Pharmacology · Electrolytes and rehydration solutions
Calcium chloride !
IV calcium with much more calcium per volume than calcium gluconate, but more irritating to veins. Used for acute symptomatic hypocalcaemia.
Updated 2026-11-01
Mechanism of action
Calcium chloride dissociates completely to free (ionised) calcium, the biologically active form. It restores the calcium needed for nerve conduction, muscle contraction, heart function and clotting. Because it carries much more calcium per volume than calcium gluconate, it is very irritating to tissues.
- Calcium chloride releases free calcium ions
- Ionised calcium in the blood rises
- Nerve, muscle and heart function recover
- Highly concentrated: severe tissue injury if it leaks
Pharmacokinetics
- Distribution
- Almost all body calcium is in the skeleton; about half of serum calcium is ionised and active
Indications
- Acute symptomatic hypocalcaemia in adults and children
Adverse effects
Common
- Vein irritation and pain
- Tingling, a sense of warmth and a chalky taste
- Low blood pressure and flushing with fast injection
Contraindications
- Ventricular fibrillation
- Asystole and electromechanical dissociation
- Newborns (28 days or younger) who receive or will receive IV ceftriaxone
Key interactions
- Digoxin and other cardiac glycosides
- Arrhythmias; high calcium increases digoxin toxicity
- Ceftriaxone
- Calcium-ceftriaxone precipitate; never mixed or given through the same Y-site at the same time
- Solutions containing bicarbonate or phosphate
- Precipitation in the line
What is monitored
- Serum calcium (ionised when possible)
- ECG during infusion
- Infusion site
- Kidney function
Administration and safety
- Given only IV, slowly, into a central or deep vein; never IM or subcutaneously, because it causes necrosis.
- Do not mix with other drugs in the same infusion; never mix with ceftriaxone.
- Look-alike risk: calcium chloride and calcium gluconate are not interchangeable one-for-one; check the salt and the product before giving.
- Stop at once if the site becomes painful or swollen.
Nursing care
- Before giving: serum calcium, heart rhythm and digoxin use.
- Continuous ECG monitoring during injection; report bradycardia or arrhythmias.
- Check the site often; a central line is preferred.
- Watch for signs of high calcium: nausea, confusion, weakness.
Pregnancy and breastfeeding
Data are limited; used when needed for symptomatic low calcium.
Test yourself
Think of the answer, then tap the question to see it.
How does calcium chloride differ from calcium gluconate?
It carries much more calcium per volume and is more irritating, so it is given slowly through a central or deep vein.
Why is calcium chloride never given IM?
It causes tissue necrosis and calcinosis cutis at the injection site.
Which rhythms are contraindications to calcium chloride?
Ventricular fibrillation, and asystole or electromechanical dissociation.
Related drugs
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Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: DailyMed - CALCIUM CHLORIDE injection, solution (DailyMed (U.S. National Library of Medicine), 2026); Calcium Injection: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2025); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
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