What is the treatment for malignant hypertension?

Treatment of Malignant Hypertension

Malignant hypertension requires immediate blood pressure reduction with intravenous medications to prevent progression of target organ damage, with a goal of reducing mean arterial pressure by 20-25% within several hours. 1

Definition and Diagnosis

• Malignant hypertension is a hypertensive emergency characterized by severe blood pressure elevation (usually >200/120 mmHg) with acute hypertension-mediated organ damage, particularly advanced retinopathy 2
• Diagnostic criteria include bilateral flame-shaped hemorrhages, cotton wool spots (Grade III retinopathy), with or without papilledema (Grade IV retinopathy) 3, 2
• Target organ damage may involve the heart, retina, brain, kidneys, and large arteries 3

Initial Management

• Patients with malignant hypertension should be admitted for close monitoring and treatment with intravenous BP-lowering agents 1
• Blood pressure should be reduced by 20-25% within several hours, avoiding excessive or rapid reductions which can lead to organ underperfusion 1
• Continuous BP monitoring is essential during the acute phase 1

First-Line Medications

• Labetalol is recommended as first-line intravenous therapy for malignant hypertension 1
• Nicardipine is an effective alternative, administered by slow continuous infusion at a concentration of 0.1 mg/mL 1, 4
  • Initial infusion rate: 5 mg/hr
  • Titration: Increase by 2.5 mg/hr every 15 minutes (for gradual reduction) or every 5 minutes (for more rapid reduction)
  • Maximum rate: 15 mg/hr 4
  • Advantages: May be beneficial in preserving tissue perfusion in patients with ischemic disorders 5

Alternative Medications

• Sodium nitroprusside can be used but requires careful monitoring due to risk of toxicity 1
• Urapidil is another alternative agent mentioned in European guidelines 1
• Clevidipine, an ultra-short acting calcium-channel blocker, may be used but availability is limited 1
• Fenoldopam, a selective dopamine receptor agonist, offers the advantage of improving renal blood flow and causing natriuresis 5

Special Considerations

• In patients with autonomic hyperreactivity, treatment with benzodiazepines should be initiated first 1
• For patients with coronary ischemia, nitroglycerin and aspirin are recommended in addition to BP management 1
• In patients with pheochromocytoma, avoid labetalol as it may accelerate hypertension; use phentolamine, nitroprusside, or urapidil instead 1, 5
• For patients with acute aortic dissection, beta-blockers are the drug of choice with a target systolic BP <120 mmHg after 20 minutes 6
• Hydralazine remains the drug of choice for treatment of eclampsia 5

Transition to Oral Therapy

• After initial stabilization with IV medications, transition to oral antihypertensive therapy should be initiated 1, 4
• For nicardipine, when switching to oral therapy, administer the first dose 1 hour prior to discontinuation of the infusion 4
• ACE inhibitors should be started at very low doses to prevent sudden decreases in BP, as patients are often volume depleted due to pressure natriuresis 1, 7

Long-Term Management

• Patients who have experienced malignant hypertension remain at high risk of cardiovascular and renal disease 1
• BP control and amount of proteinuria during follow-up are the main risk factors for renal survival 1
• Improving medication adherence is crucial, as non-adherence is a common precipitating factor 1, 8
• Renin-angiotensin system blockers appear to be the cornerstone of long-term treatment 7

Prognosis

• Without treatment, the survival rate for malignant hypertension is only 10% to 35% 9
• With appropriate treatment, the 5-year survival rate improves to approximately 75% 9
• Renal survival at 5 years with modern treatment approaches is approximately 90% 7