|June 2003 · Vol. 15, No. 6
Judicious use of magnesium sulfate for eclampsia
The landmark Magpie study confirmed magnesium’s effectiveness in treating and preventing pregnancy-related seizures. Some Ob/Gyns fear side effects and toxicity, however. This practical guide tells how to assess risk and select the appropriate regimen.
Dr. Koos is professor and vice chair for academic affairs, and Dr. Purcell is chief resident, department of obstetrics and gynecology, David Geffen School of Medicine at University of California, Los Angeles.
Give magnesium sulfate at the time of diagnosis to all preeclamptic patients who are to be delivered.
Administration of magnesium sulfate for new-onset hypertension and preeclampsia remote from term is controversial.
Even with therapeutic serum concentrations of magnesium, convulsions are possible.
Magnesium sulfate should be administered for 24 hours after delivery or after the last postpartum seizure.
Safe administration requires vigilant monitoring of reflexes, respiratory status, and urine output.
Although magnesium sulfate has been used to treat eclampsia since the 1920s, the most compelling evidence of its effectiveness has come in the past year. Yet some Ob/Gyns hesitate to use this agent because of potential side effects and the risk of toxicity.
Last year’s headline-grabbing Magpie Trial1 confirmed a previous, smaller randomized study2 as well as a number of small controlled trials3 indicating that magnesium sulfate is better than placebo1,2 for seizure prophylaxis. Other large, randomized trials have demonstrated the drug’s superiority to nimodipine4 and phenytoin5 in preventing convulsions and to diazepam and phenytoin6 as therapy for eclampsia (TABLE 1).