Magnesium hydroxide

Identification

Name
Magnesium hydroxide
Accession Number
DB09104
Description

Magnesium hydroxide is an inorganic compound. It is naturally found as the mineral brucite. Magnesium hydroxide can be used as an antacid or a laxative in either an oral liquid suspension or chewable tablet form. Additionally, magnesium hydroxide has smoke suppressing and flame retardant properties and is thus used commercially as a fire retardant. It can also be used topically as a deodorant or for the relief of canker sores (aphthous ulcers).

Type
Small Molecule
Groups
Approved, Investigational
Structure
Thumb
Weight
Average: 58.32
Monoisotopic: 57.990521206
Chemical Formula
H2MgO2
Synonyms
  • Hidroxido de magnesio
  • Magnesii hydroxidum
  • Magnesio hidróxido
  • Magnesium dihydroxide
  • Magnesium hydroxide
  • Milk of magnesia
External IDs
  • E-528
  • INS NO.528
  • INS-528

Pharmacology

Indication

Magnesium hydroxide can be used as an antacid or a laxative depending on the administered dose.

As an antacid, it is used for the temporary relief of heartburn, upset stomach, sour stomach or acid indigestion.

As a laxative, it is used for the relief of occasional constipation by promoting bowel movements for 30 minutes and up to 6 hours.

Associated Conditions
Contraindications & Blackbox Warnings
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Pharmacodynamics

As an antacid, magnesium hydroxide suspension neutralizes gastric acid by reacting with hydrochloric acid in the stomach to form magnesium chloride and water. It is practically insoluble in water and does not have any effect until it reacts with the hydrochloric acid in the stomach. There, it decreases the direct acid irritant effect and increases the pH in the stomach leading to inactivation of pepsin. Magnesium hydroxide enhances the integrity of the mucosal barrier of the stomach as well as improving the tone of both the gastric and esophageal sphincters.

As a laxative, the magnesium hydroxide works by increasing the osmotic effect in the intestinal tract and drawing water in. This creates distension of the colon which results in an increase in peristaltic movement and bowel evacuation.

Mechanism of action

The suspension of magnesium hydroxide is ingested and enters the stomach. According to the amount ingested, the magnesium hydroxide will either act as an antacid or a laxative.

Through the ingestion of 0.5-1.5 grams (in adults) the magnesium hydroxide will act by simple acid neutralization in the stomach. The hydroxide ions from the magnesium hydroxide suspension will combine with the acidic H+ ions of the hydrochloric acid made by the stomachs parietal cells. This neutralization reaction will result in the formation of magnesium chloride and water.

Through the ingestion of 2-5 grams (in adults) the magnesium hydroxide acts as a laxative in the colon. The majority of the suspension is not absorbed in the intestinal tract and will create an osmotic effect to draw water into the gut from surrounding tissues. With this increase of water in the intestines, the feces will soften and the intraluminal volume of the feces will increase. These effects still stimulate intestinal motility and induce the urge to defecate. Magnesium hydroxide will also release cholecystokinin (CKK) in the intestines which will accumulate water and electrolytes in the lumen and furthermore increase intestinal motility.

Absorption

About 15%-50% of magnesium hydroxide is absorbed very slowly through the small intestine.

Volume of distribution

The peak action and distribution of magnesium hydroxide are variable.

Protein binding

Magnesium hydroxide does not have any protein binding properties.

Metabolism

Unless a patient is deficient in magnesium, very little is absorbed by the intestine. Overall, about 15%-50% of the magnesium hydroxide suspension is absorbed systemically. However, it does not undergo any metabolism as it is rapidly excreted in the urine.

Route of elimination

After oral administration, up to 50% of the magnesium hydroxide suspension may be absorbed as magnesium ions through the small intestines and then rapidly excreted in the urine through the kidneys. The unabsorbed drug is mainly excreted in the feces and saliva.

Half-life

N/A

Clearance

Magnesium hydroxide is mainly excreted in the urine by the kidneys. Since the kidneys play a major role in its clearance, individuals with renal failure are at risk of hypermagnesemia with long term consumption as the appropriate amounts of magnesium may not be excreted.

Adverse Effects
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Toxicity

LD50=8500 mg/kg (rat, oral)

Common side effects include drowsiness or flushing (warmth, redness or tingly feeling).

Daily use of magnesium hydroxide can result in fluid and electrolyte disturbances.

Excessive use of the laxative effects of magnesium hydroxide may result in abdominal cramping, nausea and/or diarrhea.

In overdose, symptoms of gastrointestinal irritation and/or watery diarrhea may occur.

Magnesium hydroxide poisoning can result in hypermagnesemia which includes symptoms of: nausea, vomiting, flushing, thirst, hypotension, drowsiness, confusion, loss of tendon reflexes, muscle weakness, respiratory depression, cardiac arrhythmias, coma and cardiac arrest.

