From the Guidelines
Hypocalcemia should be treated with calcium replacement when serum levels of corrected total calcium are low, as chronic lower levels can cause secondary hyperparathyroidism, adverse effects on bone mineralization, and increased mortality. According to the K/DOQI clinical practice guidelines for bone metabolism and disease in chronic kidney disease 1, it is essential to maintain normal serum levels of corrected total calcium in patients with chronic kidney disease (CKD).
When considering calcium replacement, several factors should be taken into account:
- The patient's serum calcium levels, with treatment initiated when levels are low
- The presence of conditions that affect calcium absorption, such as vitamin D deficiency, hypoparathyroidism, or CKD
- The use of medications that deplete calcium, such as certain diuretics
- The risk of hypercalcemia and soft-tissue calcification, particularly in patients with CKD
For mild hypocalcemia, oral calcium supplements such as calcium carbonate or calcium citrate may be recommended, typically taken 2-3 times daily with meals for better absorption. The total daily supplementation should generally not exceed 2,000mg. It is crucial to avoid high calcium intake, as this can lead to hypercalcemia and/or soft-tissue calcification, particularly in patients with CKD. In cases of severe hypocalcemia, intravenous calcium gluconate may be administered in hospital settings. Calcium supplements should be taken separately from certain medications that can interfere with absorption, such as tetracycline antibiotics and thyroid medications. If symptoms of low calcium occur, such as tingling, muscle cramps, or irregular heartbeat, medical attention should be sought promptly.
From the FDA Drug Label
The usual adult dosage in hypocalcemic disorders ranges from 200 mg to 1 g (2 -10 mL) at intervals of 1 to 3 days depending on the response of the patient and/or results of serum ionized calcium determinations. Repeated injections may be required because of rapid excretion of calcium. Ionized calcium concentrations should be measured, to assist in dosage adjustment
The decision to replace calcium in cases of hypocalcemia should be based on the patient's response and/or serum ionized calcium determinations. Repeated injections may be required every 1 to 3 days, or even more frequently (e.g., q 4 to 6 hours in pediatric patients), due to rapid excretion of calcium 2.
- Key factors to consider when deciding to replace calcium include:
- Patient's response to treatment
- Results of serum ionized calcium determinations
- Frequency of injections (e.g., every 1 to 3 days, or more frequently in pediatric patients)
- Dosage adjustment should be guided by ionized calcium concentrations.