Is a second antihypertensive agent recommended for an African American patient with a Mean Arterial Pressure (MAP) of 104 on amlodipine (Norvasc) 5 mg and which one is best?

From the Guidelines

Yes, a second antihypertensive agent is recommended for this African American patient with a MAP of 104 on amlodipine 5 mg, as this indicates inadequate blood pressure control. The best choice would be a thiazide diuretic such as hydrochlorothiazide (HCTZ) 12.5-25 mg daily or chlorthalidone 12.5-25 mg daily, as supported by the 2017 ACC/AHA guideline 1. These agents work synergistically with calcium channel blockers like amlodipine by addressing different mechanisms of hypertension. Thiazide diuretics are particularly effective in African American patients due to their tendency toward salt sensitivity and low-renin hypertension, as noted in the 2017 ACC/AHA guideline 1 and the 2018 Journal of the American College of Cardiology article 1. The combination of amlodipine with a thiazide diuretic provides complementary actions - amlodipine relaxes blood vessels while the diuretic reduces fluid volume. When initiating the thiazide, start at the lower dose (12.5 mg) and monitor electrolytes, particularly potassium and sodium, within 1-2 weeks, as suggested by the 2018 Journal of the American College of Cardiology article 1. Blood pressure should be reassessed after 2-4 weeks to determine if the combination therapy is effective or if further dose adjustments are needed. If the patient develops hypokalemia, consider adding a potassium supplement or switching to chlorthalidone, which has a longer duration of action and may provide better 24-hour blood pressure control, as recommended in the 2019 American Journal of Kidney Diseases article 1. Key points to consider include:

• Thiazide diuretics are effective in lowering blood pressure in African American patients 1
• The combination of amlodipine with a thiazide diuretic provides complementary actions 1
• Monitoring electrolytes and blood pressure is crucial when initiating combination therapy 1
• Chlorthalidone may be a better option if the patient develops hypokalemia 1

From the FDA Drug Label

Many patients will require more than one drug to achieve blood pressure goals. Some antihypertensive drugs have smaller blood pressure effects (as monotherapy) in black patients, and many antihypertensive drugs have additional approved indications and effects (e.g., on angina, heart failure, or diabetic kidney disease).

A second antihypertensive agent is recommended for an African American patient with a Mean Arterial Pressure (MAP) of 104 on amlodipine (Norvasc) 5 mg, as many patients require more than one drug to achieve blood pressure goals. Lisinopril may not be the best option as it was less effective in reducing blood pressure in Blacks than in Caucasians 2. Losartan may also not be the best option as there is evidence that the benefit of losartan in reducing the risk of stroke in patients with hypertension and left ventricular hypertrophy does not apply to Black patients 3. The best second agent for this patient is not explicitly stated in the provided drug labels.

From the Research

Recommendation for Second Antihypertensive Agent

For an African American patient with a Mean Arterial Pressure (MAP) of 104 on amlodipine (Norvasc) 5 mg, the decision to add a second antihypertensive agent depends on various factors, including the patient's blood pressure goals and overall health status.

• The study 4 suggests that African American patients with systolic BP ≥15 mm Hg above target level or a diastolic BP ≥10 mm Hg above target should be considered for first-line combination therapy.
• Another study 5 indicates that the use of ACE inhibitors or ARBs as monotherapy in black patients may have reduced efficacy, but combination therapy with a calcium channel blocker or thiazide diuretic is efficacious.

Choice of Second Agent

The choice of a second antihypertensive agent for an African American patient on amlodipine 5 mg should be based on the patient's individual needs and medical history.

• A study 6 found that amlodipine and valsartan produced similar reductions in blood pressure in African American patients with uncomplicated hypertension.
• The study 7 compared the efficacy and safety of losartan/hydrochlorothiazide and candesartan/amlodipine combinations and found that both combinations were effective in reducing blood pressure, but losartan/hydrochlorothiazide had fewer adverse effects on metabolic parameters.
• The study 4 suggests that diuretics, such as chlorthalidone, may be a good choice for African American patients, as they have been shown to be effective in reducing blood pressure and preventing cardiovascular events in this population.
• The study 8 found that thiazide diuretics were commonly used as monotherapy in African American patients, and that combination therapy with a calcium channel blocker or ACE inhibitor/ARB may be effective in achieving blood pressure control.

Considerations for African American Patients

When selecting a second antihypertensive agent for an African American patient, it is essential to consider the patient's individual characteristics, such as kidney function, diabetes status, and cardiovascular risk factors.

• The study 5 highlights the importance of considering the potential reduced efficacy of ACE inhibitors or ARBs in African American patients and the need for combination therapy to achieve optimal blood pressure control.
• The study 4 emphasizes the importance of tailoring treatment to the individual patient's needs, rather than relying solely on race-based guidelines.