To the Editor: Dr Psaty and colleagues1 compared the results of 2 meta-analyses, each of which looked individually at the efficacy of either chlorthalidone or other low-dose diuretics compared with placebo, not with each other. Based on small efficacy differences, Psaty et al concluded that “major health outcomes for chlorthalidone and other thiazide-like drugs appear to be similar.” We believe that it is necessary to directly compare treatments to reach conclusions about differences between them.
Evidence from active control clinical trials distinguishes chlorthalidone from diuretics that are similar but hardly identical.2 After an interim analysis at 5 years of follow-up in the Multiple Risk Factor Intervention Trial (MRFIT), the steering committee recommended that only chlorthalidone (and not hydrochlorothiazide) be used in the intervention arm.3 In the 9 clinics whose staff initially prescribed predominantly hydrochlorothiazide, coronary heart disease (CHD) mortality and all-cause mortality were increased by 44% and 16%, respectively, compared with usual care. In the 6 clinics whose staff predominantly used chlorthalidone, CHD mortality and all-cause mortality were decreased by 58% and 41%, respectively, compared with usual care. After changing diuretics, the CHD and all-cause mortality in clinics whose staff had initially predominantly used hydrochlorothiazide decreased by 28% and 26%, respectively, compared with usual care, over the ensuing 5 years. The longer-term success of treatment in MRFIT’s special intervention arm may be attributable in part to chlorthalidone, as men randomized to care in the community predominantly received hydrochlorothiazide.3
Contrasting results from 2 simultaneously-performed randomized clinical trials in North America and Australia also support the benefits of chlorthalidone. In the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT), chlorthalidone was superior to lisinopril in reducing blood pressure and in preventing stroke, combined cardiovascular events, and heart failure.4 In the Second Australian National Blood Pressure Trial, enalapril was found to be superior to hydrochlorothiazide in preventing major cardiovascular events or death in men, despite roughly equal reductions in blood pressure.5 Chlorthalidone is 50% to 100% more potent than hydrochlorothiazide on an equal-dosage basis, and has a much longer serum elimination half-life.2 We believe the evidence from active control clinical trials supports its use over other thiazide-type diuretics.
Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature
Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal
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