A 79-year-old patient on amlodipine 5 mg daily has a blood pressure of 150/60 mm Hg and headache; should we add enalapril (Envas) 2.5 mg once daily?

Management of Uncontrolled Hypertension in a 79-Year-Old on Amlodipine

Before adding enalapril, first optimize the amlodipine dose to 10 mg daily and confirm that the blood pressure elevation is persistent through home monitoring; if BP remains ≥150/90 mmHg after 2–4 weeks, then add enalapril 2.5 mg daily to achieve guideline-recommended dual therapy. 1

Initial Assessment and Dose Optimization

Confirm True Hypertension

• Verify the 150/60 mmHg reading with home blood pressure monitoring (≥135/85 mmHg confirms hypertension) or 24-hour ambulatory monitoring (≥130/80 mmHg) to exclude white-coat hypertension before intensifying therapy. 1
• The headache may be unrelated to blood pressure or may reflect inadequate control; however, headache alone is not a reliable indicator of hypertension severity. 1

Optimize Current Amlodipine Therapy First

• Increase amlodipine from 5 mg to 10 mg once daily as the immediate next step, because amlodipine demonstrates a clear dose-response relationship with mean systolic reductions of 17.5 mmHg at therapeutic doses. 2, 3
• Amlodipine 10 mg provides superior 24-hour blood pressure control compared to 5 mg, with the drug's 40–60 hour half-life ensuring smooth coverage without significant peak-trough fluctuation (20–25% variation). 4, 5
• Re-measure blood pressure 2–4 weeks after dose escalation, as amlodipine reaches steady-state over 1–1.5 weeks and blood pressure reduction occurs gradually over 4–8 hours after each dose. 4, 6

Adding Enalapril (Second-Line Therapy)

When to Add Enalapril

• If systolic BP remains ≥150 mmHg after 2–4 weeks on amlodipine 10 mg, add enalapril 2.5 mg once daily to create guideline-recommended dual therapy (ACE inhibitor + calcium-channel blocker). 1
• For adults aged ≥60 years, the ACP/AAFP guidelines (strong recommendation, high-quality evidence) recommend treating to a target systolic BP <150 mmHg to reduce mortality, stroke, and cardiac events. 1
• The combination of amlodipine with an ACE inhibitor provides complementary mechanisms—vasodilation through calcium-channel blockade plus renin-angiotensin system inhibition—and has demonstrated superior blood pressure control compared to either agent alone. 7

Dosing and Titration Strategy

• Start enalapril at 2.5 mg once daily (appropriate low dose for a 79-year-old), then titrate to 5–10 mg daily after 2–4 weeks if BP remains above target and the drug is well tolerated. 7
• The combination may also reduce amlodipine-related peripheral edema, a common side effect that occurs in elderly patients. 7

Blood Pressure Targets for This Patient

Age-Appropriate Goals

• Primary target: systolic BP <150 mmHg (strong recommendation for adults ≥60 years without prior stroke/TIA or high cardiovascular risk). 1
• Consider a lower target of <140 mmHg only if the patient has a history of stroke/TIA (weak recommendation, moderate-quality evidence) or is at high cardiovascular risk based on individualized assessment (weak recommendation, low-quality evidence). 1
• The wide pulse pressure (150/60 mmHg = 90 mmHg pulse pressure) reflects arterial stiffness common in elderly patients; focus on systolic control while avoiding excessive diastolic lowering below 60 mmHg. 1

Monitoring After Adding Enalapril

Laboratory and Clinical Follow-Up

• Check serum potassium and creatinine 2–4 weeks after initiating enalapril to detect hyperkalemia or acute kidney injury, especially important in elderly patients. 7
• Monitor for ACE inhibitor-specific adverse effects: dry cough (most common, 5–20% incidence) and hyperkalemia. 1
• Re-assess blood pressure 2–4 weeks after adding enalapril, with the goal of achieving target BP <150/90 mmHg within 3 months of therapy modification. 1, 7

If Blood Pressure Remains Uncontrolled on Dual Therapy

Third-Line Agent

• If BP remains ≥150/90 mmHg after optimizing amlodipine 10 mg + enalapril 10 mg, add a thiazide-like diuretic (chlorthalidone 12.5–25 mg daily preferred, or hydrochlorothiazide 25 mg daily) to achieve guideline-recommended triple therapy. 7
• Chlorthalidone is preferred over hydrochlorothiazide due to superior 24-hour BP control and stronger cardiovascular outcome data. 7

Addressing the Headache

Differential Diagnosis

• Headache in the setting of BP 150/60 mmHg is unlikely to be directly caused by hypertension unless BP is severely elevated (≥180/110 mmHg). 1
• Amlodipine itself can cause headache (listed as a common adverse effect in 5–10% of patients), particularly during the first 2–4 weeks of therapy or after dose escalation. 1
• Evaluate for other causes: tension headache, migraine, medication overuse, cervical spine pathology, or temporal arteritis (especially important in a 79-year-old). 1
• If headache persists after BP control is achieved and other causes are excluded, consider switching from amlodipine to an alternative calcium-channel blocker or different drug class. 1

Critical Pitfalls to Avoid

Common Errors in Elderly Hypertension Management

• Do not add a second drug before optimizing the first—amlodipine 5 mg is a sub-therapeutic dose for many patients, and increasing to 10 mg may achieve target BP without polypharmacy. 7, 2
• Do not combine enalapril with an ARB (dual renin-angiotensin blockade), as this increases adverse events (hyperkalemia, acute kidney injury) without additional cardiovascular benefit. 1, 7
• Do not target BP <140/90 mmHg aggressively in all elderly patients—the evidence for benefit below 150 mmHg systolic is weak, and lower targets increase risks of hypotension, falls, and syncope. 1
• Do not add a beta-blocker as the second agent unless there are compelling indications (prior MI, heart failure, angina, atrial fibrillation), as beta-blockers are less effective than ACE inhibitors or diuretics for stroke prevention in uncomplicated hypertension. 7
• Do not delay treatment intensification if BP remains ≥150/90 mmHg after optimizing amlodipine—uncontrolled hypertension should be addressed within 2–4 weeks to reduce cardiovascular risk. 1, 7

Lifestyle Modifications (Adjunctive Measures)

Non-Pharmacologic Interventions

• Sodium restriction to <2 g/day yields a 5–10 mmHg systolic reduction and is particularly effective in elderly patients. 1, 7
• DASH dietary pattern (high in fruits, vegetables, whole grains, low-fat dairy; low in saturated fat) reduces BP by approximately 11.4/5.5 mmHg. 1, 7
• Regular aerobic exercise (≥30 minutes most days) lowers BP by about 4/3 mmHg, though intensity should be adjusted for age and comorbidities. 1, 7
• Weight loss (if BMI ≥25 kg/m²)—losing approximately 10 kg reduces BP by roughly 6/4.6 mmHg. 1, 7
• Limit alcohol to ≤1 drink/day for women or ≤2 drinks/day for men. 1, 7