10% calcium gluconate solution (given intravenously) is the form of calcium most widely used in the treatment of hypocalcemia. This form of calcium is not as well absorbed as calcium lactate, and it only contains 0.93% (930 mg/dl) calcium ion (defined by 1 g weight solute dissolved in 100 ml solvent to make 1% solution w/v). Therefore, if the hypocalcaemia is acute and severe, calcium chloride is given instead.
It is also used to counteract an overdose of Epsom Salts magnesium sulfate, which is often administered to pregnant women in order to prophylactically prevent seizures (as in a patient experiencing preeclampsia). Magnesium sulfate is also given to pregnant women who are experiencing premature labor in order to slow or stop their contractions. Excess magnesium sulfate results in magnesium sulfate toxicity, which results in both respiratory depression and a loss of deep tendon reflexes (hyporeflexia). Calcium gluconate is the antidote for magnesium sulfate toxicity.
Calcium gluconate is also used as a cardioprotective agent in hyperkalemia. Though it does not have an effect on potassium levels in the blood, it reduces the excitability of cardiomyocytes thus lowering the likelihood of developing cardiac arrhythmias.
^Parham, W. A.; Mehdirad, A. A.; Biermann, K. M.; Fredman, C. S. (2006). "Hyperkalemia revisited". Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital33 (1): 40–47. PMC1413606. PMID16572868.
^Ruilope LM, Oliet A, Alcázar JM, Hernández E, Andrés A, Rodicio JL, García-Robles R, Martínez J, Lahera V, Romero JC. (December 1989). "Characterization of the renal effects of an intravenous calcium gluconate infusion in normotensive volunteers.". J Hypertens Suppl.7 (6): 170. PMID2632708.
^Bernardi M, Di Marco C, Trevisani F, Fornalè L, Andreone P, Cursaro C, Baraldini M, Ligabue A, Tamè MR, Gasbarrini G. (July 1993). "Renal sodium retention during upright posture in preascitic cirrhosis.". Gastroenterology.105 (1): 188–193. PMID8514034.
^Wong F, Massie D, Colman J, Dudley F. (March 1993). "Glomerular hyperfiltration in patients with well-compensated alcoholic cirrhosis.". Gastroenterology.104 (3): 884–900. PMID8440439.
^Lahera V, Fiksen-Olsen MJ, Romero JC. (February 1990). "Stimulation of renin release by intrarenal calcium infusion.". Hypertension15 (2): 149–152. PMID2404858.