Cheap diuretics are the best first step in treating high blood pressure to prevent heart failure, U.S. researchers reported on Monday.

Their study, published in the American Heart Association journal Circulation, supports a 2002 U.S. government report recommending that patients with high blood pressure should start taking a diuretic first, and only add drugs such as ACE inhibitors or beta-blockers if their blood pressure needs to be lowered further.

Diuretics lower blood pressure by ridding the body of excess water, often making patients urinate more often. In 1982, diuretics were prescribed in 56 percent of the cases of high blood pressure treated by drugs, but by 1992 they were prescribed in only 27 percent of the cases.

Their use has been creeping back up since the 2002 report by the U.S. National Heart, Lung and Blood Institute.

“This study provides evidence for the superiority of diuretics over calcium channel blockers and ACE inhibitors as the base of an antihypertensive regimen to prevent heart failure,” said Dr. Barry Davis of the University of Texas School of Public Health in Houston, who led the study.

High blood pressure forces the heart to pump harder to keep blood circulating. Over time, this added workload can cause heart failure, in which the heart becomes enlarged but weaker and blood is not adequately pumped through the heart.

Heart failure patients become increasingly tired and short of breath and lose kidney function. Half die within 5 years of diagnosis.

“Over 90 percent of people who develop heart failure first had high blood pressure,” said Davis.

“Diuretics are better than calcium channel blockers at preventing heart failure, and better, at least in the short term, than ACE inhibitors,” Davis said in a statement.

“One reason diuretics may have an advantage over other drugs is that they are good at decreasing the volume that the heart has to deal with, and the other drugs don’t do that. ACE inhibitors remodel the heart, which may have a more long-term effect on preventing heart failure.”

His team analyzed data from the giant Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial, or ALLHAT, in which several drug companies donated their name-brand products for use.

The cheaper, generic, diuretics did the best job of lowering cholesterol and preventing heart failure.

During the first year of the study, patients given a calcium-channel blocker or ACE inhibitor were 40 percent more likely to be hospitalized or die from heart failure as patients taking a diuretic.