Magnesium sulphate versus phenytoin in eclampsia - Maternal and foetal outcome - A comparative study

Recurrent Seizures in 2 Patients with Magnesium Sulfate-Treated Eclampsia at a Secondary Hospital

BACKGROUND Recurrent seizure in patients with magnesium sulfate-treated eclampsia is very rare and requires meticulous management due to poor prognosis. The development of eclamptic convulsions is considered a preventable obstetric situation. Magnesium sulfate has been the drug of choice in such cases. However, some cases are persistent and need more aggressive treatment. CASE REPORT First case: A 20-year-old, nulliparous woman was referred from a private midwifery practice with history of convulsion, 40 weeks of gestational age (GA), and in the active phase of labor. She had been treated with magnesium sulfate and nifedipine beforehand. Her fetus was tachycardic, so an emergency caesarean section was done and placental abruption was found. The day after the surgery, the patient had recurrent seizures despite receiving a maintenance dose of magnesium sulfate. The patient then received thiopental sodium and remained stable. Second case: A 19-year-old, nulliparous woman came to the hospital with 40 weeks of GA, prolonged premature rupture of the membrane (PROM), preeclampsia, and cephalopelvic disproportion (CPD). An emergency caesarean section was performed. Eighteen hours after surgery, the patient had convulsions despite receiving magnesium sulfate maintenance therapy. We repeated the loading dose of 2 g magnesium sulfate, but the seizures persisted. Hence, midazolam was given and the seizures remained controlled. Both babies were delivered without any significant complications. CONCLUSIONS We report 2 cases of GIP0-0 women with 40 weeks GA who had magnesium sulfate-resistant eclampsia and needed additional anticonvulsant drugs. These cases show the importance of comprehensive management and the need for alternative drugs in eclampsia.

Time and sex dependent effects of magnesium sulphate on post-asphyxial seizures in preterm fetal sheep

KEY POINTS

We evaluated the effect of magnesium sulphate (MgSO₄ ) on seizures induced by asphyxia in preterm fetal sheep. MgSO₄ did not prevent seizures, but significantly reduced the total duration, number of seizures, seizure amplitude and average seizure burden. Saline-asphyxia male fetuses had significantly more seizures than female fetuses, but male fetuses showed significantly greater reduction in seizures during MgSO₄ infusion than female fetuses. A circadian profile of seizure activity was observed in all fetuses, with peak seizures seen around 04.00-06.00 h on the first and second days after the end of asphyxia. This study is the first to demonstrate that MgSO₄ has utility as an anti-seizure agent after hypoxia-ischaemia. More information is needed about the mechanisms mediating the effect of MgSO₄ on seizures and sexual dimorphism, and the influence of circadian rhythms on seizure expression.

ABSTRACT

Seizures are common in newborns after asphyxia at birth and are often refractory to anti-seizure agents. Magnesium sulphate (MgSO₄ ) has anticonvulsant effects and is increasingly given to women in preterm labour for potential neuroprotection. There is limited information on its effects on perinatal seizures. We examined the hypothesis that MgSO₄ infusion would reduce fetal seizures after asphyxia in utero. Preterm fetal sheep at 0.7 gestation (104 days, term = 147 days) were given intravenous infusions of either saline (n = 14) or MgSO₄ (n = 12, 160 mg bolus + 48 mg h^-1 infusion over 48 h). Fetuses underwent umbilical cord occlusion (UCO) for 25 min, 24 h after the start of infusion. The start time for seizures did not differ between groups, but MgSO₄ significantly reduced the total number of seizures (P < 0.001), peak seizure amplitude (P < 0.05) and seizure burden (P < 0.005). Within the saline-asphyxia group, male fetuses had significantly more seizures than females (P < 0.05). Within the MgSO₄ -asphyxia group, although both sexes had fewer seizures than the saline-asphyxia group, the greatest effect of MgSO₄ was on male fetuses, with reduced numbers of seizures (P < 0.001) and seizure burden (P < 0.005). Only 1 out of 6 MgSO₄ males had seizures on the second day post-UCO compared to 5 out of 6 MgSO₄ female fetuses (P = 0.08). Finally, seizures showed a circadian profile with peak seizures between 04.00 and 06.00 h on the first and second day post-UCO. Collectively, these results suggest that MgSO₄ may have utility in treating perinatal seizures and has sexually dimorphic effects.

The comparison of anti-seizure and tocolytic effects of phenytoin and magnesium sulphate in the treatment of eclampsia and preeclampsia: A randomised clinical trial

Background: To date, magnesium sulphate (MgSO₄) is the treatment of choice for prevention of seizure in eclampsia and preeclampsia. However, there are some limitations in the administration of MgSO₄ due to its tocolytic effects. The aim of this study was to compare the anticonvulsant and tocolytic effects of MgSO₄ and another drug, phenytoin, in patients with eclampsia and preeclampsia. Methods: This clinical trial was conducted on pregnant women hospitalised with eclampsia or preeclampsia, during 2014-2016. The subjects were randomly assigned to two treatment groups using blocking method based on disease (eclampsia or mild and severe preeclampsia). One group received MgSO₄ (group M) and another group received phenytoin (group P) as treatment. Each group consisted of 110 and 65 women with mild and severe preeclampsia, respectively (subgroup A), and 25 women with eclampsia (subgroup B). Duration of labor, the number of cesarean sections, convulsions and Apgar scores of infants were compared between the two groups and were considered as treatment outcomes. Results: Convulsion rate was significantly lower with MgSO₄ than phenytoin (P = 0.001). No seizure occurred in patients with mild preeclampsia in group P. Duration of stage one of labor (P < 0.001) and the number of cesarean sections (P = 0.040) were significantly higher in group M. However, one-minute Apgar scores for newborns were higher in women treated with MgSO₄ compared to that of phenytoin (P = 0.001). Five-minute Apgar was not significantly different. Conclusion: Although MgSO₄ is more effective than phenytoin for prevention of convulsion in eclampsia and severe preeclampsia, phenytoin may be considered for treatment of special conditions such as mild preeclampsia. Due to the tocolytic effects of MgSO₄ on increasing the duration of labor, the increased risk of cesarean section and the potential for toxicity, physicians should critically consider the best drug according to the condition of the patient.