What is the recommended next step for a patient with hypertension who is currently on 5 mg of amlodipine (calcium channel blocker) and remains hypertensive?

Management of Hypertension in a Patient Inadequately Controlled on Amlodipine 5 mg

For a patient who remains hypertensive on amlodipine 5 mg daily, the recommended next step is to increase the dose to amlodipine 10 mg once daily. 1

Rationale for Dose Escalation

The FDA-approved dosing for amlodipine indicates that while the usual initial antihypertensive dose is 5 mg once daily, the maximum dose is 10 mg once daily 1. When blood pressure remains uncontrolled on the initial dose, titration to the maximum dose is appropriate.

Evidence Supporting Dose Escalation

A Phase III double-blind study specifically examined patients who had insufficient response to amlodipine 5 mg and found that increasing to 10 mg resulted in:

• Significantly greater reduction in systolic blood pressure (-13.7 mmHg vs -7.0 mmHg, p<0.001)
• Significantly greater reduction in diastolic blood pressure (-6.8 mmHg vs -2.7 mmHg, p<0.001)
• Higher responder rates (44.0% vs 28.5%, p=0.002) 2

Timing of Dose Adjustment

When titrating amlodipine:

• Wait 7-14 days between titration steps 1
• Some evidence suggests waiting up to 6 weeks before dose escalation, as blood pressure may continue to decrease steadily until the end of the sixth week of treatment 3

Alternative Approaches if Dose Escalation is Ineffective

If increasing to amlodipine 10 mg does not achieve target blood pressure, the 2020 International Society of Hypertension guidelines recommend the following steps 4:

For Non-Black Patients:

1. Add a thiazide/thiazide-like diuretic
2. If still uncontrolled, add spironolactone or, if not tolerated, consider amiloride, doxazosin, eplerenone, clonidine, or a beta-blocker

For Black Patients:

1. Add a diuretic if not already on one, or add an ACE inhibitor/ARB
2. If still uncontrolled, add spironolactone or other agents as above

Combination Therapy Considerations

If amlodipine 10 mg monotherapy is insufficient, combination therapy should be considered:

• The combination of amlodipine with an ARB (such as losartan) has been shown to be effective in patients who respond poorly to amlodipine 5 mg 5
• Similarly, the combination of amlodipine with an ACE inhibitor (such as benazepril) has demonstrated efficacy in patients not adequately controlled on ACE inhibitor monotherapy 6

Blood Pressure Targets

Treatment should aim to achieve:

• BP <130/80 mmHg for most patients
• For elderly patients (65-79 years): 130-139/80 mmHg
• For very elderly patients (≥80 years): 140-150/<80 mmHg 7

Monitoring Recommendations

• Reassess blood pressure within 3 months after dose adjustment 4
• Monitor for potential side effects, particularly peripheral edema, which may occur at the higher 10 mg dose (reported incidence of 4%) 2

Important Considerations

• Ensure proper blood pressure measurement technique using validated devices and appropriate cuff size
• Verify medication adherence before concluding that the current dose is ineffective
• Consider home blood pressure monitoring to better assess treatment efficacy

Remember that while increasing the dose is the recommended first step, the ultimate goal is to reduce morbidity and mortality through effective blood pressure control, which may eventually require combination therapy in many patients.