 If the desired BP lowering effect is not attained with study drug within 1 hour or not maintained thereafter, an alternative antihypertensive agent may be used, with or without stopping clevidipine IV antihypertensive infusion. The alternative agent should be used per institutional treatment practice. During the initial 1 hour of the treatment period, however, clevidipine IV antihypertensive treatment should be administered as monotherapy until 1 hour post initiation of study drug. The use of an alternative antihypertensive agents is discouraged and limited to where medically necessary to maintain patient safety. 