Calcium carbonate

Calcium carbonate
Adult Indications & Dosage
Pediatric Indications & Dosage
Contraindications
Warnings & Precautions
Adverse Reactions
Drug Interactions
Use in Specific Populations
Administration & Monitoring
Overdosage
Pharmacology
Clinical Studies
How Supplied
Images
Patient Counseling Information
Precautions with Alcohol
Brand Names
Look-Alike Names

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Kiran Singh, M.D. [2]

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Overview

Calcium carbonate is an antacid that is FDA approved for the treatment of heartburn, sour stomach, acid indigestion, upset stomach associated with these symptoms. Common adverse reactions include constipation, flatulence, swollen abdomen.

Adult Indications and Dosage

FDA-Labeled Indications and Dosage (Adult)

Indications

• Calcium deficiency; Prophylaxis

Dosage

• Calcium deficiency; Prophylaxis: 19 to 50 years, RDA is 1000 mg elemental calcium per day in divided doses of 500 mg or less each; max 2500 mg per day.

• Calcium deficiency; Prophylaxis: 51 to 70 years (men), RDA is 1000 mg elemental calcium per day in divided doses of 500 mg or less each; max 2000 mg per day.

• Calcium deficiency; Prophylaxis: 51 to 70 years (women), RDA is 1200 mg elemental calcium per day in divided doses of 500 mg or less each; max 2000 mg per day.

Calcium deficiency; Prophylaxis: greater than 70 years, RDA is 1200 mg elemental calcium per day in divided doses of 500 mg or less each; max 2000 mg per day.

Off-Label Use and Dosage (Adult)

Guideline-Supported Use

There is limited information regarding Off-Label Guideline-Supported Use of Calcium carbonate in adult patients.

Non–Guideline-Supported Use

Indications

• Chemical burn, Hydrofluoric acid
• Fracture of bone; Prophylaxis
• Heartburn
• Hypocalcemia, Chronic
• Postmenopausal osteoporosis

Pediatric Indications and Dosage

FDA-Labeled Indications and Dosage (Pediatric)

Indications

Calcium deficiency; Prophylaxis

Dosage

• Calcium deficiency; Prophylaxis: 0 to 6 months, RDA is 200 mg elemental calcium per day; max 1000 mg per day.

• Calcium deficiency; Prophylaxis: 6 to 12 months, RDA is 260 mg elemental calcium per day; max 1500 mg per day.

• Calcium deficiency; Prophylaxis: 1 to 3 years, RDA is 700 mg elemental calcium per day; max 2500 mg per day.

• Calcium deficiency; Prophylaxis: 4 to 8 years, RDA is 1000 mg elemental calcium per day; max 2500 mg per day.

• Calcium deficiency; Prophylaxis: 9 to 13 years, RDA is 1300 mg elemental calcium per day; max 3000 mg per day.

Calcium deficiency; Prophylaxis: 14 to 18 years, RDA is 1300 mg elemental calcium per day; max 3000 mg per day.

Off-Label Use and Dosage (Pediatric)

Guideline-Supported Use

There is limited information regarding Off-Label Guideline-Supported Use of Calcium carbonate in adult patients.

Non–Guideline-Supported Use

Indications

• Heartburn

Contraindications

There is limited information regarding Calcium carbonate Contraindications in the drug label.

Warnings

Ask a doctor before use if you have

• Kidney stones
• A calcium-restricted diet

Ask a doctor or pharmacist before use if you are

• Now taking a prescription drug. Antacids may interact with certain prescription drugs.

When using this product

• Do not take more than 10 tablets in 24 hours
• Do not use the maximum dosage for more than 2 weeks

Keep out of reach of children.

Adverse Reactions

Clinical Trials Experience

Common

Gastrointestinal:

• Constipation
• Flatulence
• Swollen abdomen

Serious

Cardiovascular

• Myocardial infarction

Renal

• Urolithiasis

Reproductive

• Prostate cancer

Other

• Milk alkali syndrome

Postmarketing Experience

There is limited information regarding Calcium carbonate Postmarketing Experience in the drug label.

Drug Interactions

There is limited information regarding Calcium carbonate Drug Interactions in the drug label.

