What intravenous (IV) medication can be given for acute hypertension that won't decrease heart rate, other than hydralazine?

IV Medications for Acute Hypertension Without Decreasing Heart Rate

Nicardipine and clevidipine are the preferred IV medications for acute hypertension that won't decrease heart rate, with fenoldopam being another excellent option. 1

First-Line Options

Nicardipine

• Mechanism: Calcium channel blocker (dihydropyridine) that inhibits calcium ion influx 2
• Dosing:
  • Initial: 5 mg/h IV
  • Titration: Increase by 2.5 mg/h every 5 minutes
  • Maximum: 15 mg/h 1
• Advantages:
  • Minimal effect on heart rate
  • No dose adjustment needed for elderly
  • Reliable blood pressure reduction 1

Clevidipine

• Mechanism: Ultra-short-acting dihydropyridine calcium channel blocker
• Dosing:
  • Initial: 1-2 mg/h IV
  • Titration: Double dose every 90 seconds initially, then adjust more gradually
• Advantages:
  • Rapid onset and offset
  • Arterial-selective vasodilation
  • Minimal effect on heart rate 1

Fenoldopam

• Mechanism: Selective dopamine-1 receptor agonist
• Dosing:
  • Initial: 0.1-0.3 mcg/kg/min IV
  • Maximum: 1.6 mcg/kg/min 1
• Advantages:
  • Maintains renal perfusion
  • No reflex tachycardia
  • Causes diuresis and natriuresis 3
  • Effective in patients with renal disease 4

Medications to Avoid

Beta-Blockers (Esmolol, Labetalol)

• Contraindicated when maintaining heart rate is a priority 1
• Labetalol has combined alpha and beta blockade effects, but will still lower heart rate 1

Sodium Nitroprusside

• Should be avoided due to:
  • Risk of cyanide toxicity
  • Significant toxicities 5
  • Should be used with caution in patients with impaired cerebral flow 6

Hydralazine

• Not recommended as first-line therapy due to:
  • Unpredictable response
  • Prolonged duration of action
  • Primarily used in eclampsia/preeclampsia 1, 6

Clinical Considerations

Monitoring

• Continuous blood pressure monitoring is essential during administration
• Target reduction: Mean arterial pressure by 20-25% within several hours 1
• Condition-specific targets vary (e.g., aortic dissection requires more aggressive lowering) 1

Transition to Oral Therapy

• Begin oral antihypertensives 1 hour before discontinuing IV medications
• This ensures smooth transition and prevents rebound hypertension 1

Special Populations

• Renal impairment: Fenoldopam may be particularly beneficial due to its renal-protective effects 3, 4
• Cardiac patients: Nicardipine is a potent arteriolar vasodilator without significant direct depressant effect on myocardium 6

Common Pitfalls

• Avoid too rapid reduction in blood pressure, which can lead to organ hypoperfusion
• Don't use nifedipine, nitroglycerin, or hydralazine as first-line agents due to associated toxicities and adverse effects 5
• Beware of rebound hypertension when discontinuing IV medications without proper oral medication transition 1

In summary, for acute hypertension management requiring preservation of heart rate, nicardipine and clevidipine are the preferred agents, with fenoldopam being an excellent alternative, especially in patients with renal concerns.