Not scheduled

Oral

• Capsules: 667 mg (equivalent to 169 mg elemental calcium)

• Tablets: 667 mg (some brands provide chewable form)

INDICATIONS + DOSING — FOR CLINICIAN USE ONLY

Primary Indications (Approved / Standard in India)

1. Hyperphosphataemia in Chronic Kidney Disease (CKD) — ESRD on Dialysis

ADULTS:

Parameter Recommendation

Starting dose 667–1334 mg (1–2 capsules/tablets) orally with each meal

Titration Adjust dose every 2–3 weeks based on serum phosphate levels; increase by 667 mg per meal

Usual maintenance dose 1334–2668 mg (2–4 capsules/tablets) with each meal (total: 4–8 g/day)

Maximum dose 6 g/day (limited by hypercalcaemia risk)

Clinical Notes:

• Must be administered with meals to bind dietary phosphate — no effect on empty stomach

• Target: Maintain serum phosphate within KDOQI-recommended range (3.5–5.5 mg/dL for dialysis patients)

• Monitor calcium-phosphate product (target <55 mg²/dL²) to avoid vascular calcification

• Consider transition to non-calcium binder (sevelamer, lanthanum) if persistent hypercalcaemia or adynamic bone disease

Secondary Indications – Adults (Off-label)

Indication Dose Duration Specialist Only Evidence Basis

Tumour lysis syndrome-related hyperphosphataemia — OFF-LABEL 1334–2001 mg (2–3 capsules/tablets) three times daily with meals Temporary until phosphate controlled or cytoreduction achieved Yes — Oncology/ICU settings Extrapolated from CKD use; supported by case series and clinical practice

Primary Indication: CKD-related Hyperphosphataemia

Weight-based Dosing (Children >2 years):

Parameter Recommendation

Starting dose 45 mg/kg/day elemental calcium in divided doses with meals

Titration Adjust every 2–3 weeks based on serum phosphate, calcium, and Ca×P product

Usual maintenance dose 45–70 mg/kg/day elemental calcium in divided doses with meals

Maximum dose 70 mg/kg/day elemental calcium

Practical Dosing Guide:

Body Weight Approximate Starting Dose

10–15 kg 1 capsule (667 mg) TID with meals

15–25 kg 1–2 capsules TID with meals

25–40 kg 2 capsules TID with meals

40 kg Adult dosing

Note: Calcium acetate 667 mg = 169 mg elemental calcium

Safety Monitoring:

• Serum phosphate and total calcium weekly during titration

• Monitor for constipation and ectopic calcification

• Consider non-calcium binders in children with adynamic bone disease

Secondary Indications – Paediatrics (Off-label)

Not applicable — no validated paediatric off-label indications documented in Indian practice.

⚠️ Not recommended in children <2 years of age except in exceptional circumstances under paediatric nephrology specialist supervision.

Clinical Scenario Recommendation

CKD Stages 3–5 (non-dialysis) May be used with caution; monitor for hypercalcaemia

Adynamic bone disease Initiate cautiously; consider non-calcium binders

Elevated serum calcium at baseline Avoid initiation until calcium normalised

Note: Drug is specifically indicated for use in CKD/ESRD patients; dose is titrated based on phosphate control, not renal function.

Note: Minimal hepatic metabolism; action is local in the GI tract (phosphate binding).

• Hypercalcaemia (serum calcium >10.5 mg/dL or ionised calcium above normal)

• Hypophosphataemia (serum phosphate <2.5 mg/dL)

• Severely elevated calcium-phosphate product (>55 mg²/dL²)

• Known hypersensitivity to calcium salts or formulation excipients

• Severe hypervitaminosis D

• Concurrent vitamin D or calcium supplements — increased risk of hypercalcaemia

• Digitalis (digoxin) therapy — hypercalcaemia may potentiate arrhythmic toxicity

• Patients with adynamic bone disease — calcium loading may worsen bone turnover

• Risk of vascular and soft tissue calcification with prolonged high-dose use

• Milk-alkali syndrome risk with concurrent high intake of alkali (e.g., sodium bicarbonate)

• Constipation-prone p

Parameter Recommendation

Overall safety Likely safe; low systemic absorption; limited human data in pregnancy

Preferred alternatives Sevelamer (non-calcium binder) may be preferred if hypercalcaemia risk present

When to use May be used under nephrologist supervision in pregnant ESRD patients when benefit outweighs risk

