What are the considerations for using thiazides (diuretics) in African Americans with hypertension?

From the Guidelines

Thiazide diuretics are recommended as first-line therapy for African Americans with hypertension due to their superior efficacy in this population. Medications such as hydrochlorothiazide (12.5-50 mg daily), chlorthalidone (12.5-25 mg daily), or indapamide (1.25-2.5 mg daily) are commonly prescribed options 1. African Americans typically have lower renin levels and are more salt-sensitive, making them particularly responsive to the sodium-excreting effects of thiazides. When prescribing thiazides, clinicians should monitor for potential side effects including hypokalemia, hyperglycemia, hyperuricemia, and hyperlipidemia. Regular laboratory monitoring of electrolytes, glucose, and uric acid levels is recommended, especially during the initial weeks of therapy. Potassium supplementation may be necessary if levels drop below normal range. For patients with comorbid diabetes or metabolic syndrome, lower doses are preferable to minimize metabolic effects, and combination with ACE inhibitors or ARBs may be beneficial. Thiazides are often more effective when combined with calcium channel blockers in African American patients with resistant hypertension, creating synergistic antihypertensive effects while potentially reducing side effects through lower dosing of each medication.

Some key considerations for using thiazides in African Americans with hypertension include:

• Monitoring for potential side effects and adjusting doses as needed
• Combining thiazides with other antihypertensive agents, such as calcium channel blockers, to achieve optimal blood pressure control
• Considering the use of thiazides in patients with comorbid conditions, such as diabetes or metabolic syndrome
• Being aware of the potential for increased risk of certain side effects, such as hypokalemia, in African American patients

Overall, the use of thiazide diuretics as first-line therapy for African Americans with hypertension is supported by the evidence, and clinicians should consider these medications as a primary treatment option for this population 1.

From the FDA Drug Label

PRECAUTIONS ... Information for Patients: ... No specific information is provided regarding the use of thiazides in African Americans.

The FDA drug label does not answer the question.

From the Research

Considerations for Using Thiazides in African Americans with Hypertension

• The use of thiazides, such as hydrochlorothiazide (HCTZ) and chlorthalidone, in African Americans with hypertension requires careful consideration of their efficacy and safety profiles 2, 3.
• Studies have shown that chlorthalidone may be more effective than HCTZ in lowering blood pressure in African Americans, with a greater reduction in systolic and diastolic blood pressure observed in one study 2.
• However, the same study found that HCTZ treatment led to significantly lower rates of hypokalemia and hyperuricemia in African Americans, compared to chlorthalidone 2.
• The Eighth Joint National Committee (JNC-8) guidelines recommend different treatment approaches for African American and non-African American patients with hypertension, with thiazide diuretics being one of the recommended options for African American patients 4.
• Other studies have suggested that ACE inhibitors and ARBs may not be as effective in African American patients with hypertension, and that combination therapy with a calcium channel blocker or thiazide diuretic may be more efficacious 5.
• The choice of thiazide diuretic, either HCTZ or chlorthalidone, should be based on individual patient characteristics and medical history, as well as the potential risks and benefits of each medication 2, 3, 6.

Efficacy and Safety of Thiazides in African Americans

• The efficacy of thiazides in lowering blood pressure in African Americans has been demonstrated in several studies, with chlorthalidone showing greater blood pressure lowering effects than HCTZ in some studies 2, 3.
• However, the safety profile of thiazides in African Americans must also be considered, with hypokalemia and hyperuricemia being potential risks associated with these medications 2, 3.
• The use of HCTZ has been associated with increased cardiovascular death and coronary artery disease in some studies, although the evidence is not conclusive 6.

Clinical Implications

• Clinicians should carefully consider the efficacy and safety profiles of thiazides when selecting a treatment option for African American patients with hypertension 2, 3, 4, 5, 6.
• Combination therapy with a calcium channel blocker or thiazide diuretic may be a viable option for African American patients with hypertension, particularly if ACE inhibitors or ARBs are not effective or are contraindicated 5.
• Further research is needed to fully understand the efficacy and safety of thiazides in African American patients with hypertension, and to inform evidence-based treatment guidelines 2, 3, 4, 5, 6.