Recent literature indicates that many patients with a true hypertensive emergency are mismanaged.
Patients with a hypertensive emergency should have an arterial line placed and receive a continuous infusion of a short-acting, titratable medication to reduce blood pressure. Avoid oral, sublingual, and intermittent IV bolus administration of antihypertensives.
Recall that most patients with a hypertensive emergency are volume depleted. Providing IV fluids can help to prevent marked drops blood pressure when you start an IV antihypertensive medication.
Avoid diuretics (due to volume depletion) and hydralazine. Hydralazine can cause precipitous drops in blood pressure and is felt by many to have no role in the treatment of hypertensive emergencies.
Marik PE, Rivera R. Hypertensive emergencies: an update. CurrOpinCrit Care 2011; 17:569-80.