Monitoring Serum calcium and phosphate frequently; fetal growth assessment if prolonged use

Parameter Recommendation

Breastfeeding compatibility Compatible with breastfeeding

Preferred alternatives None specifically required

Expected drug levels in milk Low — minimal systemic absorption

Infant monitoring Signs of constipation or poor feeding if maternal intake is high

Parameter Recommendation

Starting dose Lower end of dosing range (667 mg / 1 capsule per meal)

Titration Slower titration recommended; increase every 3–4 weeks

Extra risks Increased risk of hypercalcaemia; soft tissue and vascular calcification; constipation; confusion (with hypercalcaemia)

Clinical note Monitor serum calcium and phosphate closely during chronic use

Interacting Drug Mechanism/Effect Recommendation

Tetracyclines (doxycycline, minocycline) Chelation → reduced antibiotic absorption Separate administration by at least 2 hours

Fluoroquinolones (ciprofloxacin, levofloxacin) Chelation → reduced antibiotic absorption Separate administration by at least 2 hours

Levothyroxine Chelation → reduced thyroxine absorption Administer levothyroxine at least 4 hours apart

Digoxin Hypercalcaemia potentiates digoxin toxicity → arrhythmias Monitor ECG and serum calcium closely; avoid hypercalcaemia

Interacting Drug Effect Recommendation

Iron supplements Reduced iron absorption due to chelation Separate administration by at least 2 hours

Vitamin D analogues (calcitriol, alfacalcidol) Increased risk of hypercalcaemia Monitor serum calcium; adjust doses accordingly

Thiazide diuretics Reduced renal calcium excretion → increased hypercalcaemia risk Monitor serum calcium

Bisphosphonates (alendronate) Reduced bisphosphonate absorption Separate by at least 2 hours

Sodium bicarbonate Risk of milk-alkali syndrome with concurrent use Avoid combination; monitor for symptoms

• Nausea

• Constipation

• Flatulence

• Abdominal discomfort

• Hypercalcaemia (dose-related)

• Metallic taste

• Hypercalcaemia crisis — may present as confusion, polyuria, nausea, cardiac arrhythmias

• Vascular and soft tissue calcification — with prolonged high-dose use

• Milk-alkali syndrome — rare; hypercalcaemia, metabolic alkalosis, and renal impairment with excessive calcium/alkali intake

• Severe constipation or bowel obstruction — rare

⚠️ Severe hypercalcaemia requires immediate dose reduction or discontinuation and supportive care.

Phase Parameters

Baseline Serum calcium, phosphate, PTH, albumin; ECG if on digitalis; calcium-phosphate product

During titration Serum phosphate and calcium weekly; adjust dose every 2–3 weeks

Long-term (stable dose) Monthly serum calcium and phosphate; Ca×P product; PTH every 1–3 months (dialysis patients)

Clinical monitoring Signs of hypercalcaemia (confusion, constipation, polyuria); vascular calcification risk assessment

• Phostat (La Renon)

• Fosbait (USV)

• RenalCal (Alniche)

• Renalzin (Alembic)

• Phoscut (Intas)

Note: Not NLEM-listed currently; not routinely supplied via public sector dialysis programmes — availability varies by state.

• Always administer calcium acetate with meals — no phosphate binding occurs on empty stomach

• Calcium acetate binds phosphate more efficiently per gram of elemental calcium compared to calcium carbonate (better phosphate binding with lower calcium load)

• Avoid concurrent use with calcium supplements or high-dose vitamin D unless strictly indicated and closely monitored

• Transition to non-calcium binders (sevelamer, lanthanum carbonate) if recurrent hypercalcaemia, elevated Ca×P product, or adynamic bone disease develops

• In paediatric patients, total calcium-alkali balance should be managed by paediatric nephrologist

• Monitor for subtle signs of calcium overload — constipation, confusion, polyuria, ECG changes

Calcium Acetate; phosphate binder; hyperphosphataemia; CKD; ESRD; dialysis; nephrology; calcium-based binder; hypercalcaemia-risk; vascular calcification

RxIndia v1.0 — 30 Jan 2026

• CDSCO product inserts

• Indian Pharmacopoeia

• NFI 2021

• API Textbook of Medicine — Nephrology chapter

• AIIMS Dialysis Unit Protocols

• Goodman & Gilman's The Pharmacological Basis of Therapeutics, 13th edition

• Indian Paediatric Nephrology Group guidelines (for paediatric phosphate management)