side effects of intravenous Calcium gluconate:

Patients may complain of tingling sensations, a sense of oppression or heat waves and a calcium or chalky taste following the intravenous administration of calcium gluconate.

Rapid intravenous injection of calcium salts may cause vasodilation, decreased blood pressure, bradycardia, cardiac arrhythmias, syncope and cardiac arrest. Use in digitalized patients may precipitate arrhythmias.

Local necrosis and abscess formation may occur with intramuscular injection.

Intravenous administration of calcium should be avoided in patients receiving cardiac glycosides.

Calcium complexes tetracycline antibiotics rendering them inactive.