Efficacy of magnesium sulphate and phenytoin in the management of eclampsia. Phenytoin versus magnesium sulfate in preeclampsia: a pilot study. Which anticonvulsant for women with eclampsia? Evidence from the Collaborative Eclampsia Trial. Phenytoin sodium and magnesium sulphate in the management of eclampsia. Randomised study assessing the effect of phenytoin and magnesium sulphate on maternal cerebral circulation in eclampsia using transcranial Doppler ultrasound.
Fifty pregnant women admitted with diagnosis of eclampsia were randomly allocated to magnesium sulphate (Group A) or phenytoin sodium (Group B) treatment group. Incidence of recurrence of seizures maternal as well as perinatal morbidity and mortality were compared in both the groups. Mean maternal age, parity and gestational age was similar in both the groups. Mean birth weight was significantly lower in Group B compared to Group A. Seizure frequency prior to hospitalization was 5.4 +/- 4.7 in Group A and 4.8-3.6 in Group B. Mean time interval between occurrence of first seizure and hospitalization was 9.6 +/- 3.5 hours in Group A and 11.8 +/- 9.3 hours in Group B, the difference was not statistically significant. Women treated with phenytoin had a higher incidence of recurrent seizures (10/25-40%) than those treated with magnesium sulphate (2/25-8%). Majority of the women treated with phenytoin (6/10-60%) had single convulsion after initiation of anticonvulsant therapy and 1 woman of each group had recurrent convulsions (75). There was no significant difference in perinatal outcome in both the groups. Maternal morbidity was comparable in both the groups and there was no maternal death in either of the groups. A randomized clinical trial was designed to determine whether there are clinically demonstrable advantages of phenytoin over magnesium sulfate in preeclamptic patients because of the latter drug's uterine relaxant properties. An intravenous infusion, immediately after randomization, of either phenytoin or magnesium sulfate, with subsequent measurement of serum concentrations and maintenance of therapeutic levels was given to 103 preeclamptic and two eclamptic women. Observed were the rate of cervical dilation during active labor and change in hematocrit between predelivery and 24-hour postdelivery values and the incidence of side effects ascertained by interview. Compared with those receiving magnesium sulfate, patients receiving phenytoin had more rapid cervical dilation (3.3 cm/hr versus 1.5 cm/hr, p = 0.016) and a smaller fall in hematocrit after delivery (-4.7% versus -7.6%, p = 0.034). A significantly lower incidence of hot flushes (15% versus 46%, p < 0.005) and a trend toward less dyspnea and weakness were reported by phenytoin-treated patients. Our phenytoin regimen produced acceptable serum phenytoin levels (10 to 25 micrograms/ml) in 96% of patients. Eclampsia, the occurrence of a seizure in association with pre-eclampsia, remains an important cause of maternal mortality. Although it is standard practice to use an anticonvulsant for management of eclampsia, the choice of agent is controversial and there has been little properly controlled evidence to support any of the options. 1687 women with eclampsia were recruited into an international multicentre randomised trial comparing standard anticonvulsant regimens. Primary measures of outcome were recurrence of convulsions and maternal death. Data are available for 1680 (99.6%) women: 453 allocated magnesium sulphate versus 452 allocated diazepam, and 388 allocated magnesium sulphate versus 387 allocated phenytoin. Most women (99%) received the anticonvulsant that they had been allocated. Women allocated magnesium sulphate had a 52% lower risk of recurrent convulsions (95% CI 64% to 37% reduction) than those allocated diazepam (60 [13.2%] vs 126 [27.9%]; ie, 14.7 [SD 2.6] fewer women with recurrent convulsions per 100 women; 2p < 0.00001). Maternal mortality was non-significantly lower among women allocated magnesium sulphate. There were no significant differences in other measures of serious maternal morbidity, or in perinatal morbidity or mortality. Women allocated magnesium sulphate had a 67% lower risk of recurrent convulsions (95% CI 79% to 47% reduction) than those allocated phenytoin (22 [5.7%] vs 66 [17.1%] ie, 11.4 [SD 2.2] fewer women with recurrent convulsions per 100 women; 2p < 0.00001). Maternal mortality was nonsignificantly lower among women allocated magnesium sulphate. Women allocated magnesium sulphate were also less likely to be ventilated, to develop pneumonia, and to be admitted to intensive care facilities than those allocated phenytoin. The babies of women who had been allocated magnesium sulphate before delivery were significantly less likely to be intubated at the place of delivery, and to be admitted to a special care nursery, than the babies of mothers who had been allocated phenytoin. There is now compelling evidence in favour of magnesium sulphate, rather than diazepam or phenytoin, for the treatment of eclampsia. Twenty-two patients with eclampsia were randomly allocated to receive either intravenous phenytoin sodium or intravenous magnesium sulphate. The groups were comparable. No side-effects occurred and therapeutic levels were obtained in both groups. While none of the 11 patients managed with magnesium sulphate had further convulsions, four of the 11 treated with phenytoin sodium did and were subsequently effectively treated with magnesium sulphate. These results suggest that phenytoin sodium is not as effective an anticonvulsant in eclampsia as is magnesium sulphate. To assess maternal middle cerebral artery flow velocity patterns as measured by transcranial Doppler ultrasound (TCD) in eclampsia and to investigate the effect of the anticonvulsants magnesium sulphate (MgSO4) and phenytoin on cerebral circulation.
                Prospective randomised study.
                High care obstetric unit, King Edward VIII Hospital, Durban, South Africa.
                Twenty-four eclamptic patients: 13 received MgSO4 and 11 phenytoin.
                Middle cerebral artery flow velocity waveforms were measured using 2 MHz pulsed Doppler ultrasound via the transtemporal approach in eclamptic patients, before and 15 minutes after the loading dose of anticonvulsant.
                Magnesium sulphate significantly reduced the pulsatility index (P = 0.002) and mean flow velocity (P = 0.02) in the middle cerebral artery, whereas phenytoin failed to produce any statistically significant effect. However, differences between groups were not statistically significant. Systolic and diastolic blood pressures were reduced in both the MgSO4 and phenytoin groups.
                These findings provide firm evidence that MgSO4 relieves cerebral vasospasm, compared with phenytoin, and may therefore be the better drug for the prevention of eclamptic convulsion.
Magnesium sulphate, rather than phenytoin, for women with eclampsia reduces the risk ratio of recurrence of seizures, probably reduces the risk of maternal death, and improves outcome for the baby. Magnesium sulphate is the drug of choice for women with eclampsia. The use of phenytoin should be abandoned.