Magnesium hydroxide

Identification

Summary

Magnesium hydroxide is an inorganic compound used as a laxative and antacid.

Brand Names

Almacone, Duo Fusion, Gelusil, Maalox Plus, Mi-acid, Mi-acid Double Strength, Mintox Plus, Mylanta, Mylanta Tonight, Pedia-lax Liquid, Pepcid Complete, Rolaids Advanced, Rolaids Reformulated Aug 2006, Rolaids Ultra Strength, Zegerid With Magnesium Hydroxide

Generic Name

Magnesium hydroxide

DrugBank Accession Number

DB09104

Background

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

Similar Structures

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.

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Associated Conditions

Associated Therapies

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.

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.

Drug	Interaction
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Abacavir	Abacavir may decrease the excretion rate of Magnesium hydroxide which could result in a higher serum level.
Aceclofenac	Aceclofenac may decrease the excretion rate of Magnesium hydroxide which could result in a higher serum level.
Acemetacin	Acemetacin may decrease the excretion rate of Magnesium hydroxide which could result in a higher serum level.
Acetaminophen	Magnesium hydroxide can cause a decrease in the absorption of Acetaminophen resulting in a reduced serum concentration and potentially a decrease in efficacy.
Acetazolamide	The risk or severity of adverse effects can be increased when Acetazolamide is combined with Magnesium hydroxide.
Acetophenazine	Magnesium hydroxide can cause a decrease in the absorption of Acetophenazine resulting in a reduced serum concentration and potentially a decrease in efficacy.
Aclidinium	The therapeutic efficacy of Magnesium hydroxide can be decreased when used in combination with Aclidinium.
Acrivastine	Magnesium hydroxide may decrease the excretion rate of Acrivastine which could result in a higher serum level.
Acyclovir	Acyclovir may decrease the excretion rate of Magnesium hydroxide which could result in a higher serum level.
Adefovir dipivoxil	Adefovir dipivoxil may decrease the excretion rate of Magnesium hydroxide which could result in a higher serum level.

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Food Interactions

No interactions found.

Products

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Active Moieties

Name	Kind	UNII	CAS	InChI Key
Magnesium cation	ionic	T6V3LHY838	22537-22-0	JLVVSXFLKOJNIY-UHFFFAOYSA-N
Magnesium	unknown	I38ZP9992A	7439-95-4	RSHAOIXHUHAZPM-UHFFFAOYSA-N
Hydroxide ion	ionic	9159UV381P	14280-30-9	XLYOFNOQVPJJNP-UHFFFAOYSA-M

Over the Counter Products

Name	Dosage	Strength	Route	Labeller	Marketing Start	Marketing End
Basic Care Milk Of Magnesia	Suspension	1200 mg/15mL	Oral	L. Perrigo Company	2018-09-28	Not applicable
Careone Milk Of Magnesia	Suspension	1200 mg/15mL	Oral	American Sales Company	2012-08-26	Not applicable
Careone Milk Of Magnesia	Suspension	1200 mg/15mL	Oral	American Sales Company	2012-07-27	2018-05-04
Careone Milk Of Magnesia	Suspension	1200 mg/15mL	Oral	American Sales Company	2012-08-05	Not applicable
CareOne Milk of Magnesia Cherry	Liquid	1200 mg/15mL	Oral	Retail Business Services, Llc.	2022-04-22	Not applicable
Careone Milk of magnesia Original Milk of Magnesia Original	Liquid	1200 mg/15mL	Oral	Retail Business Services, Llc.	2022-04-27	Not applicable
Childrens Oral Saline Laxative	Tablet, chewable	400 mg/1	Oral	Wal-Mart Stores,Inc.,	2020-03-10	Not applicable
CVS Health Childrens Saline Laxative	Tablet, chewable	400 mg/1	Oral	CVS Pharmacy,Inc.	2019-05-16	Not applicable
Dermagran II Ointment - 0.25%	Ointment	.25 %	Topical	Trans Canaderm Inc.	1996-01-01	1996-09-10
Dermagran II Ointment 0.25%	Ointment	.25 %	Topical	Canadian Medical Supply Inc.	1993-12-31	1996-09-09