Use in Specific Populations

Pregnancy

Pregnancy Category (FDA): There is no FDA guidance on usage of Calcium carbonate in women who are pregnant.
Pregnancy Category (AUS): There is no Australian Drug Evaluation Committee (ADEC) guidance on usage of Calcium carbonate in women who are pregnant.

Labor and Delivery

There is no FDA guidance on use of Calcium carbonate during labor and delivery.

Nursing Mothers

There is no FDA guidance on the use of Calcium carbonate in women who are nursing.

Pediatric Use

There is no FDA guidance on the use of Calcium carbonate in pediatric settings.

Geriatic Use

There is no FDA guidance on the use of Calcium carbonate in geriatric settings.

Gender

There is no FDA guidance on the use of Calcium carbonate with respect to specific gender populations.

Race

There is no FDA guidance on the use of Calcium carbonate with respect to specific racial populations.

Renal Impairment

There is no FDA guidance on the use of Calcium carbonate in patients with renal impairment.

Hepatic Impairment

There is no FDA guidance on the use of Calcium carbonate in patients with hepatic impairment.

Females of Reproductive Potential and Males

There is no FDA guidance on the use of Calcium carbonate in women of reproductive potentials and males.

Immunocompromised Patients

There is no FDA guidance one the use of Calcium carbonate in patients who are immunocompromised.

Administration and Monitoring

Administration

• Oral

Monitoring

There is limited information regarding Calcium carbonate Monitoring in the drug label.

IV Compatibility

There is limited information regarding the compatibility of Calcium carbonate and IV administrations.

Overdosage

There is limited information regarding Calcium carbonate overdosage. If you suspect drug poisoning or overdose, please contact the National Poison Help hotline (1-800-222-1222) immediately.

Pharmacology

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Template:Chembox header2 | Calcium carbonate
Identifiers
CAS Number	471-34-1 Y
3D model (JSmol)	Interactive image Interactive image
ChEBI	CHEBI:3311 Y
ChEMBL	ChEMBL1200539 N
ChemSpider	9708 Y
ECHA InfoCard
KEGG	D00932 Y
PubChem CID	10112
UNII	H0G9379FGK Y
InChI InChI=1S/CH2O3.Ca/c2-1(3)4;/h(H2,2,3,4);/q;+2/p-2 Y Key: VTYYLEPIZMXCLO-UHFFFAOYSA-L Y InChI=1/CH2O3.Ca/c2-1(3)4;/h(H2,2,3,4);/q;+2/p-2 Key: VTYYLEPIZMXCLO-NUQVWONBAS
SMILES [Ca+2].[O-]C([O-])=O C(=O)([O-])[O-].[Ca+2]
Properties
Chemical formula	CaCO3
Molar mass	100.0869 g/mol
Hazards
Related compounds
Template:Chembox header2 | Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Mechanism of Action

There is limited information regarding Calcium carbonate Mechanism of Action in the drug label.

Structure

There is limited information regarding Calcium carbonate Structure in the drug label.

Pharmacodynamics

There is limited information regarding Calcium carbonate Pharmacodynamics in the drug label.

Pharmacokinetics

There is limited information regarding Calcium carbonate Pharmacokinetics in the drug label.

Nonclinical Toxicology

There is limited information regarding Calcium carbonate Nonclinical Toxicology in the drug label.

Clinical Studies

There is limited information regarding Calcium carbonate Clinical Studies in the drug label.

How Supplied

There is limited information regarding Calcium carbonate How Supplied in the drug label.

Storage

• Store at 20 - 25°C (68 - 77°F)

Images

Drug Images

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Package and Label Display Panel

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Patient Counseling Information

There is limited information regarding Calcium carbonate Patient Counseling Information in the drug label.

Precautions with Alcohol

Alcohol-Calcium carbonate interaction has not been established. Talk to your doctor about the effects of taking alcohol with this medication.

Brand Names

• REGULAR STRENGTH ANTACID CALCIUM SUPPLEMENT ®

Look-Alike Drug Names

There is limited information regarding Calcium carbonate Look-Alike Drug Names in the drug label.

Drug Shortage Status

Price

References

The contents of this FDA label are provided by the National Library of Medicine.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [3]

Overview

Calcium carbonate is a chemical compound, with the chemical formula CaCO₃. It is a common substance found as rock in all parts of the world, and is the main component of shells of marine organisms, snails, and eggshells. Calcium carbonate is the active ingredient in agricultural lime, and is usually the principal cause of hard water. It is commonly used medicinally as a calcium supplement or as an antacid.

