How to initiate antihypertensive therapy in an elderly patient with hypertension (blood pressure 160/90 mmHg)?

Initiating Antihypertensive Therapy in an Elderly Patient with BP 160/90 mmHg

Start antihypertensive medication immediately with a single low-dose agent—either amlodipine 5 mg daily or a low-dose thiazide-like diuretic (chlorthalidone 12.5 mg or hydrochlorothiazide 12.5 mg daily)—and titrate slowly over 4-8 weeks to achieve a target BP of 130-140/70-80 mmHg, with more lenient targets (140-150/90 mmHg) if the patient is frail or over 80 years old. 1, 2

Immediate Treatment Approach

Step 1: Confirm the Diagnosis and Start Therapy

• This patient has Grade 2 hypertension (≥160/100 mmHg systolic component) and requires immediate pharmacological treatment alongside lifestyle interventions. 1
• Do not delay treatment for 3-6 months of lifestyle modification alone, as this BP level warrants immediate drug therapy. 1

Step 2: Choose Initial Monotherapy

For elderly patients, monotherapy is preferred over dual therapy to minimize hypotension risk. 1

First-line options (choose one):

• Amlodipine 5 mg once daily (preferred if patient has no contraindications) 3, 4, 5
• Chlorthalidone 12.5 mg once daily or hydrochlorothiazide 12.5 mg once daily 1, 6, 7
• Lisinopril 10 mg daily or losartan 50 mg daily (if ACE inhibitor/ARB preferred) 1, 3

Rationale for monotherapy in elderly: The 2020 International Society of Hypertension guidelines specifically recommend considering monotherapy in patients aged >80 years or those who are frail, even with Grade 2 hypertension. 1 Starting with two drugs increases the risk of symptomatic hypotension and orthostatic hypotension in this population. 1

Drug Selection Algorithm

Choose Amlodipine 5 mg if:

• Patient has no reactive airway disease requiring beta-blockers 3
• Patient has concurrent angina or coronary artery disease 4
• Patient has concurrent hypercholesterolemia (amlodipine does not adversely affect lipid profiles) 3
• Elderly patients have 40-60% higher drug exposure due to decreased clearance, making the 5 mg starting dose appropriate 4

Choose Low-Dose Thiazide/Thiazide-Like Diuretic if:

• Patient has evidence of volume overload or heart failure 1
• Cost is a major concern (generic thiazides are inexpensive) 6, 7
• Use chlorthalidone 12.5 mg or hydrochlorothiazide 12.5 mg—NOT the older high doses of 25-50 mg—to minimize hypokalemia and metabolic side effects 6, 8, 7

Choose ACE Inhibitor/ARB if:

• Patient has diabetes, chronic kidney disease, or proteinuria 1
• Patient has heart failure with reduced ejection fraction 1
• Monitor serum creatinine and potassium 1-2 weeks after initiation 3

Blood Pressure Targets Based on Age and Frailty

For patients 65-79 years old (non-frail):

• Target: 130-140/70-80 mmHg 2
• The 2020 ISH guidelines recommend individualizing for elderly based on frailty, with a minimum reduction of 20/10 mmHg. 1

For patients ≥80 years old or frail:

• Target: 140-150/90 mmHg 2
• Do not reduce diastolic BP below 60 mmHg as this may compromise coronary perfusion. 2
• The HYVET trial demonstrated cardiovascular benefit in patients >80 years with on-treatment systolic BP that remained 140-150 mmHg. 2

Critical Caveat:

Assess for frailty before setting targets. Frail elderly patients should have more lenient targets (140-150/90 mmHg) regardless of chronological age to avoid falls, syncope, and orthostatic hypotension. 1, 2

Titration Strategy

Week 0-4:

• Start with chosen low-dose monotherapy 1, 4
• Monitor BP weekly (home BP monitoring preferred) to detect excessive drops 1
• Screen for orthostatic hypotension at every visit (measure BP supine and after 1-3 minutes standing) 2

Week 4-8:

• If BP remains >140/90 mmHg (or >150/90 if ≥80 years old), increase to full dose of initial agent 1
  • Amlodipine: increase to 10 mg daily 4, 5
  • Chlorthalidone: increase to 25 mg daily 6, 7
  • Hydrochlorothiazide: increase to 25 mg daily 8, 7
  • Lisinopril: increase to 20 mg daily 3
  • Losartan: increase to 100 mg daily 3

Week 8-12:

• If BP still not at target on maximum monotherapy dose, add a second agent from a different class 1
• Preferred combinations:
  • Amlodipine + ACE inhibitor/ARB 1, 3
  • Amlodipine + thiazide diuretic 1
  • ACE inhibitor/ARB + thiazide diuretic 1

Target Achievement:

• Aim to achieve target BP within 3 months 1, 2
• If target not achieved on two drugs, add a third agent (typically spironolactone 25 mg daily if no contraindications) 1

Critical Pitfalls to Avoid

Do NOT:

• Start with two drugs simultaneously in elderly patients (increases hypotension risk) 1
• Use high-dose thiazides (HCTZ 50 mg or chlorthalidone 50 mg) as these cause significant hypokalemia and metabolic disturbances without additional BP benefit 6, 8, 7
• Target BP <130/80 mmHg aggressively in patients ≥80 years or frail (increases fall risk and adverse events) 2
• Reduce diastolic BP below 60 mmHg (compromises coronary perfusion) 2
• Use beta-blockers as first-line unless there is a compelling indication like post-MI or heart failure with reduced ejection fraction 1

DO:

• Titrate slowly over 4-week intervals to allow full drug effect and avoid precipitous BP drops 4, 7
• Check orthostatic vital signs at every visit 2
• Monitor electrolytes (potassium, sodium) and renal function 1-2 weeks after starting diuretics or ACE inhibitors/ARBs 3, 8
• Simplify regimen with once-daily dosing to improve adherence 1
• Consider single-pill combination products once dual therapy is established to improve adherence 1

Monitoring Parameters

Initial 3 months (until target achieved):

• BP monitoring every 2-4 weeks (home BP preferred: target <135/85 mmHg) 1
• Orthostatic BP at every visit 2
• Serum creatinine, potassium, sodium at 1-2 weeks after starting ACE inhibitor/ARB or diuretic 3, 8

After target achieved:

• BP monitoring every 3-6 months 1
• Annual metabolic panel (electrolytes, creatinine, glucose) 8
• Assess for medication adherence and side effects 1