calcium salts

calcium acetate
Calphron, Phos-Lo

calcium carbonate
Calciday-667, Cal-Plus, Caltrate 600, Os-Cal 500, Titralac, Tums 500

calcium chloride

calcium citrate
Citracal

calcium glubionate
Neo-Calglucon

calcium gluceptate

calcium gluconate

calcium lactate

calcium phosphate, tribasic
Posture

Available forms
Available by prescription only
calcium chloride
Injection: 10% solution (1 g/10 ml; each ml of solution provides 27.2 mg or 1.36 mEq of calcium) in 10-ml ampules, vials, and syringes
calcium gluceptate
Injection: 1.1 g/5 ml ampules or 5-ml vials for preparation of I.V. admixtures (each ml of solution provides 18 mg or 0.9 mEq of calcium)
calcium gluconate
Injection: 10% solution (1 g/10 ml; each ml of solution provides 9.3 mg or 0.46 mEq of calcium) in 10-ml ampules and vials, or 20-ml vials
Available without a prescription
calcium acetate
Tablets: 667 mg (169 mg of calcium)
calcium carbonate
Capsules: 125 mg (50 mg of calcium), 1.25 g (500 mg of calcium)
Oral suspension: 1.25 g (500 mg of calcium) per 5 ml
Powder: 6.5 g
Tablets: 250 mg, 650 mg, 667 mg, 1.25 g, 1.5 g
Tablets (chewable): 750 mg, 1.25 g
calcium citrate
Tablets: 950 mg (contains 200 mg of elemental calcium/g)
Tablets (effervescent): 2,376 mg (500 mg of calcium)
calcium glubionate
Syrup: 1.8 g/5 ml (contains 115 mg of elemental calcium/g)
calcium gluconate
Tablets: 500 mg, 650 mg, 975 mg, 1 g (contains 90 mg of elemental calcium/g)
calcium lactate
Tablets: 325 mg, 650 mg (contains 130 mg of elemental calcium/g)
calcium phosphate, tribasic
Tablets: 600 mg elemental calcium

Indications and dosages
 Emergency treatment of hypocalcemia.
calcium chloride
Adults: 500 mg to 1 g I.V. slowly (not to exceed 1 ml/ minute).
Children: 0.2 ml/kg I.V. slowly (not to exceed 1 ml/ minute).
calcium gluconate
Adults: 7 to 14 mEq I.V. slowly (not to exceed 0.7 to 1.8 mEq/minute).
Children: 1 to 7 mEq I.V. slowly (not to exceed 0.7 to 1.8 mEq/minute).
Repeat above dosage based on laboratory value.
 Cardiotonic use. calcium chloride Adults: 500 mg to 1 g I.V. slowly (not to exceed 1 ml/minute); or 200 to 800 mg intraventricularly as a single dose.
 Hyperkalemia. calcium gluconate Adults: 2.25 to 14 mEq I.V. slowly. Adjust administration based on ECG response.
 Hypermagnesemia.
calcium chloride Adults: 500 mg I.V. initially, repeated based on clinical response.
calcium gluceptate Adults: 2 to 5 ml I.M., or 5 to 20 ml I.V.
calcium gluconate Adults: 4.5 to 9 mEq I.V. slowly.
 During exchange transfusions.
Adults: 1.35 mEq I.V. with each 100-ml citrated blood exchange.
Neonates: 0.45 mEq I.V. after every 100 ml of citrated blood exchange.
 Hypocalcemia.
calcium acetate Adults: 2 to 4 tablets P.O. with meals.
calcium gluconate
Adults: For hypocalcemic tetany, 4.5 to 16 mEq I.V. until therapeutic response is obtained.
Children: For hypocalcemic tetany, 0.5 to 0.7 mEq/kg I.V. t.i.d. or q.i.d. or until tetany is controlled.
Neonates: 2.4 mEq/kg daily in divided doses until therapeutic response is obtained.
calcium lactate Adults: 325 mg to 1.3 g P.O. t.i.d. with meals.
 Osteoporosis prevention. Adults: 1 to 1.5 g P.O. daily of elemental calcium.
 Hyperphosphemia in end-stage renal failure. calcium acetate Adults: 2 to 4 tablets P.O. with each meal.

Pharmacodynamics
Calcium replacement: Calcium is essential for maintaining the functional integrity of the nervous, muscular, and skeletal systems and for cell membrane and capillary permeability. Calcium salts are used as a source of calcium cation to treat or prevent calcium depletion in patients for whom dietary measures are inadequate. Conditions linked to hypocalcemia are chronic diarrhea, vitamin D deficiency, steatorrhea, sprue, pregnancy and lactation, menopause, pancreatitis, renal failure, alkalosis, hyperphosphatemia, and hypoparathyroidism.

