What should be done for an adult patient with hypertension who continues to have elevated blood pressure readings despite taking amlodipine 5mg daily?

Management of Uncontrolled Hypertension on Amlodipine 5mg

For a patient with blood pressure 140/92 mmHg on amlodipine 5mg daily, you should first increase amlodipine to 10mg daily and reassess within 2-4 weeks before adding a second agent. 1, 2, 3

Immediate Action: Optimize Current Medication

• Increase amlodipine from 5mg to 10mg once daily, as the FDA-approved maximum dose is 10mg and most patients require this higher dose for adequate blood pressure control 3, 4
• The blood pressure of 140/92 mmHg represents stage 1 hypertension requiring treatment intensification, with the systolic reading at the threshold and diastolic elevated above target 1, 2
• Wait 7-14 days between dose titration to assess response, though you can titrate more rapidly if clinically warranted with frequent patient assessment 3
• Reassess blood pressure within 2-4 weeks after increasing the dose, with the goal of achieving target blood pressure within 3 months 1, 2

Target Blood Pressure

• Aim for <130/80 mmHg for most patients, or at minimum <140/90 mmHg 1, 2, 5
• For higher-risk patients with diabetes, chronic kidney disease, or established cardiovascular disease, target <130/80 mmHg 1
• Home blood pressure monitoring should target <135/85 mmHg, which corresponds to clinic blood pressure <140/90 mmHg 1, 5

If Blood Pressure Remains Uncontrolled on Amlodipine 10mg

Add an ACE inhibitor or ARB as the second agent to achieve guideline-recommended dual therapy 1, 2, 5

• The combination of amlodipine with an ACE inhibitor or ARB provides complementary mechanisms—vasodilation through calcium channel blockade and renin-angiotensin system inhibition 1
• This combination has demonstrated superior blood pressure control compared to either agent alone 1
• Adding an ACE inhibitor or ARB may also attenuate peripheral edema, which is more common with amlodipine monotherapy 1

Alternative: Add a thiazide-like diuretic (chlorthalidone 12.5-25mg or hydrochlorothiazide 25mg daily) 1, 2

• This combination is particularly effective for Black patients, elderly patients, or those with volume-dependent hypertension 1
• Chlorthalidone is preferred over hydrochlorothiazide due to its longer duration of action and superior cardiovascular outcomes 1

Race-Specific Considerations

• For Black patients, the combination of amlodipine plus a thiazide diuretic may be more effective than amlodipine plus an ACE inhibitor/ARB 1, 2
• For non-Black patients, either combination (amlodipine + ACE inhibitor/ARB or amlodipine + thiazide) is appropriate 1

If Triple Therapy Becomes Necessary

Add the third drug class to complete the evidence-based triple therapy regimen: ACE inhibitor/ARB + amlodipine + thiazide diuretic 1, 2, 5

• This combination targets three complementary mechanisms: renin-angiotensin system blockade, vasodilation, and volume reduction 1
• If blood pressure remains ≥160/100 mmHg despite three drugs at optimal doses, consider referral to a hypertension specialist 6, 1

Critical Steps Before Adding Medications

• Confirm medication adherence first, as non-adherence is the most common cause of apparent treatment resistance 1, 2
• Verify home blood pressure readings using a validated automated device with proper technique, averaging ≥2 readings on ≥2 occasions 1
• Screen for interfering substances: NSAIDs, decongestants, oral contraceptives, systemic corticosteroids, and herbal supplements (ephedra, St. John's wort) can all elevate blood pressure 1, 5
• Rule out secondary hypertension if blood pressure remains severely elevated, looking for primary aldosteronism, renal artery stenosis, obstructive sleep apnea, or pheochromocytoma 1, 2, 5

Essential Lifestyle Modifications

• Sodium restriction to <2g/day provides 5-10 mmHg systolic reduction 1, 5
• Weight loss if overweight/obese: 10 kg weight loss associated with 6.0 mmHg systolic and 4.6 mmHg diastolic reduction 1
• Regular aerobic exercise: minimum 30 minutes most days produces 4 mmHg systolic and 3 mmHg diastolic reduction 1, 5
• DASH diet reduces systolic and diastolic blood pressure by 11.4 and 5.5 mmHg more than control diet 1
• Alcohol limitation to <100g/week (approximately 7 standard drinks) 1, 5

Monitoring After Dose Increase

• Check blood pressure within 2-4 weeks after increasing amlodipine to 10mg 1, 2, 3
• Monitor for peripheral edema, the most common side effect of amlodipine, which occurs more frequently at higher doses 1, 4
• If adding an ACE inhibitor/ARB, check serum potassium and creatinine 2-4 weeks after initiation to detect hyperkalemia or acute kidney injury 1
• If adding a thiazide diuretic, check serum potassium and creatinine 2-4 weeks after initiation to detect hypokalemia 1

Common Pitfalls to Avoid

• Do not add a second agent before optimizing amlodipine to 10mg daily—this violates guideline-recommended stepwise approaches 1, 2
• Do not add a beta-blocker as the second or third agent unless there are compelling indications (angina, post-MI, heart failure with reduced ejection fraction, or heart rate control) 1, 5
• Do not combine an ACE inhibitor with an ARB—dual RAS blockade increases adverse events (hyperkalemia, acute kidney injury) without additional cardiovascular benefit 1, 2
• Do not delay treatment intensification—the patient has uncontrolled hypertension requiring prompt action to reduce cardiovascular risk 1, 2