadal osteoporosis, and men and women with glucocorticoid-induced osteoporosis 3, 4.
• It has been shown to reduce the risk of vertebral and non-vertebral fractures in postmenopausal osteoporotic women 3, 5.
• Teriparatide may also be considered in patients with severe osteoporosis who have failed to respond to other treatments, such as bisphosphonates 4.

Treatment Guidelines

• Teriparatide should be used in combination with calcium and vitamin D supplements 3, 5.
• The treatment duration should not exceed 2 years, due to the risk of osteosarcoma in animal studies 3, 5.
• Monitoring of serum calcium levels is recommended, and mild hypercalcemia can be treated by adjusting the dosage or withdrawing calcium supplements 3.

Comparison with Other Treatments

• Teriparatide has been shown to have a more pronounced effect on bone mineral density compared to alendronate 5.
• The combination of teriparatide and antiresorptive medications, such as denosumab, may provide maximal benefit in osteoporosis treatment 6.

Additional Uses

• Teriparatide has been used to treat severe hypocalcemia after kidney transplantation in parathyroidectomized patients, with promising results 7.