The diuretic chlorthalidone -- an older, cheaper drug for high blood pressure -- may be the best for lowering night-time blood pressure and preventing heart failure, at least in the short term, studies suggests.
What’s the Best Diuretic for High Blood Pressure? When it comes to the diuretic drugs used to treat high blood pressure, the original may still be the best, researchers report in the journal Hypertension (Volume 47, page 352). In a study of 30 adults with high blood pressure, researchers found that a diuretic called chlorthalidone bested a newer, more widely used diuretic called hydrochlorothiazide (HCTZ). Specifically, the diuretic chlorthalidone was more effective at keeping nighttime blood pressure down, likely because it is more long acting than HCTZ.
The diuretic chlorthalidone became available in 1957 and was the first of the modern diuretics used to treat hypertension. In the past 20 years, the diuretic has fallen out of favor, in part because it can cause blood potassium levels to fall -- but also because many doctors assume chlorthalidone and HCTZ are equally effective.
But in the study, 24-hour systolic blood pressure fell to a greater degree when participants took the diuretic chlorthalidone for eight weeks than when they took HCTZ (12 vs. 7 mm Hg). Chlorthalidone was more effective primarily because of its effects on overnight blood pressure. Whether the difference translates into fewer heart attacks and strokes is unknown. And even if the diuretic chlorthalidone is the better drug, HCTZ is more widely available and used in many more combination blood pressure products.
More on chlorthalidone ...
A study, of more than 33,000 older adults with hypertension, found that those given the diuretic chlorthalidone were about half as likely to develop heart failure in their first year of treatment as those who took a calcium channel blocker or an ACE inhibitor.
In general, diuretics are recommended as the first drug of choice for hypertension -- with ACE inhibitors, calcium channel blockers, or other medications added if necessary. The new findings are based on data from a study, which pitted the diuretic chlorthalidone against the calcium channel blocker amlodipine (Norvasc) and the ACE inhibitor lisinopril (Prinivil, Zestril). Researchers wanted to know whether the three drugs had different effects on the risk of heart failure, a common complication of hypertension.
Overall, people given the diuretic were less likely to develop heart failure in the first year. After that, ACE inhibitor patients fared just as well. Those on the calcium channel blocker, however, still had a somewhat higher heart failure risk. Nonetheless, heart failure is only one potential consequence of hypertension, and medication choices have to be individualized. Many people need more than one drug to control their blood pressure. This study was reported in the journal Circulation (Volume 113, page 2201).
