What is a good first-line antihypertensive medication for a 72-year-old female with no significant medical history and stage 1 hypertension (blood pressure 140/84 mmHg)?

First-Line Antihypertensive for a 72-Year-Old Female with Stage 1 Hypertension

Start with a thiazide-like diuretic (chlorthalidone 12.5 mg daily) or a dihydropyridine calcium channel blocker (amlodipine 5 mg daily) as first-line therapy, with a slight preference for the thiazide-like diuretic based on the strongest mortality and stroke reduction data in elderly women. 1

Recommended Treatment Approach

Primary Option: Thiazide-Like Diuretic

• Chlorthalidone 12.5-25 mg daily is the preferred first-line agent based on proven cardiovascular outcomes and mortality reduction in elderly patients, particularly women 1, 2
• Low-dose thiazides specifically reduced coronary heart disease (RR 0.72), stroke (RR 0.63), cardiovascular events (RR 0.70), and all-cause mortality (RR 0.89) in randomized trials 3
• The SHEP trial, which included 63% women with mean age 72 years, demonstrated significant stroke reduction (5.5% vs 8.2% with placebo) when treating to SBP <140 mmHg 4
• Start with 12.5 mg daily to minimize electrolyte disturbances, as doses above this significantly increase hypokalemia risk 3-fold in elderly patients 5

Alternative Option: Calcium Channel Blocker

• Amlodipine 5 mg daily is an excellent alternative, particularly well-tolerated in elderly patients without causing bradycardia, salt retention, or postural hypotension 1, 6
• Dihydropyridine calcium channel blockers demonstrated marked reductions in cardiovascular morbidity and mortality in elderly patients with isolated systolic hypertension 4
• The European Society of Cardiology specifically recommends calcium channel blockers for patients ≥55 years as first-line therapy 5
• Amlodipine reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions 6

Blood Pressure Target

• Target BP <140/90 mmHg as the primary goal for this 72-year-old patient 4
• Treating to SBP <140 mmHg provides greater public health protection against cardiovascular disease in older women with little evidence of serious harm 4
• If well-tolerated and the patient has high cardiovascular risk, consider targeting <130/80 mmHg 5
• The current BP of 140/84 mmHg represents stage 1 hypertension requiring pharmacologic intervention 2

Treatment Algorithm

Step 1: Initial Monotherapy

• Start chlorthalidone 12.5 mg daily OR amlodipine 5 mg daily 1
• Check blood pressure, renal function, and electrolytes (if using thiazide) at 1-2 weeks after initiation 1, 7

Step 2: Reassessment at 4-6 Weeks

• If BP remains ≥140/90 mmHg, increase chlorthalidone to 25 mg daily OR amlodipine to 10 mg daily 1
• Recheck blood pressure within 2-4 weeks after dose adjustment 1

Step 3: Add Second Agent if Needed

• If monotherapy at maximum dose fails to achieve target, add a medication from a different class 1
• Preferred combination: thiazide + calcium channel blocker OR thiazide + ACE inhibitor/ARB 4
• Achieve target blood pressure control within 3 months of initiating therapy 5, 7

Critical Monitoring Considerations

• Always check blood pressure in both sitting and standing positions due to increased orthostatic hypotension risk in elderly patients 4
• Monitor potassium and creatinine at baseline and 1-2 weeks after starting thiazide diuretics 5
• Hypokalemia below 3.5 mEq/L eliminates cardiovascular protection and increases sudden death risk, making electrolyte monitoring essential 5
• Once BP is controlled and stable, monitor every 4-6 months 1

Why Not Other Drug Classes?

• Beta-blockers are inferior to thiazides and calcium channel blockers for stroke prevention and cardiovascular events in elderly patients without specific indications (prior MI, heart failure, active angina) 4, 2
• ACE inhibitors or ARBs should be reserved for patients with specific compelling indications such as diabetes, chronic kidney disease with albuminuria, or heart failure 4
• This patient has no compelling indications requiring ACE inhibitor/ARB as first-line therapy 4

Common Pitfalls to Avoid

• Do not use high-dose thiazides (>25 mg chlorthalidone) as they provide minimal additional BP reduction but substantially increase adverse effects, particularly hypokalemia requiring hospitalization 5
• Avoid starting with combination therapy in a patient with BP 140/84 mmHg; single-agent therapy is appropriate for BP between 130/80 and 160/100 mmHg 4
• Do not delay treatment based on age alone; this 72-year-old patient is well below the 80-year threshold where more conservative targets might be considered 4
• Start with low doses and titrate gradually in elderly patients due to greater chance of undesirable effects 4

Special Considerations for Elderly Women

• Women comprise the majority of the elderly hypertensive population and were well-represented in hypertension trials 4
• The Blood Pressure Lowering Treatment Trialists' Collaboration (87,349 women, mean age 63 years) concluded that all antihypertensive regimens were similar in protective effects against major cardiovascular events in women 4
• Treating elderly women to SBP <140 mmHg is strongly supported by observational studies showing a continuous and graded relationship between cardiovascular risk and increasing SBP 4