Mixture Products

Name	Ingredients	Dosage	Route	Labeller	Marketing Start	Marketing End
ACED FULL SUSPENSION	Magnesium hydroxide (4 g) + Aluminum hydroxide (4 g) + Simethicone (400 mg)	Suspension	Oral	COASPHARMA S.A.S.	2018-06-12	Not applicable
Acid Controller Complete	Magnesium hydroxide (165 mg/1) + Calcium carbonate (800 mg/1) + Famotidine (10 mg/1)	Tablet, chewable	Oral	Shopko Stores Operating	2013-06-05	2016-11-16
Acid Controller Complete	Magnesium hydroxide (165 mg/1) + Calcium carbonate (800 mg/1) + Famotidine (10 mg/1)	Tablet, chewable	Oral	Safeway	2008-08-06	2017-01-19
Acid Controller Complete	Magnesium hydroxide (165 mg/1) + Calcium carbonate (800 mg/1) + Famotidine (10 mg/1)	Tablet, chewable	Oral	Shopko Stores Operating	2013-06-05	2017-01-15
Acid Controller Complete dual action	Magnesium hydroxide (165 mg/1) + Calcium carbonate (800 mg/1) + Famotidine (10 mg/1)	Tablet, chewable	Oral	Walgreen	2008-07-30	2017-07-25
Acid Controller Complete dual action	Magnesium hydroxide (165 mg/1) + Calcium carbonate (800 mg/1) + Famotidine (10 mg/1)	Tablet, chewable	Oral	Walgreen Company	2008-07-30	Not applicable
Acid Reducer Complete	Magnesium hydroxide (165 mg/1) + Calcium carbonate (800 mg/1) + Famotidine (10 mg/1)	Tablet, chewable	Oral	Shopko Stores Operating Co., LLC	2016-01-12	Not applicable
Acid Reducer Complete	Magnesium hydroxide (165 mg/1) + Calcium carbonate (800 mg/1) + Famotidine (10 mg/1)	Tablet, chewable	Oral	Rite Aid	2009-05-15	2017-09-08
Acid Reducer Complete	Magnesium hydroxide (165 mg/1) + Calcium carbonate (800 mg/1) + Famotidine (10 mg/1)	Tablet, chewable	Oral	Shopko Stores Operating Co., LLC	2016-01-06	Not applicable
Acid Reducer Complete	Magnesium hydroxide (165 mg/1) + Calcium carbonate (800 mg/1) + Famotidine (10 mg/1)	Tablet, chewable	Oral	Walgreen Company	2016-01-29	Not applicable

Unapproved/Other Products

Name	Ingredients	Dosage	Route	Labeller	Marketing Start	Marketing End	Region	Image
FIRST Mouthwash BLM	Magnesium 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)	Kit	Oral	CutisPharma, Inc.	2004-11-01	Not applicable
MAGNESIE CALCINEE LAFAR 100 G TOZ	Magnesium hydroxide (100 g)	Powder, for solution	Oral	LAFAR İLAÇ SAN. VE TİC. A.Ş.	2020-08-14	Not applicable

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

Drugs.com [Link]
Glow [Link]
Medicines [Link]
Drugs.com [Link]

External Links

KEGG Compound: C07876
PubChem Compound: 73981
PubChem Substance: 310265028
ChemSpider: 14107
RxNav: 6581
ChEBI: 6637
ChEMBL: CHEMBL1200718
Wikipedia: Magnesium_hydroxide

Clinical Trials

Clinical Trials

Phase	Status	Purpose	Conditions	Count
4	Completed	Treatment	Constipation	1
4	Completed	Treatment	Gastro-esophageal Reflux Disease (GERD)	1
4	Completed	Treatment	Soft Tissue Sarcoma (STS)	1
4	Unknown Status	Treatment	Esophageal Cancer / Malignant Neoplasm of Stomach	1
3	Completed	Supportive Care	Malignant Head and Neck Neoplasm / Mucositis / Radiation-Induced Disorder	1
3	Not Yet Recruiting	Prevention	Constipation, Opioid-Induced	1
3	Terminated	Treatment	Radiation-induced Oesophagitis	1
2	Completed	Not Available	Acid Reflux Disease / Gastro-esophageal Reflux Disease (GERD) / Heartburn / Regurgitation	1
2	Completed	Treatment	Heartburn	1
2, 3	Not Yet Recruiting	Prevention	Air Travel	1

