An IV form of calcium given by a healthcare provider to treat a sudden, symptomatic drop in blood calcium. It is diluted and given slowly through a secure IV line, because a fast injection can slow the heart and a leak from the vein can damage the skin.
Usually preferred over calcium chloride for peripheral IV use because it is less irritating to veins, while calcium chloride delivers about three times more elemental calcium per mL and is often chosen in cardiac arrest or through a central line. Outside this label, IV calcium is a standard antidote for magnesium sulfate toxicity and is used to stabilize the heart in severe hyperkalemia and in calcium channel blocker overdose. Oral calcium, not IV, is used for chronic replacement.
Supplies calcium. IV calcium gluconate dissociates in plasma into ionized calcium and gluconate, raising serum ionized calcium, the biologically active fraction (about 50% of total serum calcium; about 40% is protein bound, mainly to albumin). It is 100% bioavailable IV, is not metabolized, and increases urinary calcium excretion. Each mL (100 mg of calcium gluconate) provides 9.3 mg (0.465 mEq) of elemental calcium.
The label does not describe a narrow therapeutic index or direct dosing by measured blood levels of the drug. Serum calcium is monitored to adjust the infusion.
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Doses come from the FDA label. Study tool, not for clinical decisions.
Start at the lowest dose of the recommended range and monitor serum calcium every 4 hours. Prolonged use in renal impairment can let aluminum build up to toxic levels; the product contains up to 512 mcg/L.
Hepatic function does not affect how much ionized calcium becomes available after IV dosing, so dose adjustment may not be needed.
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No specific antidote. For overdose with hypercalcemia (symptoms usually appear at total calcium of 12 mg/dL or more), stop the infusion, restore intravascular volume, and promote urinary calcium excretion if needed. For extravasation or calcinosis cutis, stop IV administration at that site right away and treat as needed.
Limited data are not enough to define a drug-associated risk. Untreated maternal hypocalcemia carries its own risks: miscarriage, premature and dysfunctional labor, possibly preeclampsia, and fetal and neonatal hyperparathyroidism with bone demineralization and neonatal seizures. Watch infants of hypocalcemic mothers for signs of low or high calcium.
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Calcium is a natural part of breast milk. Whether IV calcium gluconate changes milk calcium is unknown, and there are no data on effects in the breastfed infant or on milk production. Weigh the benefits of breastfeeding against the mother's need for treatment.
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Labeled for acute symptomatic hypocalcemia in children; dosing comes from published literature and clinical experience. Neonates (1 month or younger): 100 to 200 mg/kg bolus, repeated every 6 hours if needed, or an infusion started at 17 to 33 mg/kg/hour. Older children (under 17 years): 29 to 60 mg/kg, or an infusion at 8 to 13 mg/kg/hour. Bolus no faster than 100 mg/minute. Contraindicated with ceftriaxone in neonates 28 days or younger, and premature neonates are at particular risk of aluminum toxicity.
Start at the low end of the dose range, because older adults more often have reduced liver, kidney, or heart function and other illnesses or medicines.
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