Occurrence

Calcium carbonate is found naturally as the following minerals and rocks: Aragonite, Calcite, Vaterite or (μ-CaCO₃), Chalk, Limestone, Marble and Travertine

To test whether a mineral or rock contains calcium carbonate, strong acids, such as hydrochloric acid, can be added to it. If the sample does contain calcium carbonate, it will fizz and produce carbon dioxide and water. Weak acids such as acetic acid will react, albeit less vigorously. All of the rocks/minerals mentioned above will react with acid.

Chemical properties

See also: Carbonate

Calcium carbonate shares the typical properties of other carbonates. Notably:

1. it reacts with strong acids, releasing carbon dioxide:
   CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O

Calcium carbonate will react with water that is saturated with carbon dioxide to form the soluble calcium bicarbonate.

CaCO₃ + CO₂ + H₂O → Ca(HCO₃)₂

Preparation

The vast majority of calcium carbonate used in industry is extracted by mining or quarrying. Pure calcium carbonate (e.g. for food or pharmaceutical use), can be produced from a pure quarried source (usually marble).

Alternatively, calcium oxide is prepared by calcining crude calcium carbonate. Water is added to give calcium hydroxide, and carbon dioxide is passed through this solution to precipitate the desired calcium carbonate, referred to in the industry as precipitated calcium carbonate (PCC):

CaCO₃ → CaO + CO₂

CaO + H₂O → Ca(OH)₂

Ca(OH)₂ + CO₂ → CaCO₃ + H₂O

Uses

Health and dietary applications

Calcium carbonate is widely used medicinally as an inexpensive dietary calcium supplement or antacid. It may be used as a phosphate binder for the treatment of hyperphosphatemia (primarily in patients with chronic renal failure) when lanthanum carbonate is not prescribed. It is also used in the pharmaceutical industry as an inert filler for tablets and other pharmaceuticals.

As a food additive, it is used in some soy milk products as a source of dietary calcium; one study concludes that calcium carbonate is as bioavailable as ordinary cow's milk.

Solubility

With varying pH

We now consider the problem of the maximum solubility of calcium carbonate in normal atmospheric conditions (<math>\scriptstyle P_{\mathrm{CO}_2}</math> = 3.5 × 10⁻⁴ atm) when the pH of the solution is adjusted. This is for example the case in a swimming pool where the pH is maintained between 7 and 8 (by addition of NaHSO₄ to decrease the pH or of NaHCO₃ to increase it). From the above equations for the solubility product, the hydratation reaction and the two acid reactions, the following expression for the maximum [Ca²⁺] can be easily deduced:

<math>[\mathrm{Ca}^{2+}]_\mathrm{max} = \frac{K_\mathrm{sp}k_\mathrm{H}} {K_\mathrm{h}K_\mathrm{a1}K_\mathrm{a2}} \frac{[\mathrm{H}^+]^2}{P_{\mathrm{CO}_2}}</math>

showing a quadratic dependence in [H⁺]. The numerical application with the above values of the constants gives

Template:Chembox header width="170" align="center" |pH	7.0	7.2	7.4	7.6	7.8	8.0	8.2	8.27	8.4
Template:Chembox header width="170" align="center" |[Ca2+]max (10-4mol/L or °F)	1590	635	253	101	40.0	15.9	6.35	4.70	2.53
Template:Chembox header width="170" align="center"|[Ca2+]max (mg/L)	6390	2540	1010	403	160	63.9	25.4	18.9	10.1

Comments:

• decreasing the pH from 8 to 7 increases the maximum Ca²⁺ concentration by a factor 100
• note that the Ca²⁺ concentration of the previous table is recovered for pH = 8.27
• keeping the pH to 7.4 in a swimming pool (which gives optimum HClO/OCl⁻ ratio in the case of "chlorine" maintenance) results in a maximum Ca²⁺ concentration of 1010 mg/L. This means that successive cycles of water evaporation and partial renewing may result in a very hard water before CaCO₃ precipitates. Addition of a calcium sequestrant or complete renewing of the water will solve the problem.

