LEXINGTON, Ky. -- Kentucky horse racing regulators approved a ban Wednesday on the race-day use of an anti-bleeding drug, making it the first state in the nation to take such action.

The proposed regulation would phase in the race-day ban on furosemide in graded or listed stakes races, beginning with 2-year-old horses in 2014. The ban would apply to the Kentucky Derby in 2015.

The Kentucky Horse Racing Commission approved the proposal 7-5. The measure still needs the approval from state lawmakers.

"I think this is the right thing to do at the correct time," commissioner Tracy Farmer said. "We cannot succeed as a sport with drugs."

The drug is banned across much of the world because it is considered a performance enhancer.

Furosemide is marketed as Lasix and Salix and is the only medication allowed to be given to horses on race day in the U.S. The drug is used commonly to treat pulmonary hemorrhaging in racehorses.

Supporters said the ban would improve the sport's image. Opponents say any ban will spur owners and trainers to move horses to states that don't ban the drug.

Commissioner Thomas Conway said the measure would create another competitive disadvantage for Kentucky racing.

"This is a very risky thing that we are doing," he said.

The debate comes as Kentucky racetracks have been struggling to keep pace with competitors in other states where purse money is augmented by slot machines and other gambling. Kentucky lawmakers have steadfastly refused to allow slot machines at the state's race tracks.

Commission chairman Robert Beck Jr. said horse racing suffers from an image problem. He said the proposed regulation was aimed at winning over potential race fans "who don't want anything to do with the industry because they think it's ... drug-infested."

Beck said he anticipates other prominent racing states to follow Kentucky's lead.

"If that does not happen, we'll continue to monitor the situation as we go along, and at an appropriate time we would take a look at it," he added.

The commission's action won a quick endorsement from Gov. Steve Beshear.

"We must instill a sense of confidence in the betting public's mind that horses running in graded and listed stakes on Kentucky tracks are doing so on their own abilities," Beshear said in a statement.

A more sweeping ban -- aimed at completely phasing out use of furosemide on race days -- came before the Kentucky Horse Racing Commission in April, but that measure failed on a 7-7 vote.

The measure approved by the commission would take effect Jan. 1, 2014. It would prohibit use of furosemide less than 24 hours before post time for 2-year-olds competing in graded or listed stakes races.

The race-day prohibition would apply to 2- and 3-year-old horses competing in those races in 2015. The Kentucky Derby, run at Churchill Downs in Louisville, is for 3-year-old horses.

In 2016, the ban would apply to any horse entered to race in graded or listed stakes races in Kentucky.

Graded or listed stakes races amount to a fraction of all races in Kentucky. But those races command the biggest prize money and attract the upper-echelon horses. The proposed regulation would apply to thoroughbreds and quarterhorses.

Violations of the race-day drug ban would result in disqualification and forfeiture of purse money. Trainers or veterinarians would face license suspensions and fines.

Critics said the proposed ban would accelerate the decline in Kentucky racing. Commission member Frank Jones Jr. warned it would spur the loss of more horses to other states. The result, he said, will be fewer racing days in Kentucky, smaller fields and reduced wagering.

Longtime Kentucky trainer Dale L. Romans warned at a commission meeting this spring that imposing the race-day ban on Lasix would drive "the final nail in Kentucky racing" and said it would be "the most drastic change to American racing ever."

Last year, a bipartisan pair of lawmakers sought a national ban on performance-enhancing drugs in a bill that came three years after the death of Eight Belles at the 2008 Kentucky Derby. A drug test proved the horse was clear of steroids, but the death helped shine a light on safety problems and the lack of a single governing body for the sport.

Rick Dutrow, trainer of the 2008 Derby winner Big Brown, acknowledged he regularly injected the horse with the then-legal steroid stanozolol.

A 2009 study by three universities found that horses treated with furosemide had less hemorrhaging in their airways and lungs during exercise. The study was conducted by Colorado State University, the University of Melbourne in Australia and the University of Pretoria in South Africa.

In 1987, jockey Pat Day pulled 2-1 Derby favorite Demons Begone after a half-mile when the colt got a nosebleed.