<prompt> All the following agents may be used in the treatment of Aoic dissection , exceptPropranololDiazoxideNa nitroprussideLabetalol  <response>: Ref Harrison 19 th ed pg 1641 For acute dissection, unless contraindicated, b-adrenergic blockers should be administered par- enterally, using intravenous propranolol, metoprolol, or the sho- acting esmolol to achieve a hea rate of approximately 60 beats min. This should be accompanied by sodium nitroprusside infusion to lower systolic blood pressure to 120 mmHg. Labetalol a drug with both b- and a-adrenergic blocking propeies, also may be used as a parenteral agent in acute therapy for dissection. 