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
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).
- Small Molecule
- Approved, Investigational
- Average: 58.32
- Chemical Formula
- Hidroxido de magnesio
- Magnesii hydroxidum
- Magnesio hidróxido
- Magnesium dihydroxide
- Magnesium hydroxide
- Milk of magnesia
- External IDs
- INS NO.528
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.Reduce drug development failure ratesBuild, train, & validate machine-learning modelswith evidence-based and structured datasets.Build, train, & validate predictive machine-learning models with structured datasets.
- Associated Conditions
- Associated Therapies
- Contraindications & Blackbox Warnings
- Avoid life-threatening adverse drug eventsImprove clinical decision support with information on contraindications & blackbox warnings, population restrictions, harmful risks, & more.Avoid life-threatening adverse drug events & improve clinical decision support.
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.
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.
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.
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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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.
- Not Available
- Pharmacogenomic Effects/ADRs
- Not Available
- 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 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.Identify potential medication risksEasily compare up to 40 drugs with our drug interaction checker.Get severity rating, description, and management advice.Learn more
- Food Interactions
- No interactions found.
- Drug product information from 10+ global regionsOur datasets provide approved product information including:dosage, form, labeller, route of administration, and marketing period.Access drug product information from over 10 global regions.
- 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 Region Image 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 2012-08-05 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 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 Region Image 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 Bem Bio Antiperspirant floral Magnesium hydroxide (10 g/100g) + Magnesium carbonate basic (10 g/100g) Aerosol, spray Topical Aeroflex Industria de Aerosol Ltda 2022-06-15 Not applicable Bem Bio Antiperspirant forest trails Magnesium hydroxide (10 g/100g) + Magnesium carbonate basic (10 g/100g) Aerosol, spray Topical Aeroflex Industria de Aerosol Ltda 2022-06-15 Not applicable Bem Bio Antiperspirant original Magnesium hydroxide (10 g/100g) + Magnesium carbonate basic (10 g/100g) Aerosol, spray Topical Aeroflex Industria de Aerosol Ltda 2022-06-15 Not applicable Bem Bio Antiperspirant sea breeze Magnesium hydroxide (10 g/100g) + Magnesium carbonate basic (10 g/100g) Aerosol, spray Topical Aeroflex Industria de Aerosol Ltda 2022-06-15 Not applicable Bem Bio Antiperspirant unscented Magnesium hydroxide (10 g/100g) + Magnesium carbonate basic (10 g/100g) Aerosol, spray Topical Aeroflex Industria de Aerosol Ltda 2022-06-15 Not applicable 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
- ATC Codes
- G04BX01 — Magnesium hydroxide
- G04BX — Other urologicals
- G04B — UROLOGICALS
- G04 — UROLOGICALS
- G — GENITO URINARY SYSTEM AND SEX HORMONES
- Drug Categories
- Agents that produce neuromuscular block (indirect)
- Alimentary Tract and Metabolism
- Aluminum and magnesium containing antacids
- Antacids and Adsorbents
- Basic Ointments and Protectants
- Drugs for Acid Related Disorders
- Drugs that are Mainly Renally Excreted
- Emollients Demulcents and Protectants
- Gastric Acid Lowering Agents
- Gastrointestinal Agents
- Genito Urinary System and Sex Hormones
- Laxatives, magnesium containing
- Magnesium Compounds
- Magnesium Salts
- Metal cations
- Metal divalent cations
- Osmotic Laxatives
- Chemical TaxonomyProvided by Classyfire
- 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.
- Inorganic compounds
- Super Class
- Mixed metal/non-metal compounds
- 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
- Alkaline earth metal hydroxide / Inorganic hydride / Inorganic oxide / Inorganic salt
- Molecular Framework
- Not Available
- External Descriptors
- magnesium hydroxide (CHEBI:6637)
- Affected organisms
- Humans and other mammals
- CAS number
- InChI Key
- IUPAC Name
- magnesium(2+) dihydroxide
- General References
- 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 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 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
- Not Available
- Not Available
- Dosage Forms
Form Route Strength Suspension Intra-articular; Oral Tablet; tablet, chewable Oral Tablet Oral 152 mg Liquid Oral Tablet, chewable Oral Tablet Oral 200 mg Aerosol, spray Topical Powder Tablet Oral 6 mg Ointment Topical .25 % Ointment Topical 0.25 % Tablet, chewable Buccal 470 mg Tablet, chewable Oral 600 mg/1 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 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
- Not Available
Patent Number Pediatric Extension Approved Expires (estimated) Region 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
- 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
- Mass Spec (NIST)
- Not Available
- Not Available
Drug created at September 16, 2015 22:26 / Updated at December 10, 2022 03:33