Not to be used in individuals with any form of kidney disease or renal failure, a magnesium restricted diet or with any sudden changes in bowel movement lasting over two weeks. Also not to be used in those individuals with abdominal pain, nausea, vomiting, symptoms of appendicitis or myocardial damage, heart block, fecal impaction, rectal fissures, intestinal obstruction or perforation or renal disease. Not to be used in women who are about to deliver as magnesium crosses the placenta and is excreted in small amounts in breast milk.

Using magnesium hydroxide with aluminum hydroxide can decrease the absorption rate of these drugs.

Magnesium hydroxide can react with digoxin, dicoumerol and cimetidine.

Use of ibuprofen with magnesium hydroxide can increase the absorption of the ibuprofen.

Use of magnesium hydroxide with penicallamine, bisphosphates, ketoconazole, quinolones or tetracycline can decrease the absorption of these drugs.

Enteric-coated tablets can be prematurely released when taken with magnesium hydroxide.

It is important to routinely monitor levels of serum magnesium and potassium in patients using magnesium hydroxide. Serum magnesium levels are necessary to determine how much magnesium is being absorbed and how much is being excreted by the kidneys. Excessive diarrhea can occur from use of magnesium hydroxide and thus it is important to also monitor serum potassium levels to ensure hypokalemia does not occur.

Affected organisms
  • Humans and other mammals
Pathways
Not Available
Pharmacogenomic Effects/ADRs
Not Available

Interactions

Drug Interactions
This information should not be interpreted without the help of a healthcare provider. If you believe you are experiencing an interaction, contact a healthcare provider immediately. The absence of an interaction does not necessarily mean no interactions exist.
DrugInteraction
AbacavirAbacavir may decrease the excretion rate of Magnesium hydroxide which could result in a higher serum level.
AcarboseAcarbose may decrease the excretion rate of Magnesium hydroxide which could result in a higher serum level.
AceclofenacAceclofenac may decrease the excretion rate of Magnesium hydroxide which could result in a higher serum level.
AcemetacinAcemetacin may decrease the excretion rate of Magnesium hydroxide which could result in a higher serum level.
AcetaminophenMagnesium hydroxide can cause a decrease in the absorption of Acetaminophen resulting in a reduced serum concentration and potentially a decrease in efficacy.
AcetazolamideThe risk or severity of adverse effects can be increased when Acetazolamide is combined with Magnesium hydroxide.
AcetophenazineMagnesium hydroxide can cause a decrease in the absorption of Acetophenazine resulting in a reduced serum concentration and potentially a decrease in efficacy.
AclidiniumAclidinium may decrease the excretion rate of Magnesium hydroxide which could result in a higher serum level.
AcrivastineMagnesium hydroxide may decrease the excretion rate of Acrivastine which could result in a higher serum level.
AcyclovirAcyclovir may decrease the excretion rate of Magnesium hydroxide which could result in a higher serum level.
Additional Data Available
  • Extended Description
    Extended Description

    Extended description of the mechanism of action and particular properties of each drug interaction.

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  • Severity
    Severity

    A severity rating for each drug interaction, from minor to major.

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  • Evidence Level
    Evidence Level

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  • Action
    Action

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Food Interactions
No interactions found.

Products

Active Moieties
NameKindUNIICASInChI Key
Magnesium cationionicT6V3LHY83822537-22-0JLVVSXFLKOJNIY-UHFFFAOYSA-N
MagnesiumunknownI38ZP9992A7439-95-4RSHAOIXHUHAZPM-UHFFFAOYSA-N
Hydroxide ionionic9159UV381P14280-30-9XLYOFNOQVPJJNP-UHFFFAOYSA-M
Over the Counter Products
NameDosageStrengthRouteLabellerMarketing StartMarketing EndRegionImage
Basic Care Milk Of MagnesiaSuspension1200 mg/15mLOralL. Perrigo Company2018-09-28Not applicableUS flag
Careone Milk Of MagnesiaSuspension1200 mg/15mLOralAmerican Sales Company2012-08-05Not applicableUS flag
Careone Milk Of MagnesiaSuspension1200 mg/15mLOralAmerican Sales Company2012-08-26Not applicableUS flag
Careone Milk Of MagnesiaSuspension1200 mg/15mLOralAmerican Sales Company2012-07-272018-05-04US flag
Childrens Oral Saline LaxativeTablet, chewable400 mg/1OralWal-Mart Stores,Inc.,2020-03-10Not applicableUS flag
CVS Health Childrens Saline LaxativeTablet, chewable400 mg/1OralCVS Pharmacy,Inc.2019-05-16Not applicableUS flag
Dermagran II Ointment - 0.25%OintmentTopicalTrans Canaderm Inc.1996-01-011996-09-10Canada flag
Dermagran II Ointment 0.25%OintmentTopicalCanadian Medical Supply Inc.1993-12-311996-09-09Canada flag
Dermagran II Ointment-ont Top 0.25%OintmentTopicalCanderm G.P.1998-05-072008-08-06Canada flag
Dg Health Milk Of MagnesiaSuspension1200 mg/15mLOralDolgencorp2014-05-07Not applicableUS flag
Additional Data Available
  • Application Number
    Application Number

    A unique ID assigned by the FDA when a product is submitted for approval by the labeller.

