From the Research
The recommended infusion rate for 1 gram of magnesium sulfate (MgSO4) is typically 1 gram over 1 hour when administered intravenously, as evidenced by a study comparing serum magnesium levels during infusion at 1 gram/hour versus 2 grams/hour 1.
Key Considerations
- For most clinical situations, diluting the medication in 50-100 mL of compatible IV fluid (such as normal saline or D5W) is appropriate.
- This rate helps minimize adverse effects like flushing, hypotension, and discomfort at the infusion site.
- For urgent situations such as severe hypomagnesemia with symptoms or eclampsia, faster rates may be used under close monitoring.
Monitoring and Safety
- During administration, patients should be monitored for signs of magnesium toxicity including respiratory depression, hyporeflexia, and hypotension, especially in those with renal impairment since the kidneys excrete magnesium 2.
- Serum magnesium levels should be checked periodically during treatment to ensure therapeutic levels are maintained without reaching toxic concentrations.
Clinical Evidence
- A randomized clinical trial compared serum magnesium levels during intravenous infusion of magnesium sulfate at 1 gram/hour versus 2 grams/hour as a maintenance dose to prevent eclampsia in pregnant and postpartum women with severe preeclampsia, finding that the 1 gram/hour dose was effective with fewer side effects 1.
- Other studies have also supported the use of magnesium sulfate in preventing eclamptic fits and its safety for both mother and fetus 3, 4.