Thiazide Diuretics: Selection and Monitoring

Thiazide and thiazide-like diuretics remain first-line antihypertensive agents per all major guidelines (ACC/AHA, JNC-8, ESC/ESH). Clinical evidence distinguishes between agents: chlorthalidone has the strongest cardiovascular outcome evidence (ALLHAT trial — 33,357 patients; demonstrated equivalent or superior cardiovascular outcomes compared to amlodipine and lisinopril in high-risk hypertensive patients). Chlorthalidone's pharmacokinetic advantages include a longer half-life (40-60 hours vs. HCTZ 6-12 hours), providing more consistent 24-hour blood pressure control including nocturnal blood pressure reduction, and 1.5-2× greater potency than HCTZ (12.5 mg chlorthalidone ≈ 25 mg HCTZ). Indapamide is a thiazide-like diuretic with unique properties: it has direct vasodilatory effects independent of diuresis, is more metabolically neutral than HCTZ or chlorthalidone (less hyperglycemia, less hypokalemia), retains some efficacy at lower GFR, and has strong outcome evidence (HYVET trial demonstrated benefit in hypertension treatment in patients >80 years; PROGRESS trial showed stroke reduction). The prescribing NP must consider: (1) Agent selection — chlorthalidone preferred for most; indapamide for metabolic concerns or elderly; HCTZ acceptable but less evidence; (2) Dose optimization — most BP benefit at low doses (12.5-25 mg chlorthalidone) with diminishing returns...