From the FDA Drug Label
2 DOSAGE & ADMINISTRATION 2.1 Important Administration Instructions Calcium Gluconate Injection contains 100 mg of calcium gluconate per mL which contains 9.3 mg (i.e., 0.465 mEq) of elemental calcium.
The FDA drug label does not answer the question.
From the Research
Calcium replacement via intravenous (IV) route should be administered when rapid correction of hypocalcemia is needed, with the most recent and highest quality study suggesting the use of 4g of calcium gluconate for moderate to severe hypocalcemia 1. When replacing calcium IV, it is essential to consider the severity of hypocalcemia and the patient's clinical presentation.
- For acute symptomatic hypocalcemia, the dose of calcium gluconate can range from 1-4 grams, depending on the severity of hypocalcemia, with 4g being the most effective dose for moderate to severe cases 1.
- The calcium gluconate should be infused at a rate of 1g/h in a small-volume admixture, with serum ionized calcium levels monitored regularly to avoid hypercalcemia 1.
- Calcium chloride provides more elemental calcium but is more irritating to veins and should be given through a central line 2.
- During administration, it is crucial to monitor serum calcium levels every 4-6 hours, watch for signs of hypercalcemia, and ensure the IV site remains patent as extravasation can cause tissue necrosis.
- The underlying cause of hypocalcemia should be addressed simultaneously, and transition to oral calcium supplements should be initiated as soon as the patient is stable and able to take oral medications 3.
- IV calcium replacement is particularly important in cases of severe hypocalcemia with tetany, seizures, QT prolongation, or hypotension. The most recent study on the management of hypocalcemia suggests that oral calcium and/or vitamin D supplementation is the most frequently used treatment for chronic hypocalcemia, while intravenous calcium infusion is essential for acute cases 3.