What is the next best step for a black male patient with uncontrolled hypertension, currently on amlodipine (calcium channel blocker), who continues to have elevated blood pressure readings?

Next Step for Uncontrolled Hypertension in Black Male on Amlodipine

Add a thiazide-type diuretic (chlorthalidone 12.5-25 mg daily or hydrochlorothiazide 25-50 mg daily) to the current amlodipine regimen, as this combination is specifically recommended for Black patients and provides superior blood pressure control through complementary mechanisms of vasodilation and volume reduction. 1, 2

Rationale for Thiazide Diuretic Addition

For Black patients with uncontrolled hypertension on a calcium channel blocker, adding a thiazide diuretic is the preferred next step over adding an ACE inhibitor or ARB. 1, 2 The 2017 ACC/AHA guidelines explicitly state that in Black patients, thiazide-type diuretics and calcium channel blockers are more effective in lowering blood pressure and reducing cardiovascular events than renin-angiotensin system (RAS) inhibitors when used as monotherapy or in combination. 1

• The combination of amlodipine plus a thiazide diuretic is particularly effective in Black patients, providing greater blood pressure reductions than amlodipine plus an ACE inhibitor/ARB combination. 1, 2
• Chlorthalidone is preferred over hydrochlorothiazide due to its longer duration of action and superior cardiovascular outcomes data, with recommended dosing of 12.5-25 mg daily (compared to 25-50 mg daily for hydrochlorothiazide). 1, 2

Alternative: ACE Inhibitor or ARB

While a thiazide diuretic is preferred for Black patients, adding an ACE inhibitor or ARB remains a reasonable alternative that provides complementary blood pressure control through RAS blockade. 1, 2

• The combination of amlodipine with an ACE inhibitor or ARB produces similar blood pressure lowering in Black patients as in other racial groups. 1
• ACE inhibitors/ARBs should be prioritized if the patient has compelling indications such as chronic kidney disease, heart failure, diabetes with nephropathy, or coronary artery disease. 1, 2
• Black patients have a greater risk of angioedema with ACE inhibitors, which should be considered when selecting therapy. 1

Monitoring and Follow-Up

• Target blood pressure is <140/90 mmHg minimum, ideally <130/80 mmHg for higher-risk patients. 1, 2
• Reassess blood pressure within 2-4 weeks after adding the second agent, with the goal of achieving target blood pressure within 3 months of treatment modification. 2, 3
• When adding a thiazide diuretic, monitor serum potassium and creatinine 2-4 weeks after initiation to detect potential hypokalemia or changes in renal function. 2

If Blood Pressure Remains Uncontrolled on Dual Therapy

Add the third drug class (either an ACE inhibitor/ARB if thiazide was added second, or a thiazide if ACE inhibitor/ARB was added second) to achieve guideline-recommended triple therapy. 1, 2

• Most Black patients with hypertension require ≥2 antihypertensive medications to achieve adequate blood pressure control. 1
• The combination of calcium channel blocker + thiazide diuretic + ACE inhibitor/ARB represents evidence-based triple therapy with complementary mechanisms. 1, 2
• If blood pressure remains uncontrolled on optimized triple therapy, add spironolactone 25-50 mg daily as the preferred fourth-line agent for resistant hypertension. 2

Critical Lifestyle Modifications

Lifestyle modifications are particularly important in Black patients and should be reinforced at every visit. 1

• Dietary sodium restriction to <2 g/day can reduce systolic blood pressure by 5-10 mmHg and is especially effective in Black patients. 1, 3
• Weight reduction, increased physical activity, and the DASH diet provide additive blood pressure reductions of 10-20 mmHg. 1, 2
• However, adoption of lifestyle recommendations is often challenging in ethnic minority patients due to poor social support, limited access to exercise opportunities and healthy foods, and financial considerations. 1

Important Caveats to Avoid

• Do not exclude any class of antihypertensive agent based solely on race when using combination therapy—racial differences should guide initial selection but not limit multidrug regimens. 1
• Verify medication adherence before escalating therapy, as non-adherence is the most common cause of apparent treatment resistance. 2
• Rule out secondary causes of hypertension (primary aldosteronism, renal artery stenosis, obstructive sleep apnea) if blood pressure remains severely elevated despite appropriate therapy. 2, 3