Medication Summary
The goals of pharmacotherapy are to reduce morbidity and to prevent complications. Patients with hypocalcemia due to resistance to parathyroid hormone (PTH) generally will require long-term therapy with vitamin D and calcium supplementation. Patients with hypocalcemia associated with chronic kidney disease often require phosphate binders and vitamin D supplementation.
Calcium
Class Summary
Intravenous calcium chloride or gluconate infusions restore serum calcium levels. Calcium chloride delivers 3 times more elemental calcium than calcium gluconate.
Calcium chloride
Calcium chloride moderates nerve and muscle performance by regulating the action potential excitation threshold. This form of calcium is preferred for patients in cardiac arrest and in other serious cases.. The 10% IV solution provides 100 mg/mL of calcium chloride equaling 27.2 mg/mL (1.4 mEq/mL) of elemental calcium (ie, 10 mL of calcium chloride 10% solution contains 272 mg of elemental calcium).
Calcium gluconate (Cal-GLU)
Calcium gluconate moderates nerve and muscle performance and facilitates normal cardiac function. It is the preferred form of calcium for patients not in cardiac arrest. One ampule contains 93 mg of elemental calcium. After IV treatment, calcium levels can usually be maintained with a high-calcium diet, although some patients also require oral calcium supplementation.
The oral formulation is usually used as supplementation to IV calcium therapy. Amounts of elemental calcium in calcium gluconate are as follows:
• 500-mg tablet: 45 mg
• 650-mg tablet: 58.5 mg
• 975-mg tablet: 87.75 mg
• 1-g tablet: 90 mg
Calcium carbonate (Oystercal, Caltrate, Oysco 500, Tums E-X, Children's Pepto)
Calcium carbonate is indicated to restore and maintain normocalcemia when hypocalcemia is not severe enough to warrant rapid replacement. It is used orally as supplementation to IV calcium therapy. Calcium carbonate moderates nerve and muscle performance by regulating the action potential excitation threshold. Amounts of elemental calcium in calcium carbonate tablets are as follows: Tums, 200 mg; Rolaids, 220 mg; Os-Cal, 500 mg
Calcium citrate (Calcitrate, Cal-Citrate 225, Cal-Cee)
Calcium citrate is an oral formulation usually used as supplementation to IV calcium therapy. Calcium moderates nerve and muscle performance by regulating the action potential excitation threshold and facilitating normal cardiac function. Give the amount needed to supplement dietary intake, so as to reach recommended daily amounts. The amount of elemental calcium in 1000 mg of calcium citrate is 210 mg.
Vitamin D
Class Summary
Vitamin D restores calcium levels in conditions associated with vitamin D deficiency. Vitamin D helps control hyperparathyroidism in patients with chronic renal failure and end-stage renal disease.
Calcitriol (Calcijex, Rocaltrol, Vectical)
Calcitriol increases calcium levels by promoting calcium absorption in the intestines and calcium retention in the kidneys. To prevent hyperparathyroidism, patients on dialysis may require higher doses, such as 1-2 mcg/day IV administered 2-3 times per week (approximately every other day).
Parathyroid Hormone Analogs
Class Summary
Recombinant human parathyroid hormone may be required in addition to calcium and vitamin D supplementation for hypocalcemia.
Human parathyroid hormone, recombinant (Natpara, rhPTH)
Parathyroid hormone raises serum calcium by increasing renal tubular calcium reabsorption, increasing intestinal calcium absorption, and increasing bone turnover. rhPTH is indicated as an adjunct to calcium and vitamin D to control hypocalcemia in patients with hypoparathyroidism.
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Electrocardiogram (ECG) findings in severe hypocalcemia.
