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Magnesium Sulfate Dosage

Medically reviewed by Drugs.com. Last updated on Jun 12, 2024.

Applies to the following strengths: 50%; 10 mg/mL-D5%; 20 mg/mL-D5%; 40 mg/mL-D5%; 80 mg/mL-D5%; 125 mg/mL; 10 g/1000 mL; 40 mg/mL; 80 mg/mL; 100 mg/mL; 2 g/50 mL-sterile water; 4 g/50 mL-sterile water; 4 g/100 mL-sterile water; 20 g/500mL-sterile water; 40 g/1000 mL-sterile water; 1 g/50 mL-D5%; 2 g/50 mL-D5%; 6 g/50 mL-D5%; 4 g/100 mL-NaCl 0.9%; 1 g/50 mL-NaCl 0.9%; 1 g/100 mL-NaCl 0.9%; 2 g/50 mL-NaCl 0.9%; 6 g/50 mL-NaCl 0.9%; 3 g added to NaCl 0.9% 50 mL; 6 g added to NaCl 0.9% 100 mL; 2 g added to D5% 50 mL; 4 g added to D5% 100 mL; 50 g added to LR 500 mL; 20 g added to LR 500 mL; 10 g added to D5% 250 mL; 3 g added to D5% 100 mL; 40 mg/mL-LR; 80 mg/mL-LR; 120 mg/mL-D5%; 83 mg/mL-D5%; 83 mg/mL-LR; 1000 mg/ 50 mL-NaCl 0.9%; 2 g/100 mL-NaCl 0.9%; 2 g/100 mL-D5%; 6 g/100 mL-D5%

Usual Adult Dose for Hypomagnesemia

1 gram IM every 6 hours for 4 doses (mild hypomagnesemia) or as much as 250 mg/kg IM within a 4-hour period (severe hypomagnesemia)
OR
5 grams in 1 liter of appropriate diluent IV over 3 hours


Comments:

Usual Adult Dose for Atrial Tachycardia

3 to 4 grams (30 to 40 mL of a 10% solution) IV over 30 seconds

Comments:


Use: Paroxysmal atrial tachycardia

Usual Adult Dose for Pre-eclampsia/Eclampsia

Severe pre-eclampsia or eclampsia:
Initial dose: 4 to 5 grams IV in 250 mL of appropriate diluent, with simultaneous IM administration of up to 5 grams (10 mL undiluted solution) in EACH buttock; total dose: 10 to 14 grams


Maintenance dose: 4 to 5 grams IM into alternate buttocks every 4 hours as needed
OR
Maintenance dose: 1 to 2 grams/hour IV by constant infusion
Maximum dose: 30 to 40 grams/day

Comments:


Uses: Prevention and control of seizures in pre-eclampsia and eclampsia

Usual Adult Dose for Constipation

2 to 4 level teaspoons dissolved in 8 ounces water orally

Maximum dose: 2 doses per day

Uses: Cathartic or laxative

Usual Adult Dose for Barium Poisoning

1 to 2 grams IV


Use: To counteract the muscle-stimulating effects of barium poisoning

Usual Adult Dose for Seizures

1 gram intramuscularly or IV


Use: Seizures associated with epilepsy, glomerulonephritis, or hypothyroidism

Usual Adult Dose for Cerebral Edema

2.5 grams (25 mL of a 10% solution) IV


Use: Reduction of cerebral edema

Usual Pediatric Dose for Constipation

Epsom Salt:

12 years and older: 2 to 4 level teaspoons dissolved in 8 ounces water orally
6 to 11 years: 1 to 2 level teaspoons dissolved in 8 ounces of water orally
Under 6 years: Not recommended
Maximum dose: 2 doses per day

Comments:


Uses: Cathartic or laxative

Renal Dose Adjustments

Use with caution.


Prevention/Control of pre-eclamptic and eclamptic seizures:

Liver Dose Adjustments

No adjustment recommended.

Dialysis

Data not available

Other Comments

Administration advice:


IV compatibility:

Monitoring:

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.