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  • Product Code
    Product Code

    A governmentally-recognized ID which uniquely identifies the product within its regulatory market.

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Mixture Products
NameIngredientsDosageRouteLabellerMarketing StartMarketing EndRegionImage
Acid Controller CompleteMagnesium hydroxide (165 mg/1) + Calcium carbonate (800 mg/1) + Famotidine (10 mg/1)Tablet, chewableOralShopko Stores Operating2013-06-052017-01-15US flag
Acid Controller CompleteMagnesium hydroxide (165 mg/1) + Calcium carbonate (800 mg/1) + Famotidine (10 mg/1)Tablet, chewableOralShopko Stores Operating2013-06-052016-11-16US flag
Acid Controller CompleteMagnesium hydroxide (165 mg/1) + Calcium carbonate (800 mg/1) + Famotidine (10 mg/1)Tablet, chewableOralSafeway2008-08-062017-01-19US flag
Acid Controller Complete dual actionMagnesium hydroxide (165 mg/1) + Calcium carbonate (800 mg/1) + Famotidine (10 mg/1)Tablet, chewableOralWalgreen2008-07-302017-07-25US flag
Acid Controller Complete dual actionMagnesium hydroxide (165 mg/1) + Calcium carbonate (800 mg/1) + Famotidine (10 mg/1)Tablet, chewableOralWalgreen Company2008-07-30Not applicableUS flag
Acid Reducer CompleteMagnesium hydroxide (165 mg/1) + Calcium carbonate (800 mg/1) + Famotidine (10 mg/1)Tablet, chewableOralShopko Stores Operating Co., LLC2016-01-06Not applicableUS flag
Acid Reducer CompleteMagnesium hydroxide (165 mg/1) + Calcium carbonate (800 mg/1) + Famotidine (10 mg/1)Tablet, chewableOralRite Aid2009-05-152017-09-08US flag
Acid Reducer CompleteMagnesium hydroxide (165 mg/1) + Calcium carbonate (800 mg/1) + Famotidine (10 mg/1)Tablet, chewableOralWalgreen Company2016-01-29Not applicableUS flag
Acid Reducer CompleteMagnesium hydroxide (165 mg/1) + Calcium carbonate (800 mg/1) + Famotidine (10 mg/1)Tablet, chewableOralWalgreen Company2016-01-29Not applicableUS flag
Acid Reducer CompleteMagnesium hydroxide (165 mg/1) + Calcium carbonate (800 mg/1) + Famotidine (10 mg/1)Tablet, chewableOralShopko Stores Operating Co., LLC2016-01-12Not applicableUS flag
Unapproved/Other Products
NameIngredientsDosageRouteLabellerMarketing StartMarketing EndRegionImage
FIRST Mouthwash BLMMagnesium hydroxide (3.15 g/236mL) + Aluminum hydroxide (3.15 g/236mL) + Dimethicone 410 (0.315 g/236mL) + Diphenhydramine hydrochloride (.2 g/.2g) + Lidocaine hydrochloride (1.6 g/1.6g)KitOralCutisPharma, Inc.2004-11-01Not applicableUS flag

Categories

ATC Codes
G04BX01 — Magnesium hydroxideA02AA04 — Magnesium hydroxide
Drug Categories
Chemical TaxonomyProvided by Classyfire
Description
This compound belongs to the class of inorganic compounds known as alkaline earth metal hydroxides. These are inorganic compounds in which the largest oxoanion is hydroxide, and in which the heaviest atom not in an oxoanion is an alkaline earth metal.
Kingdom
Inorganic compounds
Super Class
Mixed metal/non-metal compounds
Class
Alkaline earth metal oxoanionic compounds
Sub Class
Alkaline earth metal hydroxides
Direct Parent
Alkaline earth metal hydroxides
Alternative Parents
Inorganic salts / Inorganic oxides / Inorganic hydrides
Substituents
Alkaline earth metal hydroxide / Inorganic hydride / Inorganic oxide / Inorganic salt
Molecular Framework
Not Available
External Descriptors
magnesium hydroxide (CHEBI:6637)