Pharmacokinetics
Absorption: Oral dose is absorbed actively in the duodenum and proximal jejunum and, to a lesser extent, in the distal part of the small intestine.
Distribution: Enters the extracellular fluid and is incorporated rapidly into skeletal tissue. Bone contains 99% of the total calcium; 1% is distributed equally between the intracellular and extracellular fluids. CSF levels are about 50% of serum calcium levels.
Metabolism: None significant.
Excretion: Excreted mainly in the feces as unabsorbed calcium that was secreted through bile and pancreatic juice into the lumen of the GI tract. Most calcium entering the kidneys is reabsorbed in the loop of Henle and the proximal and distal convoluted tubules. Only small amounts of calcium are excreted in the urine.

Contraindications and precautions
Contraindicated in patients with ventricular fibrillation, hypercalcemia, hypophosphatemia, or renal calculi. Use cautiously in digitalized patients and patients with sarcoidosis, renal or cardiac disease, cor pulmonale, respiratory acidosis, or respiratory failure.

Interactions
Drug-drug. Atenolol, fluoroquinolones, tetracyclines: Decreases bioavailability of these drugs and calcium when oral preparations are taken together. Separate administration times.
Calcium channel blockers (verapamil): Decreases calcium effectiveness. Avoid use together.
Cardiac glycosides: Increases digitalis toxicity. Administer calcium cautiously, if at all, to digitalized patients.
Phenytoin: Decreases absorption of both drugs. Avoid use together. Monitor levels closely if use together is required.
Sodium polystyrene sulfonate: Causes risk of metabolic acidosis in patients with renal disease. Avoid use together.
Thiazide diuretics: Causes risk of hypercalcemia. Avoid use together.
Drug-food. Caffeine: May affect calcium absorption. Advise patient to avoid beverages containing caffeine.
Foods containing oxalic acid (rhubarb, spinach), phytic acid (bran, whole cereals), and phosphorus (dairy products, milk): May interfere with calcium absorption. Discourage use together.
Drug-lifestyle. Alcohol use, tobacco use: May affect calcium absorption. Discourage use together.

Adverse reactions
CNS: tingling sensations, sense of oppression or heat waves, headache, irritability, weakness with I.V. use; syncope with rapid I.V. injection.
CV: mild decrease in blood pressure; vasodilation, bradycardia, arrhythmias, cardiac arrest with rapid I.V. injection.
GI: irritation, hemorrhage,constipation with oral use; chalky taste, rebound hyperacidity, nausea with I.V. use; hemorrhage, nausea, vomiting, thirst, abdominal pain with oral calcium chloride.
GU: polyuria, renal calculi.
Metabolic: hypercalcemia.
Skin: local reactions, including burning, necrosis, tissue sloughing, cellulitis, soft tissue calcification with I.M. use.
Other: pain and irritation with S.C. injection, vein irritationwith I.V. use.

Effects on lab test results
• May increase calcium levels. May decrease phosphate levels.

Overdose and treatment
Acute hypercalcemia syndrome is characterized by a markedly elevated plasma calcium level, lethargy, weakness, nausea and vomiting, and coma, and may lead to sudden death.
 In overdose, discontinue calcium immediately. After oral ingestion of calcium overdose, treatment includes removal by emesis or gastric lavage followed by supportive therapy, as needed.

Special considerations
• Give calcium chloride I.V. only.
• I.V. route is recommended in children, but not by scalp vein because calcium can cause tissue necrosis.
• Administer I.V. calcium slowly through a small-bore needle into a large vein to avoid extravasation and necrosis.
• Severe necrosis and tissue sloughing may occur after extravasation. Calcium gluconate is less irritating to veins and tissue than calcium chloride.
• After I.V. injection, patient should be recumbent for 15 minutes to prevent orthostasis.
• If perivascular infiltration occurs, discontinue I.V. immediately.
• Use I.M. route only in emergencies when no I.V. route is available. Give I.M. injections in the gluteal region in adults, lateral thigh in infants.
• Hypercalcemia may result when large doses are given to patients with chronic renal failure.
• With oral product, patient may need laxatives or stool softeners to manage constipation.
• If GI upset occurs with oral calcium, give 2 to 3 hours after meals.
• I.V. calcium may produce transient elevation of plasma 11-hydroxycorticosteroid levels (Glen-Nelson technique) and false-negative values for serum and urine magnesium as measured by the Titan yellow method.
• Monitor ECG when giving calcium I.V. Give slowly at a rate dependent on salt form used. Stop injection if patient complains of discomfort.
• Monitor serum calcium levels frequently, especially in patients with renal impairment.
• Assess Chvostek’s and Trousseau’s signs periodically to check for tetany.
Breast-feeding patients
• Calcium appears in breast milk, but not in quantities large enough to affect the breast-feeding infant.
Pediatric patients
• Administer calcium cautiously to children by I.V. route (usually not administered I.M.).
Geriatric patients
• Absorption of oral calcium may be decreased in elderly patients.

Patient education
• Tell patient not to exceed the manufacturer’s recommended dosage of calcium.
• Warn patient not to use bone meal or dolomite as a source of calcium; they may contain lead.
• Advise patient to avoid tobacco and to limit intake of alcoholic and caffeinated beverages.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use