A 54-year-old man with newly diagnosed stage 1 hypertension (average BP 142/90) has no comorbidities, normal kidney function, and a family history of stroke. He is ready to start a single first-line antihypertensive. According to current AHA/ACC preferred thiazide selection, which agent has the strongest outcome-trial evidence and is preferred over hydrochlorothiazide?

Question

Accepted Answer

✅ D. Chlorthalidone (Thalitone)
Chlorthalidone is the AHA/ACC-preferred thiazide-type diuretic for hypertension because of its longer duration of action (40–60 hours versus 6–12 for HCTZ) and robust outcome data from major trials including ALLHAT and SHEP, which demonstrated reductions in cardiovascular events and stroke. Dosing typically starts at 12.5–25 mg once daily. It tends to cause slightly more hypokalemia than HCTZ, so monitor electrolytes.

❌ A. Hydrochlorothiazide (Microzide)
HCTZ is the most commonly prescribed thiazide in the US, but it has a shorter half-life and weaker outcome-trial data compared with chlorthalidone. It is still acceptable, especially in fixed-dose combinations, but guidelines favor chlorthalidone when a thiazide is chosen as true first-line therapy.

❌ B. Triamterene/hydrochlorothiazide (Dyazide)
This combination is useful when a patient develops hypokalemia on HCTZ alone, but it is not first-line monotherapy. Triamterene adds potassium-sparing activity, not additional BP benefit or outcome data.

❌ C. Indapamide (Lozol)
Indapamide is a thiazide-like diuretic with good evidence (HYVET trial in the very elderly) and is commonly used internationally, but in the US AHA/ACC framework chlorthalidone is the preferred first-line thiazide-type agent.

:::pearl
Preferred thiazide per AHA/ACC: chlorthalidone. Longer half-life and stronger CV outcome data than HCTZ.
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Chlorthalidone

✅ Indications

⚙️ Mechanism of Action

📏 Dosing

🚫 Contraindications

⚠️ Adverse Effects

🔬 Monitoring

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