Dosing & Uses
Dosage Forms & Strengths
injectable solution
- 40mg/mL
- 80mg/mL
- 50%
infusion solution
- 1g/100mL
- 2g/100mL
Hypomagnesemia
Mild: 1 g IM q6hr for 4 doses
Severe
- Asymptomatic: 4-8 g at ≤1 g/hr
- Symptomatic: 4-8 g at ≤4 g over 4-5 min
Toxemia of Pregnancy
Indicated to prevent seizures associated with pre-eclampsia, and for control of seizures with eclampsia
4-5 g (diluted in 250 mL NS/D5W) IV in combination with either (a) up to 10 g (20 mL of undiluted 50% solution) divided and administered IM into each buttock or (b) after initial IV dose, 1-2 g/hr IV; may administer q4hr as necessary
Torsades de Pointes
With pulse (ACLS): 1-2 g slow IV (diluted in 50-100 mL D5W) over 5-60 minutes, then 0.5-1 g/hr IV
Cardiac arrest (ACLS): 1-2 g slow IV (diluted in 10 mL D5W) over 5-20 minutes
Preterm Labor (Off-label)
Used as a tocolytic to stop preterm labor
Loading dose: 4-6 g IV over 20 minutes; maintenance: 2-4 g/hr IV for 12-24 hours as tolerated after contractions cease
Do not exceed 5-7 days of continuous treatment; longer treatment duration may lead to hypocalcemia in developing fetus resulting in neonates with skeletal abnormalities related to osteopenia
Dosing Modifications
Severe renal impairment: Do not exceed 20 g/48 hr
Dosage Forms & Strengths
injectable solution
- 40mg/mL
- 80mg/mL
- 50%
infusion solution
- 1g/100mL
- 2g/100mL
Acute Nephritis
100 mg/kg IM q4-6hr PRN or 20-40 mg/kg IM PRN
Severe: 100-200 mg/kg IV as 1-3% solution; administer total dose within 1 hr, one-half within first 15-20 minutes
Hypomagnesemia
IV/IM: 25-50 mg/kg q4-6hr for 3-4 doses PRN
PO: 100-200 mg/kg q6hr
Bronchospasm (Off-label)
25-50 mg/kg IV over 10-20 minutes
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (0)
Serious - Use Alternative (7)
- baloxavir marboxil
magnesium sulfate will decrease the level or effect of baloxavir marboxil by cation binding in GI tract. Avoid or Use Alternate Drug. Baloxavir may bind to polyvalent cations resulting in decreased absorption. Studies in monkeys showed concurrent use with calcium, aluminum, or iron caused significantly decreased plasma levels. Human studies not conducted.
- demeclocycline
magnesium sulfate decreases levels of demeclocycline by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug.
- doxycycline
magnesium sulfate decreases levels of doxycycline by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug.
- eltrombopag
magnesium sulfate decreases levels of eltrombopag by inhibition of GI absorption. Applies only to oral form of both agents. Contraindicated. Separate by at least 4 hours.
- minocycline
magnesium sulfate decreases levels of minocycline by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug.
- oxytetracycline
magnesium sulfate decreases levels of oxytetracycline by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug.
- tetracycline
magnesium sulfate decreases levels of tetracycline by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug.
Monitor Closely (21)
- atracurium
magnesium sulfate increases effects of atracurium by pharmacodynamic synergism. Use Caution/Monitor. Interaction occurs with parenteral magnesium.
- ciprofloxacin
magnesium sulfate decreases levels of ciprofloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Coadministration of ciprofloxacin with multivalent cation-containing products may reduce the bioavailability of ciprofloxacin by 90%. Administer ciprofloxacin at least 2 hours before or 6 hours after using these products. Use alternatives if available.
- cisatracurium
magnesium sulfate increases effects of cisatracurium by pharmacodynamic synergism. Use Caution/Monitor. Interaction occurs with parenteral magnesium.
- delafloxacin
magnesium sulfate will decrease the level or effect of delafloxacin by cation binding in GI tract. Modify Therapy/Monitor Closely. Oral delafloxacin form chelates with alkaline earth and transition metal cations. Administer oral delafloxacin at least 2 hr before or 6 hr after these agents.
- dichlorphenamide
dichlorphenamide and magnesium sulfate both decrease serum potassium. Use Caution/Monitor.
- fleroxacin
magnesium sulfate decreases levels of fleroxacin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.
- gemifloxacin
magnesium sulfate decreases levels of gemifloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.
- levofloxacin
magnesium sulfate decreases levels of levofloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.
- moxifloxacin
magnesium sulfate decreases levels of moxifloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.
- nifedipine
magnesium sulfate, nifedipine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Hypotension, neuromuscular blockade.
- ofloxacin
magnesium sulfate decreases levels of ofloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.
