Generic blood pressure drugs are just as good as newer, more expensive ones, according to new data out of the study known as the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT).
When researchers followed up with ALLHAT participants taking one of three classes of blood pressure drugs for an average of 8.8 years, they found that a generic diuretic (chlorthalidone) was just as effective at lowering blood pressure and preventing heart attack and stroke as a name-brand calcium channel blocker (Norvascor) or ACE inhibitor (Prinivil, Zestril).
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The only significant differences actually favored the diuretic, reported Dr. Paul Whelton of Loyola University Medical Center in Maywood, Ill., and colleagues. Heart failure hospitalization and fatalities remained lower at 8.8 years with the diuretic compared with the calcium channel blocker. And fatal strokes remained lower compared with the ACE inhibitor.
Whelton presented the results at the China Heart Congress and International Heart Forum in Beijing. Generic diuretics cost $25 to $40 per year compared with up to $300 to $600 annually for newer brand-name hypertension drugs, according to a press release from Loyola.
The ALLHAT investigators have consistently pointed to cost as yet another advantage of diuretics. Joint National Committee (JNC7) guidelines give preference to diuretics as a first-line agent after lifestyle measures, although international guidelines have tended to disagree.
But the message may simply be that the specific drug or method used might not matter, as long as it controls blood pressure," explained Dr. Stephen L. Kopecky of the Mayo Clinic in Rochester, Minn.
"It can be lifestyle, it can be exercise, it can be weight loss, it can be not smoking and drinking," he said in an interview. "What we're finding over and over again is it really is important getting your numbers under control no matter how you do it."
The ALLHAT trial was designed to compare the three classes primarily on occurrence of a composite endpoint of fatal coronary heart disease or nonfatal heart attack. The trial's initial five-year double-blind phase included 33,357 high-risk hypertensive patients ages 55 years or older randomized to treatment with one of the three drugs between 1994 and 2002.
A fourth arm using an alpha-blocker (Cardura) stopped early because of elevated mortality, heart failure, and stroke risks, and was not included in Whelton and colleagues' analysis.
All treatments were given at doses designed to reach a blood pressure under 140/80 mm Hg.
After the randomized therapy period ended, participants were passively observed using administrative databases for four to five years, for a total follow-up experience of eight to 13 years from the time of randomization (an average of 8.8 years).
During this extended period, there was no difference in occurrence of cardiovascular disease mortality between patients originally assigned to either of the three drugs. However, no information on blood pressure or medication use was available for the extended follow-up period, the researchers noted.
"To follow somebody up eight years later when you really don't know what's happening in the interim -- what they've been taking -- is very, very difficult," Kopecky cautioned in the interview.
But the large size of the trial helped, he said. Moreover, it was reassuring that at least no ill effects appeared over the long term with these drugs, Kopecky added.
Since the ALLHAT study started, the calcium channel blocker and ACE inhibitor used have become available generically as well, commented Kopecky.