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magnesium hydroxide
generic
Adult Dosing .
Dosage forms: SUSP: 400 mg per 5 mL, 1200 mg per 5 mL
Special Note
- [strength clarification]
- Info: 400 mg Mg hydroxide = 166.7 mg (13.7 mEq) elemental Mg; doses expressed as Mg hydroxide salt
constipation
- [2400-4800 mg PO qd prn]
- Alt: 2400-4800 mg/day PO divided bid-qid prn
dyspepsia
- [400-1200 mg PO qid prn]
renal dosing
- [see below]
- renal impairment: not defined, caution advised; renal failure: avoid use
- HD/PD: not defined
hepatic dosing
- [not defined]
Peds Dosing .
- Dosage forms: SUSP: 400 mg per 5 mL, 1200 mg per 5 mL
Special Note
- [strength clarification]
- Info: 400 mg Mg hydroxide = 166.7 mg (13.7 mEq) elemental Mg; doses expressed as Mg hydroxide salt
constipation
- [6 mo-1 yo (off-label)]
- Dose: 40 mg/kg/dose PO qd prn; Alt: 40 mg/kg/day PO divided bid-qid prn
- [2-5 yo]
- Dose: 400-1200 mg PO qd prn; Alt: 400-1200 mg/day PO divided bid-qid prn
- [6-11 yo]
- Dose: 1200-2400 mg PO qd prn; Alt: 1200-2400 mg/day PO divided bid-qid prn
- [12 yo and older]
- Dose: 2400-4800 mg PO qd prn; Alt: 2400-4800 mg/day PO divided bid-qid prn
dyspepsia
- [6-11 yo]
- Dose: 200-400 mg PO qid prn
- [12 yo and older]
- Dose: 400-1200 mg PO qid prn
renal dosing
- [see below]
- renal impairment: not defined, caution advised; renal failure: avoid use
- HD/PD: not defined
hepatic dosing
- [not defined]
Contraindications / Cautions .
- hypersensitivity to drug or ingredient
- renal failure
- colostomy
- ileostomy
- caution: GI obstruction
- caution: GI bleeding
- caution: renal impairment
- caution: botulism
Drug Interactions .
Overview
magnesium hydroxide
magnesium salt (antacid)
- gastric pH modulator
- polyvalent cation
- urine alkalinizer
Avoid/Use Alternative
- baloxavir marboxil
- calcitriol
- dextroamphetamine
- doxercalciferol
- erlotinib
- infigratinib
- lisdexamfetamine
- mefenamic acid
- mesalamine
- methamphetamine
- methenamine
- methylphenidate
- mexiletine
- naproxen
- nirogacestat
- potassium acid phosphate
- potassium phosphate
- quinine
- raltegravir
- selpercatinib
- sodium acid phosphate
- sodium phosphate (supplement)
- sotorasib
- trientine
- ursodiol
Monitor/Modify Tx
- alendronate
- allopurinol
- atazanavir
- atorvastatin
- azithromycin
- belumosudil
- bictegravir
- bisacodyl
- bosutinib
- cabotegravir
- calcium acetate
- calcium carbonate
- calcium chloride
- calcium citrate
- calcium gluconate
- captopril
- cefaclor
- cefdinir
- cefpodoxime proxetil
- cefuroxime axetil
- chloroquine
- chlorpromazine
- ciprofloxacin
- cysteamine
- dasatinib
- deferiprone
- delafloxacin
- demeclocycline
- dicyclomine
- digoxin
- dolutegravir
- domperidone
- doxycycline
- eltrombopag
- elvitegravir
- ferrous gluconate
- ferrous sulfate
- fexofenadine
- fluphenazine
- fosinopril
- gabapentin
- gabapentin enacarbil
- gefitinib
- glipizide
- hyoscyamine
- ibandronate
- itraconazole
- ketoconazole
- ledipasvir
- levofloxacin
- levoketoconazole
- levothyroxine
- lithium
- methscopolamine
- minocycline
- moxifloxacin
- mycophenolate mofetil
- mycophenolic acid
- neratinib
- nilotinib
- octreotide
- ofloxacin
- omadacycline
- pazopanib
- penicillamine
- peppermint
- perphenazine
- pexidartinib
- phenytoin
- prochlorperazine
- promethazine
- rifampin
- rilpivirine
- riociguat
- risedronate
- rosuvastatin
- sarecycline
- sotalol
- sparsentan
- sulfasalazine
- tetracycline
- thioridazine
- thyroid
- tipranavir
- triazolam
- trifluoperazine
- velpatasvir
Caution Advised
- amantadine
- amphetamine
- aspirin
- butalbital
- capsicum
- ephedra
- ephedrine injection
- flecainide
- fosamprenavir
- lactulose
- magnesium salicylate
- methohexital
- pentobarbital
- phenobarbital
- primidone
- pseudoephedrine
- quinidine (antiarrhythmic)
- quinidine (CYP2D6 inhibitor)
- salsalate
- sodium polystyrene sulfonate
Adverse Reactions .
Serious Reactions
- hypermagnesemia
Common Reactions
- diarrhea
- abdominal pain
- dehydration
- nausea
- vomiting
Safety/Monitoring .
Monitoring Parameters
Cr at baseline; electrolytes if Mg >50 mEq/day and renal impairment
Pregnancy/Lactation .
Pregnancy
Clinical Summary
may use during pregnancy; risk of fetal harm not expected based on limited human data
Lactation
Clinical Summary
may use while breastfeeding; no known risk of infant harm based on limited human data; inadequate human data available to assess effects on milk production
Pharmacology .
Metabolism: none; CYP450: none; Info: 15-30% systemic absorption
Excretion: urine, feces; Half-life: unknown
Subclass: Antacids ; Constipation: Osmotic Laxatives
Mechanism of Action
neutralizes gastric acidity; causes water retention in stool, producing laxative effect
Formulary .
No Formulary Selected
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