Solubility in a strong or weak acid solution

Solutions of strong (HCl) or weak (acetic, phosphoric) acids are commercially available. They are commonly used to remove limescale deposits. The maximum amount of CaCO₃ that can be "dissolved" by one liter of an acid solution can be calculated using the above equilibrium equations.

• In the case of a strong monoacid with decreasing concentration [A] = [A⁻], we obtain (with CaCO₃ molar mass = 100 g):

width="160" Template:Chembox header |[A] (mol/L)	1	10−1	10−2	10−3	10−4	10−5	10−6	10−7	10−10
width="160" Template:Chembox header |Initial pH	0.00	1.00	2.00	3.00	4.00	5.00	6.00	6.79	7.00
width="160" Template:Chembox header |Final pH	6.75	7.25	7.75	8.14	8.25	8.26	8.26	8.26	8.27
width="160" Template:Chembox header |Dissolved CaCO3 (g per liter of acid)	50.0	5.00	0.514	0.0849	0.0504	0.0474	0.0471	0.0470	0.0470

where the initial state is the acid solution with no Ca²⁺ (not taking into account possible CO₂ dissolution) and the final state is the solution with saturated Ca²⁺. For strong acid concentrations, all species have a negligible concentration in the final state with respect to Ca²⁺ and A⁻ so that the neutrality equation reduces approximately to 2[Ca²⁺] = [A⁻] yielding <math>\scriptstyle[\mathrm{Ca}^{2+}] \simeq \frac{[\mathrm{A}^-]}{2}</math>. When the concentration decreases, [HCO₃⁻] becomes non negligible so that the preceding expression is no longer valid. For vanishing acid concentrations, we recover the final pH and the solubility of CaCO₃ in pure water.

• In the case of a weak monoacid (here we take acetic acid with pK_A = 4.76) with decreasing concentration [A] = [A⁻]+[AH], we obtain:

width="160" Template:Chembox header |[A] (mol/L)	1	10−1	10−2	10−3	10−4	10−5	10−6	10−7	10−10
width="160" Template:Chembox header |Initial pH	2.38	2.88	3.39	3.91	4.47	5.15	6.02	6.79	7.00
width="160" Template:Chembox header |Final pH	6.75	7.25	7.75	8.14	8.25	8.26	8.26	8.26	8.27
width="160" Template:Chembox header |Dissolved CaCO3 (g per liter of acid)	49.5	4.99	0.513	0.0848	0.0504	0.0474	0.0471	0.0470	0.0470

We see that for the same total acid concentration, the initial pH of the weak acid is less acid than the one of the strong acid; however, the maximum amount of CaCO₃ which can be dissolved is approximately the same. This is because in the final state, the pH is larger that the pK_A, so that the weak acid is almost completely dissociated, yielding in the end as many H⁺ ions as the strong acid to "dissolve" the calcium carbonate.

• The calculation in the case of phosphoric acid (which is the most widely used for domestic applications) is more complicated since the concentrations of the four dissociation states corresponding to this acid must be calculated together with [HCO₃⁻], [CO₃²⁻], [Ca²⁺], [H⁺] and [OH⁻]. The system may be reduced to a seventh degree equation for [H⁺] the numerical solution of which gives

width="160" Template:Chembox header |[A] (mol/L)	1	10−1	10−2	10−3	10−4	10−5	10−6	10−7	10−10
width="160" Template:Chembox header |Initial pH	1.08	1.62	2.25	3.05	4.01	5.00	5.97	6.74	7.00
width="160" Template:Chembox header |Final pH	6.71	7.17	7.63	8.06	8.24	8.26	8.26	8.26	8.27
width="160" Template:Chembox header |Dissolved CaCO3 (g per liter of acid)	62.0	7.39	0.874	0.123	0.0536	0.0477	0.0471	0.0471	0.0470

where [A] = [H₃PO₄] + [H₂PO₄⁻] + [HPO₄²⁻] + [PO₄³⁻]. We see that phosphoric acid is more efficient than a monoacid since at the final almost neutral pH, the second dissociated state concentration [HPO₄²⁻] is not negligible (see phosphoric acid ).

External links

• Template:PubChemLink
• ATC codes: A02AC01 (WHO) and A12AA04 (WHO)

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