What are antihypertensives given Intravenous(IV)?

From the Guidelines

Intravenous (IV) antihypertensives are typically used in hypertensive emergencies, and the most commonly used agents include nicardipine, labetalol, sodium nitroprusside, fenoldopam, esmolol, phentolamine, hydralazine, and enalaprilat 1.

Classes of IV Antihypertensives

• Calcium Channel Blockers (CCBs):
  • Nicardipine: initial dose 5 mg/h, increasing every 5 min by 2.5 mg/h to maximum 15 mg/h 1
  • Clevidipine: initial dose 1–2 mg/h, doubling every 90 s until BP approaches target, then increasing by less than double every 5–10 min; maximum dose 32 mg/h; maximum duration 72 h 1
• Vasodilators:
  • Sodium nitroprusside: initial dose 0.3–0.5 mcg/kg/min; increase in increments of 0.5 mcg/kg/min to achieve BP target; maximum dose 10 mcg/kg/min; duration of treatment as short as possible 1
  • Nitroglycerin: initial dose 5 mcg/min; increase in increments of 5 mcg/min every 3–5 min to a maximum of 20 mcg/min 1
  • Hydralazine: initial dose 10 mg via slow IV infusion (maximum initial dose 20 mg); repeat every 4–6 h as needed 1
• Adrenergic Blockers:
  • Esmolol: loading dose 500–1000 mcg/kg/min over 1 min followed by a 50-mcg/kg/min infusion. For additional dosing, the bolus dose is repeated and the infusion increased in 50-mcg/kg/min increments as needed to a maximum of 200 mcg/kg/min 1
  • Labetalol: initial dose 0.3–1.0-mg/kg dose (maximum 20 mg) slow IV injection every 10 min or 0.4–1.0-mg/kg/h IV infusion up to 3 mg/kg/h. Adjust rate up to total cumulative dose of 300 mg. This dose can be repeated every 4–6 h 1
  • Phentolamine: IV bolus dose 5 mg. Additional bolus doses every 10 min as needed to lower BP to target 1
• Dopamine-Receptor Selective Agonist:
  • Fenoldopam: initial dose 0.1–0.3 mcg/kg/min; may be increased in increments of 0.05–0.1 mcg/kg/min every 15 min until target BP is reached. Maximum infusion rate 1.6 mcg/kg/min 1
• ACE Inhibitor:
  • Enalaprilat: initial dose 1.25 mg over a 5-min period. Doses can be increased up to 5 mg every 6 h as needed to achieve BP target 1 These agents are used to rapidly lower blood pressure in patients with hypertensive emergencies, and the choice of agent depends on the specific clinical context and the presence of any contraindications 1.

From the Research

Antihypertensives Given Intravenous (IV)

The following antihypertensive agents are given intravenously (IV) for the treatment of hypertensive emergencies:

• Nicardipine
• Nitroprusside
• Fenoldopam
• Nitroglycerin
• Enalaprilat
• Hydralazine
• Labetalol
• Esmolol
• Phentolamine
• Clevidipine 2

Selection of IV Antihypertensives

The selection of a specific IV antihypertensive agent should be based on the agent's pharmacology and patient-specific factors, such as comorbidity and the presence of end-organ damage 2. For example, IV nicardipine has been shown to be effective in the short-term reduction of blood pressure in patients with severe or postoperative hypertension, and has a potential role in the intraoperative acute control of blood pressure in patients undergoing various surgical procedures 3.

Use of IV Antihypertensives in Clinical Settings

IV antihypertensives are used in various clinical settings, including:

• Hypertensive emergencies
• Postoperative hypertension
• Intraoperative acute control of blood pressure
• Acute intracerebral haemorrhage
• Acute ischaemic stroke
• Pre-eclampsia
• Acute aortic dissection
• Premature labour
• Electroconvulsive therapy 3, 4

Appropriate Use of IV Antihypertensives

The use of IV antihypertensives should be reserved for patients with symptomatic blood pressure elevation or those with evidence of end-organ damage 5. In patients with asymptomatic blood pressure elevation, oral agents should be used to slowly decrease blood pressure, rather than IV antihypertensives 5.