Chemical Identifiers

UNII
NBZ3QY004S
CAS number
1309-42-8
InChI Key
VTHJTEIRLNZDEV-UHFFFAOYSA-L
InChI
InChI=1S/Mg.2H2O/h;2*1H2/q+2;;/p-2
IUPAC Name
magnesium(2+) dihydroxide
SMILES
[OH-].[OH-].[Mg++]

References

General References
  1. Drugs.com [Link]
  2. Glow [Link]
  3. Medicines [Link]
  4. Drugs.com [Link]
KEGG Compound
C07876
PubChem Compound
73981
PubChem Substance
310265028
ChemSpider
14107
RxNav
6581
ChEBI
6637
ChEMBL
CHEMBL1200718
Wikipedia
Magnesium_hydroxide
AHFS Codes
  • 56:04.00 — Antacids and Adsorbents
  • 84:24.12 — Basic Ointments and Protectants
  • 56:12.00 — Cathartics and Laxatives
  • 84:24.00 — Emollients Demulcents and Protectants

Clinical Trials

Clinical Trials
PhaseStatusPurposeConditionsCount
4CompletedTreatmentConstipation1
4CompletedTreatmentGastro-esophageal Reflux Disease (GERD)1
3Active Not RecruitingSupportive CareMalignant Head and Neck Neoplasm / Mucositis / Radiation-Induced Disorder1
3TerminatedTreatmentRadiation-induced Oesophagitis1
2CompletedNot AvailableAcid Reflux Disease / Gastro-esophageal Reflux Disease (GERD) / Heartburn / Regurgitation1
2CompletedTreatmentHeartburn1
1Active Not RecruitingTreatmentHealthy Volunteers / Novel Coronavirus Infectious Disease (COVID-19)1
1CompletedBasic ScienceHealthy Volunteers2
1CompletedOtherHealthy Volunteers1
1CompletedTreatmentHeartburn1

Pharmacoeconomics

Manufacturers
Not Available
Packagers
Not Available
Dosage Forms
FormRouteStrength
Tablet, chewableOral10 mg
Suspension200 ml
LiquidOral
SuspensionOral0.4 g
OintmentTopical
SuspensionOral32.501 g
Tablet, chewableBuccal470 mg
Tablet, chewableOral1200 mg/1
SolutionOral
KitOral
SuspensionOral4 g
SuspensionOral4000 mg
GelOral
SuspensionOral8.5 g
SuspensionOral
Powder5 gr
LiquidOral1200 mg/15mL
Powder45 %
Powder900 MG
Powder, for suspensionOral45 %
Powder, for suspensionOral90 %
Tablet825 MG
Suspension400 mg
Powder, for solutionOral100 g
Powder100 g
Powder, for suspension400 mg
LiquidOral400 mg/5mL
EmulsionOral
SuspensionOral
ConcentrateOral2400 mg/10mL
LiquidOral400 mg
SuspensionOral1200 mg/15mL
SuspensionOral2400 mg/30mL
SuspensionOral2400 mg/10mL
SuspensionOral400 mg/5mL
SuspensionOral80 mg/1mL
TabletOral
Tablet, coatedOral
SuspensionOral8 g
TabletOral
Tablet, chewableOral400 mg/1
SuspensionOral0.6 g
LiquidOral
Tablet, chewableOral311 mg/1
LiquidOral2400 mg/15mL
LozengeOral
Suspension83.35 mg
CreamOral
Tablet, chewableOral
Prices
Not Available
Patents
Patent NumberPediatric ExtensionApprovedExpires (estimated)Region
US6489346No2002-12-032016-07-16US flag
US6699885No2004-03-022016-07-16US flag
US6645988No2003-11-112016-07-16US flag
US7399772No2008-07-152016-07-16US flag
US6814978Yes2004-11-092022-02-26US flag
US5989588Yes1999-11-232018-03-30US flag
Additional Data Available
  • Filed On
    Filed On

    The date on which a patent was filed with the relevant government.

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Properties

State
Solid
Experimental Properties
Not Available
Predicted Properties
PropertyValueSource
logP-0.57ChemAxon
pKa (Strongest Acidic)3.09ChemAxon
Physiological Charge2ChemAxon
Hydrogen Acceptor Count0ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area0 Å2ChemAxon
Rotatable Bond Count0ChemAxon
Refractivity0 m3·mol-1ChemAxon
Polarizability1.78 Å3ChemAxon
Number of Rings0ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterNoChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleNoChemAxon
Predicted ADMET Features
Not Available

Spectra

Mass Spec (NIST)
Not Available
Spectra
Not Available

Drug created on September 16, 2015 16:26 / Updated on September 27, 2020 08:17

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