TREATMENT APROACH OF HYPERPARATHYROIDISM

Both Cin & Etlc classes lower PTH levels but have disparate effects on Ca+ & PO4 levels; thus, we choose different ttt approaches based on SPO4 & Ca+

 

Parathyroid adenoma

List of abbreviations:

1)     Calt: Calcitriol

2)    Cin: Cinacalcet.

3)    Etlc: Etelcalcetide.

4)      Cmm: Calcimimetics

5)      PTH: Parathyroid hormone

6)      Hpr: hyperparathyroidism

 

TREATMENT APROACH OF HYPERPARATHYROIDISM

 

Both Cin & Etlc classes lower PTH levels but have disparate effects on Ca+ & PO⁴ levels; thus, we choose different ttt approaches based on SPO⁴ & Ca+ levels. The optimal approach for management of hyperparathyroidism is greatly consistent with the 2017 KDIGO guidelines as follows:

 

1)    Ptns with phosphate <5.5 mg/dL (<1.78 mmol/L) & Ca+ <9.5 mg/dL (<2.37 mmol/L) can be ttt with Calt monotherapy. However, other vit D analogs are also efficacious in PTH reduction.

2)    Some physicians suggest such ptns ttt with Cmm rather than Calt or a synthetic vit D analog, despite of lacking evidence of any survival benefits for Cmm.   

3)    Cin should NOT be used if Ca+ level is <8.4 mg/dL (<2.1 mmol/L), since it induces hypo- Ca+. Such ptns could be ttt with Calt.

4)    Dose plan is empirical, with the target of higher doses of Calt or synthetic vit D analogs to reach a target plasma PTH level & maintain S PO⁴≤5.5 mg/dL.

5)    Concurrent means to maintain goal S.PO⁴ are applied.

6)    Ptns with inadequate decline of PTH on Calt, we can add Cin, providing the ca is >8.4 mg/dL. Almost 50% of ptns with severe Hpr may exhibit little or No lowering in pl PTH with Calt therapy.

7)    The addition of Cin may augment the chance to achieve PTH target value and permit lowering the doses of vit D analog, that is less likely to induce hyper-Ca+  or hyper-PO⁴.

8)    Cin can be initiated at 30 mg/d. orally, with stepwise increments to 60, 90, & 180 mg/d. Dose changes can be proceeded every 4 wk until target is achieved.

9)    Ptns with s PO⁴ ≥ 5.5 mg/dL (≥1.78 mmol/L) or S.Ca+ ≥9.5 mg/dL (≥2.37 mmol/L) & persistently high PTH, despite maximal efforts to decline PO⁴, initiate Cmm rather than Calt or a synthetic vit D analog.

10) Calcitriol & synthetic vit D analogs should NOT be used in such ptns at least initially, as they both elevate S.Ca+ & PO⁴.

11) Cin should not be initiated if S Ca+ is <8.4 mg/dL (<2.1 mmol/L), as it induces Ca+ decline.

12) Maintain s levels of corrected total Ca+ between 8.4 & 9.5 mg/dL (2.10-2.37 mmol/L).

13) Ptns who do Not have enough PTH reduction with Cin alone, we can add Calt or a synthetic vit D analog, providing the phosphate <5.5 mg/dL (<1.78 mmol/L) & Ca+ <9.5 mg/dL (<2.37 mmol/L).

14) Etelcalcetide (Etlc): Etlc was superior to Cin in decreasing PTH by > 30 %. Nausea & vomiting were comparable. However, hypocalcemia was more evident in Etlc g requiring increasing S.Ca⁺ via:

1.    Increasing dialysate Ca.

2.    Giving Ca-containing PO⁴ binders,

3.    Oral Ca+ supplements, Calt and active vit D).

-Etlc therapy > may prolong QT interval in many ptns. However, as it’s provided IV, its compliance is not certain.

 See also: https://draft.blogger.com/u/0/blog/post/edit/8610857019469578230/4671430952962116941