Is chlorthalidone better than hydrochlorothiazide in reducing cardiovascular events in hypertensives?

PURPOSE OF REVIEW: Hydrochlorthiazide (HCTZ) is the tenth most commonly prescribed drug in recent data. Although no head-to-head trials compare HCTZ with the uncommonly prescribed chlorthalidone (CTDN) in reducing cardiovascular events (CVEs), numerous other data are available. RECENT FINDINGS: Head-to-head trials have shown CTDN's superiority in antihypertensive potency, particularly during the critical nighttime period (SBP difference 7.1 mmHg), due to the differences in duration of action (16-24 h for HCTZ versus 48-72 h for CTDN). In an observational cohort study, compared with HCTZ, CTDN was associated with lower left ventricular hypertrophy. In another observational cohort analysis (n = 12,866), the percentage risk reduction in CVEs from CTDN versus HCTZ was 21 [95% confidence interval (CI) 8-32], P = 0.002. In network meta-analyses of randomized trials (n = 50,946), CTDN was superior to HCTZ in reducing congestive heart failure and in reducing all CVEs: percentage risk reduction 21 (95% CI 12-28), P < 0.0001. A statistically significant reduction in CVEs by CTDN versus HCTZ persisted even when reduction in office SBP produced by the two diuretics was identical, further strengthening the case for CTDN. SUMMARY: Direct and indirect evidence demonstrates that CTDN is superior to HCTZ in reducing CVEs and is congruent with the recent changes in the guidelines for hypertension management.