Calcium Chloride
Calcium chloride is a concentrated calcium salt used for selected acute situations requiring calcium replacement. A principal veterinary role is treatment of significant hypocalcemia, including supported livestock milk-fever regimens. Route and formulation are crucial because injectable calcium chloride is strongly irritating to tissues outside a suitable vein.
Calcium chloride supplies a different proportion of elemental calcium from other calcium salts. The distinction between salt mass and elemental calcium is fundamental to interpreting its formulation strength and replacement effect.
Group
Calcium supplement
Mechanism of Action
Calcium chloride dissociates to release calcium ions, increasing the circulating ionized-calcium concentration when administered intravenously. Ionized calcium is the biologically active fraction needed for neuromuscular transmission, excitation–contraction coupling, cell signaling and several enzyme and coagulation functions.
Restoring a deficient extracellular calcium pool can reverse hypocalcemia-associated weakness, tetany and impaired muscular or cardiac function. The response reflects correction of a physiologic deficit rather than a general stimulatory effect that benefits every weak or collapsed animal.
Calcium also influences the electrical threshold of excitable membranes. Its cardiac effects can be useful in selected electrolyte emergencies, but excessive or rapid exposure can itself produce rhythm disturbances. Concentration and tissue irritancy explain why extravasation can cause severe local injury and why route-specific product distinctions are clinically important.
Dose Rates
Dogs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Acute hypocalcemia | 10–30 mg/kg | IV | Calcium chloride salt basis: equivalent to 0.1–0.3 mL/kg of a 100 mg/mL solution. Administer slowly with ECG monitoring. | |
| Severe hypocalcemia | Reference only | IV | 5–15 mg/kg ELEMENTAL calcium intravenously over 10–30 minutes. Do not interpret as calcium chloride salt mass. | |
| Fixed-volume emergency calcium chloride | Reference only | IV | 10% calcium chloride 1.5–3.5 mL total IV slowly over 15 minutes, with ECG monitoring; patient size and calcium response determine selection. |
Cats
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Acute hypocalcemia | 10–30 mg/kg | IV | Calcium chloride salt basis: equivalent to 0.1–0.3 mL/kg of a 100 mg/mL solution. Administer slowly with ECG monitoring. | |
| Severe hypocalcemia | Reference only | IV | 5–15 mg/kg ELEMENTAL calcium intravenously over 10–30 minutes. Do not interpret as calcium chloride salt mass. |
Cattle
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Hypocalcemia | Reference only | IV | 2 g per 100 kg intravenously at 1 g/minute; the passage does not clearly distinguish calcium ion from salt mass. |
Horses
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Hypocalcemia | Reference only | IV | 1–2 g per adult horse intravenously slowly; elemental-versus-salt basis is not explicit. |
Indications
- Acute symptomatic or severe hypocalcemia requiring calcium replacement with an appropriate formulation.
- Selected bovine hypocalcemia or milk-fever treatment.
- Correction of documented calcium deficiency contributing to neuromuscular weakness or impaired cardiac function.
Contraindications
- Hypercalcemia.
- Use cautiously with calcium-containing urinary calculi or kidney disease.
- Intramuscular or subcutaneous administration; rapid IV bolus.
- Hypercalcemia; use particular caution with cardiac disease, renal disease or concurrent digitalis glycosides.
- Respiratory acidosis or respiratory failure requires caution because calcium chloride can acidify.
Interactions
- Oral calcium can impair absorption of iron, tetracyclines and fluoroquinolones.
- Avoid mixing injectable calcium with bicarbonate, phosphate, sulfate or tartrate solutions.
- Digitalis glycosides increase sensitivity to calcium-associated arrhythmias.
Adverse effects
- Hypercalcemia
- Constipation with oral supplementation
- Arrhythmias with rapid intravenous calcium
Toxicity
Excess calcium can cause hypercalcemia, cardiac instability and tissue mineralization.
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Calcium Chloride 100 mg/mL injection 10% calcium chloride; supplies 27.2 mg elemental calcium (1.36 mEq) per mL. Never administer intramuscularly or subcutaneously. | Injection | 100 mg / mL | IV |
Monitoring and Administration
Monitor ionized calcium and clinical response; phosphate monitoring is needed when used as a binder. Monitor heart rate and ECG during intravenous treatment.
Give intravenous calcium slowly. Avoid extravasation; injectable calcium can cause severe tissue injury. Route suitability is product-specific.
Calcium gluconate is less irritating intravenously than calcium chloride. Do not use intracardiac delivery as a routine substitute for vascular access.
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.