From the Guidelines
Parathyroid hormone replacement therapy is available for treating hypoparathyroidism, with FDA-approved medications including teriparatide (Forteo) and recombinant human parathyroid hormone (rhPTH[1-84], Natpara). The most recent and highest quality study on this topic is not directly provided in the given evidence, but based on the information available, it can be inferred that parathyroid hormone replacement is a viable treatment option for patients with hypoparathyroidism. According to 1, secondary hyperparathyroidism is a common complication of chronic kidney disease, and parathyroidectomy is a surgical treatment option. However, the evidence provided does not directly discuss parathyroid hormone replacement therapy.
In the context of hypoparathyroidism treatment, Natpara is specifically approved for hypoparathyroidism and is typically administered as a once-daily subcutaneous injection starting at 50 mcg, with dosage adjustments based on serum calcium levels. The maximum dose is 100 mcg daily, as guided by clinical practice and patient response. This therapy helps maintain normal calcium levels in patients whose parathyroid glands don't produce sufficient hormone. Traditional management of hypoparathyroidism involves calcium and vitamin D supplementation, but hormone replacement offers more physiologic regulation of calcium metabolism.
Parathyroid hormone works by increasing calcium reabsorption in the kidneys, promoting calcium release from bone, and enhancing vitamin D activation, which improves intestinal calcium absorption. Patients should be monitored regularly for serum calcium levels and potential side effects including hypercalcemia, hypocalcemia, and bone mineral density changes, as noted in general clinical guidelines 1. The choice of treatment should prioritize reducing morbidity, mortality, and improving quality of life, considering the most recent and highest quality evidence available.
Key points to consider in the treatment of hypoparathyroidism include:
- The use of parathyroid hormone replacement therapy to maintain normal calcium levels
- Regular monitoring of serum calcium levels and potential side effects
- Dosage adjustments based on patient response and serum calcium levels
- The importance of considering the most recent and highest quality evidence in treatment decisions
- Prioritizing reductions in morbidity, mortality, and improvements in quality of life.
From the FDA Drug Label
NATPARA is a prescription parathyroid hormone (PTH) used with calcium and vitamin D to control low blood calcium (hypocalcemia) in people with low PTH blood levels (hypoparathyroidism). Yes, there is a parathyroid hormone replacement, specifically NATPARA, which is a prescription parathyroid hormone (PTH) used to control low blood calcium (hypocalcemia) in people with low PTH blood levels (hypoparathyroidism) 2.
- Key points:
- NATPARA is used with calcium and vitamin D.
- It is for people with low PTH blood levels (hypoparathyroidism) who do not respond well to treatment with calcium and active forms of vitamin D alone.
- NATPARA may increase the possible risk of bone cancer (osteosarcoma).
- Administration: NATPARA is given 1 time each day in the thigh just under the skin (subcutaneous) using the Q-Cliq pen injector.
From the Research
Parathyroid Hormone Replacement Therapy
- Parathyroid hormone (PTH) replacement therapy is a treatment approach for hypoparathyroidism, a rare endocrine disease characterized by insufficient PTH secretion or action, leading to hypocalcemia 3, 4, 5, 6, 7.
- Conventional therapy for hypoparathyroidism includes calcium and active vitamin D supplementation, but it has limitations, such as fluctuations in serum calcium levels and a high pill burden, and can increase the risk of long-term complications 3, 6.
- PTH replacement therapy can effectively achieve normal serum levels of calcium, lower serum levels of phosphate, and reduce the pill burden 5, 6, 7.
- Studies have shown that PTH replacement therapy can maintain calcium levels within the normal range, while reducing the need for calcium and vitamin D supplements 3, 5, 7.
- Different forms of PTH replacement therapy have been developed, including the full-length molecule PTH(1-84) and the truncated form PTH(1-34) 3, 5, 7.
- Continuous PTH delivery by pump has been shown to increase bone turnover markers into the normal range, without overstimulation of bone turnover, and normalize renal calcium excretion 5, 7.
Benefits of PTH Replacement Therapy
- PTH replacement therapy can address aspects of hypoparathyroidism not ameliorated with conventional therapy, such as abnormal skeletal features and reduced quality of life 3, 6.
- Palopegteriparatide, a long-acting PTH analogue, has been shown to normalize urine levels of calcium and improve quality of life in comparison to conventional therapy 6.
- PTH replacement therapy can reduce the risk of long-term complications, such as ectopic calcification, nephrocalcinosis, nephrolithiasis, and renal impairment 6.
Delivery Methods
- PTH replacement therapy can be delivered through subcutaneous injections or continuous infusion by pump 5, 7.
- Pump delivery of PTH 1-34 has been shown to produce less fluctuation in serum calcium, a more than 50% reduction in urine calcium, and a 65% reduction in the PTH dose to maintain eucalcemia, compared to twice-daily injections 7.