Magnesium sulfate therapy in pregnancy to stop seizures has a therapeutic level in which range?

Magnesium sulfate therapy in pregnancy to stop seizures has a therapeutic level in which range?

• A. 2-4
• B. 3-5
• C. 4-7
• D. 8-10

Answer: (C)

The therapeutic range for magnesium sulfate used to prevent seizures in pregnancy is 4 to 7 mEq/L. This level provides enough CNS depression to avert seizures without tipping into toxicity. If the level is too low, seizures can still occur; if it becomes too high, toxicity emerges, beginning with loss of deep tendon reflexes and progressing to respiratory depression and possibly cardiac arrest. That’s why clinicians monitor reflexes, respiratory rate, and urine output, and keep calcium gluconate on hand as an antidote. Since magnesium is cleared by the kidneys, maintaining adequate urine output helps prevent accumulation.

The therapeutic range for magnesium sulfate used to prevent seizures in pregnancy is 4 to 7 mEq/L. This level provides enough CNS depression to avert seizures without tipping into toxicity. If the level is too low, seizures can still occur; if it becomes too high, toxicity emerges, beginning with loss of deep tendon reflexes and progressing to respiratory depression and possibly cardiac arrest. That’s why clinicians monitor reflexes, respiratory rate, and urine output, and keep calcium gluconate on hand as an antidote. Since magnesium is cleared by the kidneys, maintaining adequate urine output helps prevent accumulation.