From the Guidelines
Management of patients with elevated parathyroid hormone (PTH) and hyperphosphatemia primarily focuses on controlling phosphate levels while addressing secondary hyperparathyroidism, with the most recent and highest quality study 1 suggesting a treatment approach based on serial assessments of biochemical variables. The first-line approach includes dietary phosphate restriction (800-1000 mg/day) combined with phosphate binders such as calcium-based binders (calcium carbonate 500-1500 mg with meals or calcium acetate 667 mg, 2-3 tablets with meals) or non-calcium-based options like sevelamer (800-1600 mg with meals), lanthanum carbonate (500-1000 mg with meals), or ferric citrate (1-2 tablets with meals) 1. For persistent secondary hyperparathyroidism, active vitamin D analogs are recommended, including calcitriol (0.25-1 mcg daily), paricalcitol (1-4 mcg daily), or doxercalciferol (1-5 mcg daily), but their use should be reserved for patients with severe and progressive hyperparathyroidism 1. In cases where PTH remains significantly elevated despite these measures, calcimimetics like cinacalcet (starting at 30 mg daily, titrating up to 180 mg if needed) or etelcalcetide (IV, 5-15 mg three times weekly with hemodialysis) may be added 1. Regular monitoring of calcium, phosphate, and PTH levels is essential to guide therapy adjustments and prevent complications like vascular calcification and bone disease 1. Key considerations in the management of these patients include:
- Avoiding aggressive phosphate-lowering therapy in patients not receiving dialysis, due to safety concerns 1
- Restricting the use of calcium-based phosphate binders in patients with hyperphosphatemia across the CKD spectrum 1
- Reserving the use of calcitriol and vitamin D analogues for patients with severe and progressive hyperparathyroidism 1
- Considering calcimimetics as an alternative for patients with persistent secondary hyperparathyroidism 1
From the FDA Drug Label
When dosing three times weekly, do not administer more frequently than every other day. Dose Titration Individualize the dose of paricalcitol capsules based on iPTH, serum calcium and phosphorus levels. If serum calcium is elevated, the dose should be decreased by 2 to 4 micrograms As iPTH approaches the target range, small, individualized dose adjustments may be necessary in order to achieve a stable iPTH.
The management approach for patients with elevated Parathyroid Hormone (PTH) and hyperphosphatemia involves individualizing the dose of paricalcitol capsules based on iPTH, serum calcium, and phosphorus levels. The dose should be adjusted to achieve a stable iPTH level within the target range. If serum calcium is elevated, the dose should be decreased by 2 to 4 micrograms.
- Key considerations:
- Monitor serum calcium and phosphorus levels closely after initiation of paricalcitol capsules, during dose titration periods, and during co-administration with strong CYP3A inhibitors.
- Adjust the dose based on iPTH levels, with the goal of achieving a stable iPTH level within the target range.
- Decrease the dose if serum calcium is elevated or if iPTH is persistently and abnormally low.
- Individualize the dose for each patient, taking into account their unique needs and response to treatment 2.
From the Research
Management Approach for Elevated Parathyroid Hormone (PTH) and Hyperphosphatemia
The management of patients with elevated Parathyroid Hormone (PTH) and hyperphosphatemia involves a multifaceted approach. Key considerations include:
- Reducing PTH levels to a range that supports normal bone turnover and minimizes ectopic calcification 3
- Using vitamin D analogs that inhibit PTH gene transcription and parathyroid hyperplasia, with less calcemic activity than 1,25-dihydroxyvitamin D3 3
- Employing non-calcium-based phosphate binders, such as sevelamer and lanthanum carbonate, to reduce the risk of hypercalcemia with vitamin D therapy 3
- Utilizing cinacalcet, an allosteric activator of the calcium receptor, to reduce PTH and the serum calcium-phosphate product 3
Treatment Options
Treatment options for secondary hyperparathyroidism include:
- Vitamin D analogs, such as paricalcitol and doxercalciferol, which have been shown to effectively suppress PTH levels 4, 5, 6
- Native vitamin D supplementation, which has been found to play a key role in preventing secondary hyperparathyroidism in hemodialysis patients 7
- Calcitriol, which is used to treat secondary hyperparathyroidism, but may increase the risk of hypercalcemia and hyperphosphatemia 5
- Phosphate binders, such as sevelamer and lanthanum carbonate, which help reduce serum phosphorus levels 3, 6
Comparison of Treatment Options
Studies have compared the efficacy and safety of different treatment options, including:
- Paricalcitol versus calcitriol for secondary hyperparathyroidism in stages 3-4 CKD, which found that both agents effectively suppressed PTH levels with minimal effects on serum calcium and phosphorus 5
- Paricalcitol versus doxercalciferol for secondary hyperparathyroidism in hemodialysis patients, which found that paricalcitol caused less elevation of serum phosphorus and calcium-phosphate product 6