Pharmacoeconomics

Manufacturers

Not Available

Packagers

Not Available

Dosage Forms

Form	Route	Strength
Suspension	Intra-articular; Oral
Tablet; tablet, chewable	Oral
Tablet	Oral	152 mg
Liquid	Oral
Tablet, chewable	Oral
Powder
Tablet	Oral	6 mg
Ointment	Topical	.25 %
Ointment	Topical	0.25 %
Tablet, chewable	Buccal	470 mg
Tablet, chewable	Oral	1200 mg/1
Solution	Oral
Kit	Oral
Suspension	Oral	8 g
Suspension	Oral	50 mg/ml
Gel	Oral
Tablet, chewable	Buccal
Gel	Buccal; Oral
Suspension	Oral	6 g
Suspension
Suspension	Oral
Suspension	Oral	26.98 g
Suspension	Oral	4 g
Powder, for suspension	Oral
Suspension	Oral	3.5 %
Tablet, chewable	Oral	200 MG
Tablet	Oral	200 mg
Liquid	Oral	1200 mg/15mL
Suspension	Oral	8.5 g
Powder	Oral
Powder	Oral	45 G/100g
Powder	Oral	45 %
Powder	Oral	900 MG
Powder, for suspension	Oral	45 %
Powder, for suspension	Oral	90 %
Tablet, chewable	Oral	825 MG
Tablet	Oral	385 mg
Powder, for solution	Oral
Powder, for suspension	Oral
Tablet	Oral
Liquid	Oral	400 mg/5mL
Emulsion	Oral
Suspension	Topical
Suspension	Oral
Concentrate	Oral	2400 mg/10mL
Liquid	Oral	400 mg / 5 g
Suspension	Oral	1200 mg/15mL
Suspension	Oral	2400 mg/30mL
Suspension	Oral	2400 mg/10mL
Suspension	Oral	400 mg/5mL
Suspension	Oral	80 mg/1mL
Suspension	Oral	7.75 %
Liquid	Oral	8 g / 100 mL
Tablet	Oral	385 mg / tab
Suspension	Oral	400 mg / 5 mL
Suspension	Oral	80 mg / mL
Suspension	Oral	440 mg / 5 mL
Tablet, coated	Oral
Suspension	Oral	400 mg/5ml
Tablet	Oral
Tablet, chewable	Oral	400 mg/1
Tablet, chewable	Buccal	1200 mg
Liquid	Oral	80 mg / mL
Tablet, chewable	Oral	311 mg/1
Liquid	Oral	2400 mg/15mL
Lozenge	Oral
Cream	Oral
Tablet	Oral	250 mg
Tablet, chewable	Oral
Tablet	Oral	325 mg
Tablet
Tablet	Oral	300 mg

Prices

Not Available

Patents

Patent Number	Pediatric Extension	Approved	Expires (estimated)
US6489346	No	2002-12-03	2016-07-16
US6699885	No	2004-03-02	2016-07-16
US6645988	No	2003-11-11	2016-07-16
US7399772	No	2008-07-15	2016-07-16
US6814978	Yes	2004-11-09	2022-02-26
US5989588	Yes	1999-11-23	2018-03-30

Properties

State

Solid

Experimental Properties

Not Available

Predicted Properties

Property	Value	Source
logP	-0.57	ChemAxon
pKa (Strongest Acidic)	3.09	ChemAxon
Physiological Charge	2	ChemAxon
Hydrogen Acceptor Count	0	ChemAxon
Hydrogen Donor Count	0	ChemAxon
Polar Surface Area	0 Å²	ChemAxon
Rotatable Bond Count	0	ChemAxon
Refractivity	0 m³·mol^-1	ChemAxon
Polarizability	1.78 Å³	ChemAxon
Number of Rings	0	ChemAxon
Bioavailability	1	ChemAxon
Rule of Five	Yes	ChemAxon
Ghose Filter	No	ChemAxon
Veber's Rule	Yes	ChemAxon
MDDR-like Rule	No	ChemAxon

Predicted ADMET Features

Not Available

Spectra

Mass Spec (NIST): Not Available
Spectra: Not Available

Drug created at September 16, 2015 22:26 / Updated at May 28, 2022 06:24

Magnesium hydroxide

Identification

Structure for Magnesium hydroxide (DB09104)

Pharmacology

Interactions

Products

Categories

Chemical Identifiers

References

Clinical Trials

Pharmacoeconomics

Properties

Spectra