(redirected from Dogtooth spar)
Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.

calcium carbonate

(kal-see-um kar-bo-nate) ,


(trade name),


(trade name),


(trade name),


(trade name),


(trade name),


(trade name),


(trade name),


(trade name),


(trade name),


(trade name),


(trade name),


(trade name),


(trade name),


(trade name),


(trade name),


(trade name),


(trade name),


(trade name),


(trade name),

Liquid Cal-600

(trade name),

Maalox Antacid Caplets

(trade name),


(trade name),

Mylanta Lozenges

(trade name),


(trade name),


(trade name),


(trade name),


(trade name),


(trade name),


(trade name),

Rolaids Calcium Rich

(trade name),


(trade name),

Surpass Extra Strength

(trade name),


(trade name),


(trade name),

Tums E-X

(trade name)


Therapeutic: mineral electrolyte replacements supplements
Pregnancy Category: C


Treatment and prevention of hypocalcemia.Adjunct in the prevention of postmenopausal osteoporosis.Relief of acid indigestion or heartburn.Treatment of hyperphosphatemia in end-stage renal disease.


Essential for nervous, muscular, and skeletal systems.
Maintain cell membrane and capillary permeability.
Act as an activator in the transmission of nerve impulses and contraction of cardiac, skeletal, and smooth muscle.
Essential for bone formation and blood coagulation.

Therapeutic effects

Replacement of calcium in deficiency states. Control of hyperphosphatemia in end-stage renal disease without promoting aluminum absorption.


Absorption: Absorption from the GI tract requires vitamin D.
Distribution: Readily enters extracellular fluid. Crosses the placenta and enters breast milk.
Metabolism and Excretion: Excreted mostly in the feces; 20% eliminated by the kidneys.
Half-life: Unknown.

Time/action profile (effects on serum calcium)

IVimmediateimmediate0.5–2 hr


Contraindicated in: Hypercalcemia; Renal calculi; Ventricular fibrillation.
Use Cautiously in: Patients receiving digitalis glycosides; Severe respiratory insufficiency; Renal disease; Cardiac disease.

Adverse Reactions/Side Effects

Central nervous system

  • headche
  • tingling


  • arrhythmias (most frequent)
  • bradycardia


  • constipation (most frequent)
  • nausea
  • vomiting


  • calculi
  • hypercalciuria


Drug-Drug interaction

Hypercalcemia increases the risk of digoxin toxicity.Chronic use with antacids in renal insufficiency may lead to milk-alkali syndrome.Ingestion by mouth decreases the absorption of orally administered tetracyclines, fluoroquinolones, phenytoin, and iron salts.Excessive amounts may decrease the effects of calcium channel blockers.Decreases absorption of etidronate and risedronate (do not take within 2 hr of calcium supplements).May decrease the effectiveness of atenolol.Concurrent use with diuretics (thiazide) may result in hypercalcemia.May decrease the ability of sodium polystyrene sulfonate to decrease serum potassium.Cereals, spinach, or rhubarb may decrease the absorption of calcium supplements.Calcium acetate should not be given concurrently with other calcium supplements.


1 gram of calcium carbonate contains 400 mg elemental calcium (20 mEq calcium). Doses expressed in terms of elemental calcium.
Oral (Adults) Prevention of hypocalcemia, treatment of depletion, osteoporosis—1–2 g/day in 3–4 divided doses. Antacid—0.5–1.5 g as needed. Hyperphosphatemia in end-stage renal disease —1 g with each meal, increase to 4–7 g as needed.
Oral (Children) Supplementation—45–65 mg/kg/day in 4 divided doses.
Oral (Infants) Neonatal hypocalcemia—50–150 mg/kg in 4–6 divided doses (not to exceed 1 g/day).


