NATPARA is a self-administered, once-daily, subcutaneous injection into alternating thighs.1 The goal of NATPARA treatment is to achieve serum calcium within the lower half of the normal range.
Before initiating NATPARA and during treatment with NATPARA
- Confirm 25-hydroxyvitamin D stores are sufficient. If insufficient, replace to sufficient levels per standard of care
- Confirm serum calcium is above 7.5 mg/dL before starting NATPARA
Initiate NATPARA 50 mcg once daily as a subcutaneous injection in the thigh (alternate thigh every day)
In patients using active forms of vitamin D, decrease the dose of active vitamin D by 50%, if serum calcium is above 7.5 mg/dL
In patients using calcium supplements, maintain calcium supplement dose
Measure serum calcium concentration within 3 to 7 days
ADJUST VITAMIN D& CALCIUM
Adjust dose of active vitamin D or calcium supplement or both based on serum calcium value and clinical assessment (ie, signs and symptoms of hypocalcemia or hypercalcemia). Suggested adjustments to active vitamin D and calcium supplement based on serum calcium levels are shown in the table below
Repeat steps 4 and 5 until target serum calcium levels are within the lower half of the normal range, active vitamin D has been discontinued and calcium supplementation is sufficient to meet daily requirements
Active Vitamin D Forms
Above the Upper Limit of Normal (10.6 mg/dL)
Decrease or Discontinue*
Greater than 9 mg/dL and below the Upper Limit of Normal (10.6 mg/dL)
Decrease or Discontinue*
No change or decrease if active vitamin D has been discontinued
Less than or equal to 9 mg/dL and above 8 mg/dL
*Discontinue in patients receiving the lowest available dose.
- The dose of NATPARA may be increased in increments of 25 mcg every 4 weeks, up to a maximum daily dose of 100 mcg, if serum calcium cannot be maintained above 8 mg/dL without an active form of vitamin D and/or oral calcium supplementation
- The dose of NATPARA may be decreased to as low as 25 mcg per day if total serum calcium is consistently above 9 mg/dL after the active form of vitamin D has been discontinued and calcium supplement has been decreased to a dose sufficient to meet daily requirements
REMEMBER: After a NATPARA dose change, monitor clinical response as well as serum calcium. Adjust active vitamin D and calcium supplements per steps 4-6 if indicated.
The recommended NATPARA dose is the minimum dose required to prevent both hypocalcemia and hypercalciuria.
No dose adjustment is recommended in patients with mild to moderate renal or hepatic impairment.
Once a maintenance dose is achieved, regularly monitor per standard of care:
- Serum calcium
- 24-hour urinary calcium
The maintenance dose should be the lowest dose that achieves a total serum calcium (albumin-corrected) within the lower half of the normal total serum calcium range (ie, approximately 8 and 9 mg/dL), without the need for active forms of vitamin D and with calcium supplementation sufficient to meet daily requirements.
After 24 weeks, the majority of NATPARA patients had been titrated up from the starting dose of 50 mcg.
Dose distribution at end of treatment
*This dose was not part of the study.
Interruption or Discontinuation
Abrupt interruption or discontinuation of NATPARA can result in severe hypocalcemia. Resume treatment with, or increase the dose of, an active form of vitamin D and calcium supplements if indicated in patients interrupting or discontinuing NATPARA, and monitor for signs and symptoms of hypocalcemia and serum calcium levels. In the case of a missed dose, the next NATPARA dose should be administered as soon as reasonably feasible and additional exogenous calcium should be taken in the event of hypocalcemia. For full dosage and administration instructions, please see the full Prescribing Information section 2.
Reference: 1. NATPARA [package insert]. Shire-NPS Pharmaceuticals, Inc.