What is the first‑line oral antihypertensive for an adult with hypertensive urgency (blood pressure ≥180 mm Hg systolic or ≥120 mm Hg diastolic) without evidence of acute target‑organ damage and no contraindications?

First-Line Oral Antihypertensive for Hypertensive Urgency

For an adult with hypertensive urgency (BP ≥180/120 mmHg without acute target-organ damage), captopril 12.5–25 mg orally is the preferred first-line agent, with extended-release nifedipine 30–60 mg as an acceptable alternative; immediate-release nifedipine must never be used due to risk of precipitous drops, stroke, and death. 1, 2

Critical Distinction: Emergency vs. Urgency

Before selecting any medication, you must rapidly confirm the absence of acute target-organ damage within minutes of presentation. 1

• Hypertensive urgency = BP ≥180/120 mmHg WITHOUT acute organ damage; managed with oral agents and outpatient follow-up. 1, 3
• Hypertensive emergency = BP ≥180/120 mmHg WITH acute organ damage (altered mental status, chest pain, acute MI, pulmonary edema, stroke, acute kidney injury, papilledema); requires ICU admission and IV therapy. 1, 3

The presence or absence of target-organ damage—not the absolute BP number—determines management. 1

Focused Assessment for Target-Organ Damage

Perform a rapid, focused examination to exclude emergency: 1

• Neurologic: altered mental status, severe headache with vomiting, visual disturbances, seizures, focal deficits (suggests hypertensive encephalopathy or stroke). 1, 3
• Cardiac: chest pain, dyspnea with pulmonary edema (suggests acute coronary syndrome or left-ventricular failure). 1, 4
• Fundoscopic: bilateral retinal hemorrhages, cotton-wool spots, or papilledema (malignant hypertension). 1
• Renal: acute rise in creatinine, oliguria (acute kidney injury). 1, 4

If any of these are present, this is a hypertensive emergency requiring immediate ICU transfer and IV therapy—oral agents are contraindicated. 1

First-Line Oral Agents for Hypertensive Urgency

Once you have confirmed the absence of acute target-organ damage, initiate oral therapy: 1

Captopril (ACE Inhibitor) – Preferred First-Line

• Dose: 12.5–25 mg orally. 1, 2
• Mechanism: Reduces afterload via angiotensin-converting enzyme inhibition. 2
• Advantages: Rapid onset (15–30 minutes), predictable effect, well-studied in urgency. 1, 5
• Critical caution: Risk of abrupt BP fall in volume-depleted patients (common after pressure natriuresis in malignant hypertension); start with the lower dose (12.5 mg) if volume depletion is suspected. 1
• Contraindications: Pregnancy (absolutely contraindicated), bilateral renal artery stenosis, hyperkalemia. 1

Extended-Release Nifedipine (Calcium-Channel Blocker) – Acceptable Alternative

• Dose: 30–60 mg orally. 1
• Mechanism: Dihydropyridine calcium-channel blocker causing arterial vasodilation. 1
• Advantages: Effective, well-tolerated, no risk of hyperkalemia. 1, 5
• Critical warning: Immediate-release nifedipine must never be used in hypertensive urgency or emergency due to unpredictable precipitous BP drops that can cause stroke and death. 1, 6, 7, 8

Labetalol (Combined α/β-Blocker) – Third-Line Oral Option

• Dose: 200–400 mg orally. 1
• Advantages: Dual mechanism (alpha and beta blockade), useful if tachycardia is present. 1
• Contraindications: Reactive airway disease, COPD, heart block, bradycardia, decompensated heart failure. 1, 4

Blood-Pressure Reduction Strategy

• Goal: Gradual reduction over 24–48 hours to ≤160/100 mmHg, then normalize over subsequent days. 1, 3
• Do NOT rapidly lower BP in hypertensive urgency—this may precipitate cerebral, renal, or coronary ischemia in patients with chronic hypertension who have altered autoregulation. 1, 9
• Patients can be discharged even if BP remains >180/110 mmHg if there is no evidence of acute target-organ damage and oral therapy is initiated. 1

Observation and Follow-Up

• Observe the patient for at least 2 hours after medication administration to assess efficacy and safety. 1
• Arrange outpatient follow-up within 2–4 weeks; target BP <130/80 mmHg (or <140/90 mmHg in elderly/frail) within 3 months. 1
• Up to one-third of patients with diastolic BP >95 mmHg normalize before follow-up without intervention. 1

Critical Pitfalls to Avoid

• Do NOT admit patients with asymptomatic severe hypertension without target-organ damage—this is urgency, not emergency. 1
• Do NOT use IV agents for hypertensive urgency; oral therapy is appropriate and safer. 1
• Do NOT use immediate-release nifedipine—it causes unpredictable precipitous drops, stroke, and death. 1, 6, 7, 8
• Do NOT rapidly lower BP in urgency—gradual reduction over 24–48 hours is essential to prevent ischemic complications. 1, 9
• Do NOT use hydralazine as first-line due to unpredictable response and prolonged duration. 1

Post-Stabilization Considerations

• Address medication non-adherence—the most common trigger for hypertensive crises. 1
• Screen for secondary causes (renal artery stenosis, pheochromocytoma, primary aldosteronism) after stabilization, as 20–40% of malignant hypertension cases have identifiable etiologies. 1, 3