Used in a number of situations in obstetrics:
prophylaxis in pre-eclampsia
treatment of eclamptic seizure
pre-term labour to promote fetal neuroprotection
Those women deemed at higher risk of eclamptic seizures will be loaded with 4g MgSO4 over 5-15mins, followed by 1g/hr for 24hrs.
In life-threatening situations where IV access is not possible, or is being attained, it can also be given IM mixed with 1ml 1% lignocaine.