Vetdrugs 2.0Calcium carbonate is an oral calcium salt used as a supplement, intestinal phosphate binder and antacid. It contains approximately 40% elemental calcium by mass, so the mass of calcium carbonate differs from the amount of calcium supplied. The relevant dosing basis depends on whether the goal is calcium replacement or binding dietary phosphorus.
Veterinary applications include selected chronic hypocalcemic disorders and hyperphosphatemia in chronic kidney disease. Its actions occur within the gastrointestinal lumen and after calcium absorption, with different therapeutic objectives for supplementation, phosphate binding and acid neutralization.
Group
Calcium supplement and phosphate binder
Mechanism of Action
In the stomach, calcium carbonate reacts with acid and releases calcium ions while neutralizing hydrogen ions. Absorbed calcium contributes to the extracellular ionized-calcium pool and to body stores, supporting neuromuscular transmission, contraction and skeletal mineral balance. Absorption depends on gastrointestinal conditions and endocrine regulation, including vitamin D activity.
Within the intestinal lumen, calcium can bind dietary phosphate to form less soluble compounds that are excreted in feces. This reduces net phosphorus absorption and can help control renal hyperphosphatemia. Binding depends on contact with dietary phosphorus rather than direct removal of circulating phosphate.
Antacid activity is a local neutralization reaction and is shorter and less comprehensive than suppression of acid secretion. The absorbed-calcium contribution remains relevant during phosphate-binding use, explaining why an effective binder can also raise calcium undesirably in some patients.
Dose Rates
Dogs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Calcium supplementation | 70–185 mg/kg | PO | Every 24 h | Total daily calcium carbonate amount; administer with food. |
| Hypoparathyroidism | Reference only | PO | Calcium carbonate 30–60 mg/kg total per day orally, divided with meals. Number of daily divisions is not specified. | |
| Phosphate binding | Reference only | PO | Calcium carbonate 60–100 mg/kg total per day orally, divided with meals. Number of daily divisions is not specified. | |
| Hypoparathyroidism | 50–75 mg/kg | PO | Every 12 h | Calcium carbonate SALT mass: two equal portions of 100–150 mg/kg total daily. Adjust with serum calcium and the vitamin D regimen. |
Cats
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Calcium supplementation | 70–185 mg/kg | PO | Every 24 h | Total daily calcium carbonate amount; administer with food. |
| Hypoparathyroidism | Reference only | PO | Calcium carbonate 30–60 mg/kg total per day orally, divided with meals. Number of daily divisions is not specified. | |
| Phosphate binding | Reference only | PO | Calcium carbonate 60–100 mg/kg total per day orally, divided with meals. Number of daily divisions is not specified. |
Indications
- Oral calcium supplementation in selected calcium-deficiency or chronic hypocalcemic states.
- Long-term management of hypoparathyroidism, often with calcitriol or another appropriate vitamin D strategy.
- Intestinal phosphate binding in dogs and cats with chronic kidney disease and persistent hyperphosphatemia.
- Selected antacid treatment of gastric hyperacidity or adjunctive management of gastrointestinal ulceration.
Contraindications
- Calcium-containing urinary calculi or hypercalcemia.
- CKD patients require careful calcium monitoring.
- Hypercalcemia; use particular caution with cardiac disease, renal disease or concurrent digitalis glycosides.
Interactions
- Binds fluoroquinolones, tetracyclines, bisphosphonates, zinc and iron.
- Thiazides increase hypercalcemia risk.
- Digitalis glycosides increase sensitivity to calcium-associated arrhythmias.
Adverse effects
- Constipation
- Bloating
- Hypercalcemia
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Calcium Carbonate 500 mg tablet | Tablet | 500 mg / tablet | PO |
| Calcium Carbonate 600 mg tablet | Tablet | 600 mg / tablet | PO |
| Calcium Carbonate 1000 mg tablet | Tablet | 1000 mg / tablet | PO |
| Calcium Carbonate 1250 mg tablet | Tablet | 1250 mg / tablet | PO |
| Calcium Carbonate 1500 mg tablet | Tablet | 1500 mg / tablet | PO |
| Titralac calcium carbonate suspension 1.25 g/5 mL | Oral Liquid | 1250 mg / 5 mL | PO |
| Calci-Mix calcium carbonate 1.25 g capsule | Capsule | 1250 mg / capsule | PO |
Monitoring and Administration
All doses here are calcium carbonate salt mass, not elemental calcium. Give with meals and adjust to calcium and phosphate results.
Pronefra is a multi-ingredient phosphate binder; the described doses are 1 mL/4.4 kg twice daily for cats and 1 mL/5 kg twice daily for dogs, with food. Its complete active composition and strengths are not supplied, so no preparation conversion is encoded.
When indicated, monitor magnesium, phosphorus, potassium, renal function and urinary calcium as well as serum calcium. Do not infer compatibility of an admixture from compatibility with a different diluent or concentration.