- onabotulinumtoxinA
magnesium sulfate increases effects of onabotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Interaction occurs with parenteral magnesium.
- pancuronium
magnesium sulfate increases effects of pancuronium by pharmacodynamic synergism. Use Caution/Monitor. Interaction occurs with parenteral magnesium.
- penicillamine
magnesium sulfate decreases levels of penicillamine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.
- rapacuronium
magnesium sulfate increases effects of rapacuronium by pharmacodynamic synergism. Use Caution/Monitor. Interaction occurs with parenteral magnesium.
- rilpivirine
magnesium sulfate decreases levels of rilpivirine by increasing gastric pH. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Coadministration of antacids with rilpivirine may cause significant decreases in rilpivirine plasma concentrations because of increased gastric pH. If antacids must be administered, they should given at least 2 hr before or at least 4 hr after rilpivirine.
- rimabotulinumtoxinB
magnesium sulfate, rimabotulinumtoxinB. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Anticholinergics may enhance botulinum toxin effects. Closely monitor for increased neuromuscular blockade.
- rocuronium
magnesium sulfate increases effects of rocuronium by pharmacodynamic synergism. Use Caution/Monitor. Interaction occurs with parenteral magnesium.
- sodium polystyrene sulfonate
sodium polystyrene sulfonate increases levels of magnesium sulfate by decreasing renal clearance. Use Caution/Monitor. Risk of seizure.
- succinylcholine
magnesium sulfate increases effects of succinylcholine by pharmacodynamic synergism. Use Caution/Monitor. Interaction occurs with parenteral magnesium.
- vecuronium
magnesium sulfate increases effects of vecuronium by pharmacodynamic synergism. Use Caution/Monitor. Interaction occurs with parenteral magnesium.
Minor (40)
- amikacin
amikacin decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- amiloride
amiloride increases levels of magnesium sulfate by decreasing renal clearance. Minor/Significance Unknown.
- amphotericin B deoxycholate
amphotericin B deoxycholate decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- bazedoxifene/conjugated estrogens
bazedoxifene/conjugated estrogens decreases levels of magnesium sulfate by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.
- bendroflumethiazide
bendroflumethiazide decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- bumetanide
bumetanide decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- calcitonin salmon
calcitonin salmon increases levels of magnesium sulfate by decreasing renal clearance. Minor/Significance Unknown.
- chlorothiazide
chlorothiazide decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- chlorthalidone
chlorthalidone decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- conjugated estrogens
conjugated estrogens decreases levels of magnesium sulfate by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.
- conjugated estrogens, vaginal
conjugated estrogens, vaginal decreases levels of magnesium sulfate by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.
- cyclopenthiazide
cyclopenthiazide decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- dextrose
dextrose decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- dextrose (Antidote)
dextrose (Antidote) decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- digoxin
digoxin decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- doxercalciferol
doxercalciferol increases levels of magnesium sulfate by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.
- drospirenone
drospirenone increases levels of magnesium sulfate by decreasing renal clearance. Minor/Significance Unknown.
- estradiol
estradiol decreases levels of magnesium sulfate by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.
- estrogens conjugated synthetic
estrogens conjugated synthetic decreases levels of magnesium sulfate by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.
- estrogens esterified
estrogens esterified decreases levels of magnesium sulfate by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.
- estropipate
estropipate decreases levels of magnesium sulfate by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.
- ethacrynic acid
ethacrynic acid decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- furosemide
furosemide decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- gentamicin
gentamicin decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- glucagon intranasal
glucagon intranasal increases levels of magnesium sulfate by decreasing renal clearance. Minor/Significance Unknown.
- hydrochlorothiazide
hydrochlorothiazide decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- ibandronate
magnesium sulfate decreases levels of ibandronate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.
- indapamide
indapamide decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- mannitol
mannitol decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- mestranol
mestranol decreases levels of magnesium sulfate by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.
- methyclothiazide
methyclothiazide decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- metolazone
metolazone decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- neomycin PO
neomycin PO decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- nitrofurantoin
magnesium sulfate decreases levels of nitrofurantoin by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.
- paromomycin
paromomycin decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- spironolactone
spironolactone increases levels of magnesium sulfate by decreasing renal clearance. Minor/Significance Unknown.
- streptomycin
streptomycin decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- tobramycin
tobramycin decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- torsemide
torsemide decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.
- triamterene
triamterene increases levels of magnesium sulfate by decreasing renal clearance. Minor/Significance Unknown.
