This is a substudy of the multicenter safety and efficacy Evaluation of intravenous Cardene ( nicardipine ) and Labetalol Use in the Emergency department ( CLUE ) trial that randomized patients to Food and Drug Administration-recommended intravenous dosing of nicardipine or labetalol to reach a physician predefined systolic BP ( SBP ) and target range ( TR ) of 20 mm Hg within 30 minutes .