What is the appropriate next step to control blood pressure in a 55‑year‑old woman with hypertension who is currently taking atenolol 25 mg daily?

Blood Pressure Control for a 55-Year-Old Woman on Atenolol 25mg

Add a calcium-channel blocker (amlodipine 5–10 mg daily) or a thiazide-like diuretic (chlorthalidone 12.5–25 mg daily) as the second antihypertensive agent to achieve guideline-recommended dual therapy. 1, 2

Why Beta-Blocker Monotherapy Is Insufficient

• Atenolol 25 mg daily represents a low dose that is unlikely to provide adequate blood pressure control as monotherapy in most patients with hypertension. 3, 4
• While atenolol can be effective at 100–300 mg once daily, the maximum hypotensive effect typically occurs at 100 mg, and doses above this provide minimal additional benefit. 3
• Beta-blockers are not recommended as first-line agents for uncomplicated hypertension when there are no compelling indications (such as angina, recent myocardial infarction, heart failure with reduced ejection fraction, or atrial fibrillation). 1, 2
• Beta-blockers are less effective than calcium-channel blockers or thiazide diuretics for stroke prevention and overall cardiovascular event reduction in uncomplicated hypertension. 1, 5

Recommended Next Step: Add a Second Agent

Option 1: Calcium-Channel Blocker (Preferred for Most Patients)

• Add amlodipine 5 mg once daily, titrating to 10 mg if needed after 2–4 weeks. 1, 5
• The combination of a beta-blocker plus a calcium-channel blocker provides complementary mechanisms: heart rate and contractility reduction (atenolol) plus arterial vasodilation (amlodipine). 1
• This combination is particularly effective in middle-aged women and does not cause the metabolic side effects (glucose intolerance, lipid abnormalities) sometimes seen with higher-dose beta-blockers. 1, 5

Option 2: Thiazide-Like Diuretic

• Add chlorthalidone 12.5–25 mg once daily (preferred over hydrochlorothiazide due to longer duration of action and superior cardiovascular outcome data). 1, 6
• The combination of atenolol plus chlorthalidone has been studied and shown to produce significant blood pressure reductions, though the effect may be slightly less than additive. 7
• Start with 12.5–25 mg daily; doses above 25 mg significantly increase the risk of hypokalemia and provide minimal additional blood pressure reduction. 5, 6

Blood Pressure Targets and Monitoring

• Target blood pressure < 130/80 mmHg for most adults; at minimum < 140/90 mmHg. 1, 2
• Re-measure blood pressure 2–4 weeks after adding the second agent, with the goal of achieving target within 3 months. 1, 5
• Check serum potassium and creatinine 2–4 weeks after initiating a thiazide diuretic to detect hypokalemia or renal function changes. 1

If Blood Pressure Remains Uncontrolled on Dual Therapy

• Add a third agent from the remaining class to create triple therapy (beta-blocker + calcium-channel blocker + thiazide diuretic). 1
• If blood pressure remains ≥ 140/90 mmHg despite optimized triple therapy, add spironolactone 25–50 mg daily as the preferred fourth-line agent for resistant hypertension. 1, 2

Critical Steps Before Adding Medication

• Verify medication adherence first, as non-adherence is the most common cause of apparent treatment resistance. 1, 2
• Confirm true hypertension with home blood pressure monitoring (≥ 135/85 mmHg) or 24-hour ambulatory monitoring (≥ 130/80 mmHg) to exclude white-coat hypertension. 1, 2
• Review for interfering substances: NSAIDs, decongestants, oral contraceptives, systemic corticosteroids, and herbal supplements can all elevate blood pressure. 1

Lifestyle Modifications (Adjunct to Pharmacotherapy)

• Sodium restriction to < 2 g/day yields a 5–10 mmHg systolic reduction and enhances the efficacy of all antihypertensive classes. 1, 2
• Weight loss (approximately 10 kg for BMI ≥ 25 kg/m²) reduces blood pressure by ~6/4.6 mmHg (systolic/diastolic). 1, 2
• DASH dietary pattern (high in fruits, vegetables, whole grains, low-fat dairy; low in saturated fat) lowers blood pressure by roughly 11.4/5.5 mmHg. 1, 2
• Regular aerobic exercise (≥ 30 minutes most days, ≈ 150 minutes/week moderate intensity) reduces blood pressure by ≈ 4/3 mmHg. 1, 2
• Limit alcohol to ≤ 1 drink/day for women. 1, 2

Common Pitfalls to Avoid

• Do not simply increase atenolol dose without adding a second drug class, as combination therapy is more effective than monotherapy dose escalation. 1
• Do not combine atenolol with another beta-blocker, as this provides no additional benefit. 1
• Do not delay treatment intensification when blood pressure remains ≥ 140/90 mmHg; prompt action within 2–4 weeks is required to reduce cardiovascular risk. 1, 2
• Do not assume treatment failure without first confirming adherence and excluding secondary causes of hypertension. 1, 2