Adverse Effects
Frequency Not Defined
Circulatory collapse
Respiratory paralysis
Hypothermia
Pulmonary edema
Depressed reflexes
Hypotension
Flushing
Drowsiness
Depressed cardiac function
Diaphoresis
Hypocalcemia
Hypophosphatemia
Hyperkalemia
Visual changes
Warnings
Contraindications
Hypersensitivity
Myocardial damage, diabetic coma, heart block
Hypermagnesemia
Hypercalcemia
Administration during 2 hours preceding delivery for mothers with toxemia of pregnancy
Cautions
Fetal skeletal demineralization, hypocalcemia, and hypermagnesemia abnormalities reported with continuous long-term use (ie, longer than 5-7 days) for off-label treatment of preterm labor in pregnant women; the effect on the developing fetus may result in neonates with skeletal abnormalities
In patients with renal impairment, ensure that renal excretory capacity is not exceeded
Use with caution in digitalized patients
Use with extreme caution in patients with myasthenia gravis or other neuromuscular disease
Hypomagnesemia is usually associated with hypokalemia (potassium levels must be normalized)
Monitor renal function, blood pressure, respiratory rate, and deep tendon reflex when magnesium sulfate is administered parenterally
Pregnancy & Lactation
Pregnancy category: D
Fetal skeletal demineralization, hypocalcemia, and hypermagnesemia reported with continuous long-term use (ie, longer than 5-7 days) for off-label treatment of preterm labor in pregnant women; the effect on the developing fetus may result in neonates with skeletal abnormalities
Continuous administration of magnesium sulfate injection to treat preterm labor is not approved and that the safety and efficacy of use for this indication are not established
Lactation: Safe
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Depresses CNS, blocks peripheral neuromuscular transmission, produces anticonvulsant effects; decreases amount of acetylcholine released at end-plate by motor nerve impulse
Slows rate of SA node impulse formation in myocardium and prolongs conduction time
Promotes movement of calcium, potassium, and sodium in and out of cells and stabilizes excitable membranes
Promotes osmotic retention of fluid in colon, causing distention and increased peristaltic activity, which subsequently results in bowel evacuation
Absorption
Onset (anticonvulsant): IV, immediate; IM, 1 hr
Duration (anticonvulsant): IV, 30 min; IM, 3-4 hr
Distribution
Protein bound: 30%
Extracellular distribution: 1-2%
Elimination
Excretion: Urine
Administration
IV Incompatibilities
Solution: IV fat emulsion 10%
Additive: Amphotericin B, cyclosporine, dobutamine, polymyxin B sulfate, procaine, sodium bicarbonate
Y-site: Alatrofloxacin, amiodarone (at 500 mg/mL MgSO4; may be compatible at 20 mg/mL), amphotericin B cholesteryl sulfate, cefepime, ciprofloxacin (?)
IV Preparation
Intermittent infusion: Dilute to 60 mg/mL
IV Administration
Infuse over 2-4 hr (hypomagnesemia) or as otherwise specified; rate not to exceed 125 mg/kg/hr
In severe cases, half of the dose may be infused over first 15-20 minutes
Rapid infusions (over 10-20 minutes) may be used for treatment of severe asthma or torsades de pointes ventricular tachycardia
Cautiously infuse diluted solution through patent IV line
IM Administration
Dilute to maximum concentration of 200 mg/mL before injection
Images
| BRAND | FORM. | UNIT PRICE | PILL IMAGE |
|---|---|---|---|
| magnesium sulfate injection - | 4 mEq/mL (50 %) vial |  | |
| magnesium sulfate injection - | 4 mEq/mL (50 %) vial |  | |
| magnesium sulfate injection - | 4 mEq/mL (50 %) vial |  | |
| magnesium sulfate injection - | 4 mEq/mL (50 %) vial |  | |
| magnesium sulfate injection - | 4 mEq/mL (50 %) vial |  | |
| magnesium sulfate injection - | 4 mEq/mL (50 %) vial |  | |
| magnesium sulfate injection - | 4 mEq/mL solution |  | |
| magnesium sulfate injection - | 4 mEq/mL (50 %) vial |  | |
| magnesium sulfate injection - | 4 mEq/mL (50 %) vial |  | |
| magnesium sulfate injection - | 4 mEq/mL (50 %) vial |  |
Copyright © 2010 First DataBank, Inc.
Patient Handout
magnesium sulfate injection
NO MONOGRAPH AVAILABLE AT THIS TIME
USES: Consult your pharmacist.
HOW TO USE: Consult your pharmacist.
SIDE EFFECTS: Consult your pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
PRECAUTIONS: Consult your pharmacist.
DRUG INTERACTIONS: Consult your pharmacist.Keep a list of all your medications with you, and share the list with your doctor and pharmacist.
OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.
NOTES: No monograph available at this time.
MISSED DOSE: Consult your pharmacist.
STORAGE: Consult your pharmacist.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.
Information last revised July 2016. Copyright(c) 2022 First Databank, Inc.
IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
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