Parathyroid hormone is indicated as adjunctive treatment of adult patients with chronic hypoparathyroidism who cannot be adequately controlled with standard therapy alone.
For this indication, competent medicine agencies globally authorize below treatments:
For: Adults (18-64) Elders (65+)
Subcutaneous, 50 micrograms, once daily.
1. Initiate treatment with 50 micrograms once daily as a subcutaneous injection in the thigh (alternate thigh every day). If pre-dose serum calcium is >2.25 mmol/L, a starting dose of 25 micrograms can be considered.
2. In patients using active vitamin D, decrease the dose of active vitamin D by 50%, if pre-dose serum calcium is above 1.87 mmol/L.
3. In patients using calcium supplements, maintain calcium supplement dose.
4. Measure pre-dose serum calcium concentration within 2 to 5 days. If pre-dose serum calcium is below 1.87 mmol/L or above 2.55 mmol/L, this measurement should be repeated the following day.
5. Adjust dose of active vitamin D or calcium supplement or both based on serum calcium value and clinical assessment (i.e., signs and symptoms of hypocalcaemia or hypercalcaemia). Suggested adjustments to parathyroid hormone, active vitamin D and calcium supplements based on serum calcium levels are provided below:
|Pre-dose serum |
|Adjust first||Adjust second||Adjust third|
|Parathyroid hormone||Active vitamin D|
|Above the upper limit |
of normal (ULN)
|Consider reducing or |
stopping parathyroid hormone and
re-assess by means of
2.25 mmol/L and below the upper limit of
normal (2.55 mmol/L)*
|Consider reduction||Decrease or |
|No change, or decrease|
if active vitamin D was
before this titration step
|Less than or equal to |
2.25 mmol/L and
above 2 mmol/L
|No change||No change||No change|
|Lower than 2 mmol/L||Consider increase after|
at least 2-4 weeks at a
* The value of ULN may vary by laboratory
** Discontinue in patients receiving the lowest available dose
6. Repeat steps 4 and 5 until target pre-dose serum calcium concentration is within the range of 2.0-2.25 mmol/L, active vitamin D has been discontinued and calcium supplementation is sufficient to meet daily requirements.
Serum calcium concentration must be monitored during titration.
The dose of parathyroid hormone may be increased by 25 microgram increments approximately every 2 to 4 weeks, up to a maximum daily dose of 100 micrograms. Downward titration to a minimum of 25 micrograms can occur at any time.
It is recommended to measure the albumin-corrected serum calcium 8-12 hours after dosing parathyroid hormone. If post-dose serum calcium is >ULN, then first reduce active vitamin D and calcium supplements and monitor progress. Measurements of pre- and post-dose serum calcium should be repeated and confirmed to be within an acceptable range before titration to a higher dose of parathyroid hormone is considered. If post-dose serum calcium remains >ULN, oral calcium supplementation should be further reduced or discontinued (see also adjustment table under Initiating parathyroid hormone).
At any dose level of parathyroid hormone, if post-dose albumin-corrected serum calcium exceeds the ULN and all active vitamin D and oral calcium have been withheld, or symptoms suggesting hypercalcaemia are present, the dose of parathyroid hormone should be reduced.
In the case of a missed dose, parathyroid hormone must be administered as soon as reasonably feasible and additional exogenous sources of calcium and/or active vitamin D must be taken based on symptoms of hypocalcaemia.
Abrupt interruption or discontinuation of parathyroid hormone can result in severe hypocalcaemia. Temporary or permanent discontinuation of parathyroid hormone treatment must be accompanied by monitoring of serum calcium levels and adjustment, as necessary, of exogenous calcium and/or active vitamin D.
Each dose must be administered as a subcutaneous injection once a day in alternating thighs.
It must not be administered intravenously or intramuscularly.
Liability Disclaimer : RxReasoner has utilized reasonable care in providing content and services that are accurate, complete and up to date. However, RxReasoner does not accept any responsibility or liability about it. The content and services of RxReasoner are for informational purposes only and they are not intended to be a substitute for the knowledge, expertise, skill, and judgment of physicians, pharmacists, nurses, or other healthcare professionals involved in patient care. RxReasoner offers no medical advice. Users are responsible for the use of the provided content. A shown indication or treatment should not be construed to indicate that the medication is safe, appropriate, or effective in any given patient or under any particular circumstances. The absence of an indication or treatment should not roule out the existence of other appropriate medications. Always seek the advice of a physician or other qualified health provider with any questions you may have regarding a medical condition or medicament. RxReasoner is not liable for any damages allegedly sustained arising out of the use of its content and services.