In an 86‑year‑old woman with hypertension on lisinopril who presents to the emergency department with asymptomatic, markedly elevated blood pressure, should lisinopril be switched to amlodipine?

Do Not Switch to Amlodipine Monotherapy

In an 86-year-old woman presenting to the ER with asymptomatic severe hypertension (205/104 mmHg) on lisinopril, you should NOT switch to amlodipine monotherapy; instead, add amlodipine to her existing lisinopril and initiate a thiazide-type diuretic to create triple therapy, as this patient has hypertensive urgency requiring gradual outpatient intensification, not medication substitution. 1

Critical Distinction: Urgency vs Emergency

• This patient has hypertensive urgency (BP >180/120 mmHg without acute target-organ damage), not a hypertensive emergency, which means IV agents are contraindicated and oral therapy with gradual BP reduction is the standard of care 1, 2
• Asymptomatic severe hypertension should never be treated aggressively in the ER—rapid BP lowering increases the risk of stroke, myocardial infarction, and acute kidney injury 1, 2
• The absence of symptoms (chest pain, dyspnea, altered mental status, visual changes, severe headache) confirms this is urgency, not emergency 1, 2

Why Switching is the Wrong Approach

• Monotherapy failure is expected: In the ALLHAT trial, only 28% of patients on chlorthalidone, 24% on amlodipine, and 24% on lisinopril achieved BP control (<140/90 mmHg) with monotherapy alone 3
• The 2024 ESC Guidelines explicitly recommend initiating combination therapy with two or preferably three first-line agents when BP is >20/10 mmHg above target 2
• This patient's BP of 205/104 mmHg is 65/14 mmHg above the target of <140/90 mmHg for an 86-year-old, making triple therapy the evidence-based standard 2

Recommended Treatment Algorithm

Immediate ER Management

• Do NOT use IV antihypertensives—these are reserved exclusively for hypertensive emergencies with acute target-organ damage 1, 2
• Initiate oral antihypertensive intensification with a target BP reduction of no more than 25% within the first hour, then aim for <160/100 mmHg over 2-6 hours 1
• Observe for at least 2 hours to evaluate BP-lowering efficacy and safety 1

Optimal Medication Regimen

Add two agents to her existing lisinopril:

• Continue lisinopril (current dose, likely 10-40 mg daily based on ALLHAT dosing) 3
• Add amlodipine 5 mg daily (dihydropyridine calcium channel blocker) 2
• Add chlorthalidone 6.25-12.5 mg daily (thiazide-type diuretic, preferred over hydrochlorothiazide due to longer half-life and superior cardiovascular outcomes) 2

Rationale for Triple Therapy

• The combination of ACE inhibitor + calcium channel blocker + thiazide-type diuretic targets three complementary mechanisms: renin-angiotensin system blockade, vasodilation, and volume reduction 2
• In ALLHAT, the mean number of drugs required to achieve BP control was 1.9-2.1, with the majority requiring multidrug therapy 3
• The lisinopril arm in ALLHAT showed higher rates of stroke (RR 1.15) and combined cardiovascular disease (RR 1.10) compared to chlorthalidone, supporting the addition of a diuretic 4

Why Not Switch to Amlodipine Alone

• Amlodipine monotherapy is inadequate: In ALLHAT, amlodipine achieved only 66% BP control at 5 years with a mean of 2.0 drugs prescribed 3
• Lisinopril provides complementary benefits: ACE inhibitors offer renal protection and reduce cardiovascular events, particularly important in elderly patients 4
• Switching wastes time: The patient has already been on lisinopril, and switching to another monotherapy will delay achieving BP control 2

Special Considerations for an 86-Year-Old

• The 2024 ESC Guidelines recommend treating patients aged <85 years who are not moderately to severely frail with the same targets as younger patients, provided treatment is well tolerated 4
• Screen for orthostatic hypotension before intensifying therapy: measure BP after 5 minutes of sitting/lying, then 1 and/or 3 minutes after standing 4
• If the patient is frail or aged ≥85 years, consider starting with lower doses and titrating more cautiously, but still aim for triple therapy if tolerated 4
• Long-acting dihydropyridine calcium channel blockers (amlodipine) and RAS inhibitors (lisinopril) are preferred in frail elderly patients, followed by low-dose diuretics 4

Dose Titration Plan

• Reassess BP within 2-4 weeks after initiating triple therapy 2
• If BP remains >140/90 mmHg, uptitrate to:
  • Lisinopril 20-40 mg daily 3
  • Amlodipine 10 mg daily 2
  • Chlorthalidone 12.5-25 mg daily 2
• Goal: achieve target BP <140/90 mmHg (ideally <130/80 mmHg if well tolerated) within 3 months 2

Follow-Up Strategy

• Schedule outpatient follow-up within 1-7 days after ER discharge 1
• Then monthly visits until target BP is achieved 1
• Address medication adherence, as non-compliance is the most common trigger for hypertensive urgencies 1, 2
• Approximately one-third of patients with elevated BP in the ER normalize spontaneously before follow-up, so close monitoring is essential 1

Critical Pitfalls to Avoid

• Never use short-acting nifedipine—it causes unpredictable, rapid BP drops associated with stroke and death 1, 2
• Never admit for asymptomatic hypertension—intensive inpatient BP management is not associated with improved outcomes and may cause harm 1
• Never lower BP rapidly in chronic hypertensives—altered cerebral autoregulation predisposes to ischemic injury 2
• Never use IV agents for hypertensive urgency—oral therapy is safer and equally effective 1, 2

Evidence Supporting Combination Therapy

• The ALLHAT study demonstrated that chlorthalidone was superior to lisinopril in preventing stroke (RR 1.15 for lisinopril vs chlorthalidone) and combined cardiovascular disease (RR 1.10), supporting the addition of a diuretic to ACE inhibitor therapy 4
• The combination of amlodipine + valsartan (similar to amlodipine + lisinopril) achieved BP control in 79.7% of patients with stage 2 hypertension at 6 weeks, compared to 77.3% with lisinopril + HCTZ 5
• Fixed-dose combinations of ACE inhibitors + calcium channel blockers improve adherence: ramipril + amlodipine had 54% one-year persistence vs 36% for lisinopril + amlodipine, though both combinations are effective 6