Tablets: 500 mg (200 mg Ca)OTC, 600 mg (240 mg Ca)OTC, 650 mg (260 mg Ca)OTC, 667 mg (266.8 mg Ca)OTC, 1 g (400 mg Ca)OTC, 1.25 g (500 mg Ca)OTC, 1.5 g (600 mg Ca)OTC
Chewable tablets: 350 mg (300 mg Ca)OTC, 420 mg (168 mg Ca)OTC, 450 mg OTC, 500 mg (200 mg Ca)OTC, 750 mg (300 mg Ca)OTC, 1 g (400 mg Ca)OTC, 1.25 g (500 mg Ca)OTC
Gum tablets: 300 mg OTC, 450 mg OTC, 500 mg (200 mg Ca)OTC
Capsules: 1.25 g (500 mg Ca)OTC
Lozenges: 600 mg (240 mg Ca)OTC
Oral suspension: 1.25 g (500 mg Ca)/5 mLOTC
Powder: 6.5 g (2400 mg Ca)/packetOTC

Nursing implications

Nursing assessment

  • Calcium Supplement/Replacement: Observe patient closely for symptoms of hypocalcemia (paresthesia, muscle twitching, laryngospasm, colic, cardiac arrhythmias, Chvostek’s or Trousseau’s sign). Notify physician or other health care professional if these occur. Protect symptomatic patients by elevating and padding siderails and keeping bed in low position.
    • Monitor patient on digitalis glycosides for signs of toxicity.
  • Antacid: When used as an antacid, assess for heartburn, indigestion, and abdominal pain. Inspect abdomen; auscultate bowel sounds.
  • Lab Test Considerations: Monitor serum calcium or ionized calcium, chloride, sodium, potassium, magnesium, albumin, and parathyroid hormone (PTH) concentrations before and periodically during therapy for treatment of hypocalcemia.
    • May cause decreased serum phosphate concentrations with excessive and prolonged use. When used to treat hyperphosphatemia in renal failure patients, monitor phosphate levels.
  • Assess patient for nausea, vomiting, anorexia, thirst, severe constipation, paralytic ileus, and bradycardia. Contact physician or other health care professional immediately if these signs of hypercalcemia occur.

Potential Nursing Diagnoses

Imbalanced nutrition: less than body requirements (Indications)
Risk for injury, related to osteoporosis or electrolyte imbalance (Indications)


  • Oral: Administer calcium carbonate 1–1.5 hr after meals and at bedtime. Chewable tablets should be well chewed before swallowing. Dissolve effervescent tablets in glass of water. Follow oral doses with a full glass of water, except when using calcium carbonate as a phosphate binder in renal dialysis. Administer on an empty stomach before meals to optimize effectiveness in patients with hyperphosphatemia.

Patient/Family Teaching

  • Instruct patient not to take enteric-coated tablets within 1 hr of calcium carbonate; this will result in premature dissolution of the tablets.
    • Do not administer concurrently with foods containing large amounts of oxalic acid (spinach, rhubarb), phytic acid (brans, cereals), or phosphorus (milk or dairy products). Administration with milk products may lead to milk-alkali syndrome (nausea, vomiting, confusion, headache). Do not take within 1–2 hr of other medications if possible.
    • Instruct patients on a regular schedule to take missed doses as soon as possible, then go back to regular schedule.
    • Advise patient that calcium carbonate may cause constipation. Review methods of preventing constipation (increasing bulk in diet, increasing fluid intake, increasing mobility) and using laxatives. Severe constipation may indicate toxicity.
    • Advise patient to avoid excessive use of tobacco or beverages containing alcohol or caffeine.
  • Calcium Supplement: Encourage patients to maintain a diet adequate in vitamin D (see ).
  • Osteoporosis: Advise patients that exercise has been found to arrest and reverse bone loss. Patient should discuss any exercise limitations with health care professional before beginning program.

Evaluation/Desired Outcomes

  • Increase in serum calcium levels.
  • Decrease in the signs and symptoms of hypocalcemia.
  • Resolution of indigestion.
  • Control of hyperphosphatemia in patients with renal failure.


A naturally occurring mineral found in several forms, for example, chalk, Iceland spar, limestone, marble.
See also: calcium carbonate.
Synonym(s): calcspar


Naturally occurring mineral used as a dental abrasive.


n an abrasive agent made from crystallized natural calcium carbonate.