<qa>  What is the intent to treat?Patients who experience a seizure prior to receiving their study drug, but after being randomized to the study, will be removed from active participation in the study and treated according to routine practice in that institution. Those patients randomized to labetalol and who have a seizure on the drug will be started on magnesium sulfate per institutional protocol. Patients on the magnesium sulfate arm of the study who convulse will be continued on magnesium sulfate per institutional protocol. Since all of the above mentioned patients will have been randomized they will be included in the intent to treat analysis. Outcome data will be obtained on all randomized patients, regardless of whether they receive study drug or have to stop study drug. 