Table 3: Management of Hypertensive Urgencies: Oral Agents

Table 3:
Management of Hypertensive Emergencies
Agent	Dose	Onset/Duration of Action (after discontinuation)	Precautions
Parenteral Vasodilators
Sodium nitroprusside	0.25-10 µg/kg/min as IV infusion	Immediate/2-3 min after infusion	Nausea, vomiting; with prolonged use may cause thiocyanate intoxication, methemoglobinemia, acidosis, cyanide poisoning; bags, bottles, and delivery sets must be light resistant
Nitroglycerin	5-100 µg as IV infusion*	2-5 min/5-10 min	Headache, tachycardia, vomiting, flushing, methemoglobinemia; requires special delivery system due to drug binding to PVC tubing
Nicardipine	5-15 mg/hr IV infusion	1-5 min/15-30 min, but may exceed 12 hr after prolonged infusion	Tachycardia, nausea, vomiting, headache, increased intracranial pressure; hypotension may be protracted after prolonged infusions
Diazoxide	50-150 mg as IV bolus, repeated or 15-30 mg/min by IV infusion	2-5 min/3-12 hr	Hypotension, tachycardia, aggravation of angina pectoris, nausea and vomiting, hyperglycemia with repeated injections
Fenoldapam mesylate	0.1-0.3 µg/kg/min IV infusion	<5 min/30 min	Headache, tachycardia, flushing, local phlebitis, dizziness
Hydralazine	5-20 mg as IV bolus or 10-40 mg IM; repeat every 4-6 hr	10 min IV/>1hr (IV) 20-30 min IM/4-6 hr (IM)	Tachycardia, headache, vomiting, aggravation of angina pectoris, sodium & water retention and increased intracranial pressure
Enalaprilat	0.625-1.25 mg every 6 hr IV	Within 30 min/12-24 hr	Renal failure in patients with bilateral renal artery stenosis, hypotension
Parenteral Adrenergic Inhibitors
Labetalol	20-40 mg as IV bolus every 10 min; up to 2 mg/min as IV infusion	5-10 min/2-6 hr	Bronchoconstriction, heart block, orthostatic hypotension, bradycardia
Esmolol	500 µg/kg bolus injection IV or 50-100 µg/kg/min by infusion. May repeat bolus after 5 min or increase infusion rate to 300 µg/kg/min	1-5 min/15-30 min	First-degree heart block, congestive heart failure, asthma
Phentolamine	5-10 mg as IV bolus	1-2 min/10-30 min	Tachycardia, orthostatic hypotension
* Requires special delivery system hr=hour(s); min=minute; IV=intravenous; IM=intramuscular; PVC=polyvinyl chloride

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