Red Flags
- Severe hypercalcaemia (corrected Ca >12 mg/dL or symptomatic) — stop calcium-based binders and active vitamin D, IV saline, consider cinacalcet/calcimimetic; admit if symptomatic[1]
- Calciphylaxis (painful necrotic skin lesions on lower abdomen, thighs, calves in dialysis patients) — emergent multidisciplinary referral; nephrology, dermatology, pain, wound care; sodium thiosulfate[1]
- PTH >9× upper limit of normal in CKD G5D unresponsive to medical therapy — parathyroidectomy evaluation[1]
- Symptomatic hyperphosphataemia with vascular calcification or pruritus — phosphate binder + dietary phosphate restriction; non-calcium binder preferred[1]
First-line treatment
Interventions
- Dietary phosphate restriction[1]Limit processed foods and additives (inorganic phosphate has high bioavailability); plant-based protein has lower phosphate absorption; renal dietitian co-management
- Treat hyperphosphataemia toward normal range[1]In CKD G3a–G5D treat overt hyperphosphataemia rather than chase any specific target; avoid hypercalcaemia and over-suppression of PTH
- Parathyroidectomy[1]CKD G3a–G5D with severe secondary or tertiary hyperparathyroidism refractory to medical therapy; subtotal or total with autotransplant; manage post-op hungry bone syndrome
First-line drug therapy
| Drug | Class | Adult | Paediatric | Notes |
|---|---|---|---|---|
| Sevelamer carbonate[1] | Non-calcium phosphate binder (anion-exchange polymer) | 800–1600 mg PO TDS with meals; titrate to phosphate | — | Preferred in vascular calcification, hypercalcaemia, or low PTH; reduces calcium load vs calcium binders |
| Lanthanum carbonate[1] | Non-calcium phosphate binder | 500–1000 mg PO TDS with meals (chew); max 3000 mg/day | — | Non-calcium binder; chewable; avoid in pregnancy; long-term tissue accumulation noted but clinical significance unclear |
| Calcium acetate or calcium carbonate[1] | Calcium-based phosphate binder | Calcium acetate 667–1334 mg PO TDS with meals; calcium carbonate 500–1500 mg PO TDS with meals | — | Restrict in adynamic bone disease, hypercalcaemia, vascular calcification; calcium acetate has lower calcium load per unit phosphate binding than carbonate |
| Calcitriol or alfacalcidol[1] | Active vitamin D / 1-alpha hydroxylated analogue | Calcitriol 0.25–0.5 µg PO daily or 1–2 µg IV thrice weekly with HD; alfacalcidol 0.25–1 µg PO daily | — | Severe and progressive secondary hyperparathyroidism in CKD G4–G5D; not routine for elevated PTH alone in G3a–G4 |
| Cinacalcet[1] | Calcimimetic (calcium-sensing receptor agonist) | 30 mg PO once daily; titrate to PTH target every 4 weeks; max 180 mg/day | — | Secondary hyperparathyroidism in CKD G5D with PTH above target despite vitamin D analogue; hypocalcaemia is dose-limiting |
| Etelcalcetide[1] | Intravenous calcimimetic | 5 mg IV at end of haemodialysis thrice weekly; titrate by 2.5–5 mg increments | — | Alternative to oral cinacalcet in HD patients with adherence concerns; hypocalcaemia and QT prolongation |
Sevelamer carbonate[1]
Non-calcium phosphate binder (anion-exchange polymer)
- Adult
- 800–1600 mg PO TDS with meals; titrate to phosphate
- Paediatric
- —
Preferred in vascular calcification, hypercalcaemia, or low PTH; reduces calcium load vs calcium binders
Lanthanum carbonate[1]
Non-calcium phosphate binder
- Adult
- 500–1000 mg PO TDS with meals (chew); max 3000 mg/day
- Paediatric
- —
Non-calcium binder; chewable; avoid in pregnancy; long-term tissue accumulation noted but clinical significance unclear
Calcium acetate or calcium carbonate[1]
Calcium-based phosphate binder
- Adult
- Calcium acetate 667–1334 mg PO TDS with meals; calcium carbonate 500–1500 mg PO TDS with meals
- Paediatric
- —
Restrict in adynamic bone disease, hypercalcaemia, vascular calcification; calcium acetate has lower calcium load per unit phosphate binding than carbonate
Calcitriol or alfacalcidol[1]
Active vitamin D / 1-alpha hydroxylated analogue
- Adult
- Calcitriol 0.25–0.5 µg PO daily or 1–2 µg IV thrice weekly with HD; alfacalcidol 0.25–1 µg PO daily
- Paediatric
- —
Severe and progressive secondary hyperparathyroidism in CKD G4–G5D; not routine for elevated PTH alone in G3a–G4
Cinacalcet[1]
Calcimimetic (calcium-sensing receptor agonist)
- Adult
- 30 mg PO once daily; titrate to PTH target every 4 weeks; max 180 mg/day
- Paediatric
- —
Secondary hyperparathyroidism in CKD G5D with PTH above target despite vitamin D analogue; hypocalcaemia is dose-limiting
Etelcalcetide[1]
Intravenous calcimimetic
- Adult
- 5 mg IV at end of haemodialysis thrice weekly; titrate by 2.5–5 mg increments
- Paediatric
- —
Alternative to oral cinacalcet in HD patients with adherence concerns; hypocalcaemia and QT prolongation
Safety-net
- Avoid over-the-counter calcium and high-dose vitamin D supplements unless prescribed — in CKD they cause hypercalcaemia and accelerate vascular calcification[1]
- Painful purple skin patches on the abdomen, thighs, or calves while on dialysis — same-day call to nephrology (concern for calciphylaxis)[1]
- Take phosphate binders with meals, not separately — they only work when bound to food phosphate in the gut[1]
Referral criteria
- Severe or symptomatic hypercalcaemia, calciphylaxis, or PTH >9× ULN despite medical therapyNephrology and consider parathyroid surgery[1]
- Persistent hyperphosphataemia despite dietary restriction and adequate dialysisNephrology with phosphate binder optimisation[1]
- Fragility fracture or DXA T-score ≤-2.5 in CKD G3a–G5DNephrology and bone-health specialist; bone biopsy may be needed before antiresorptive therapy[1]
Clinical summary
Diagnosis and management of disordered calcium, phosphate, PTH, vitamin D, and bone in CKD G3a–G5D, including dialysis vintage.