Millions of patients taking the drug Vytorin as a hedge against heart disease should consider switching to proven treatments following a failed trial — but not without checking with their physicians first, an American Heart Association doctor said Monday.
"Is there another way to lower your high cholesterol? What we don't want is patients stopping the drugs without talking to their doctors," said Dr. Robert O. Bonow, past president of the heart association and chief of cardiology at Northwestern University.
Bonow and other medical experts called for a return to the use of traditional cholesterol-lowering drugs, known as statins,long shown to be successful at preventing heart disease.
"The statins have been proven over and over again," he said.
Full results of a trial of Vytorin and one of its components, Zetia, stunned the cardiac community by showing that although the drugs lowered cholesterol as expected, they failed to reduce heart disease.
"It is a wrinkle we weren't anticipating," Bonow said.
Early news that the drugs didn't work as anticipated was first released in January, but the full results of the trial, known as Enhance, were presented Sunday at a meeting of the American College of Cardiology conference in Chicago and online in the New England Journal of Medicine.
Bonow cautioned that patients who are taking Vytorin or Zetia might have been prescribed those drugs for specific reasons. Some patients may have experienced side effects with statins, or been unable to tolerate the high doses of the drug required to lower cholesterol.
Some doctors attending the Chicago conference said they'd been reconsidering their use of Vytorin after being surprised by preliminary results this winter. Dr. Michael Ring, a cardiologist in Spokane, Wash., said initially it made sense to think that lowering LDL cholesterol would prevent heart disease.
"It was very easy to be lulled into that hypothesis," Ring said. "I swallowed it, hook, line and all."
Now, though, Ring said he'll be more likely to switch patients from Vytorin to Crestor, a statin, unless they are unable to tolerate statins.
Billions in sales
The study of Vytorin, manufactured by Merck & Co Inc., and Zetia, manufactured by Schering-Plough Corp., was closely watched because the drugs have been prescribed to millions of people and generated about $5 billion in sales despite limited proof of benefit. Vytorin costs about $3 a pill.
Vytorin, which came out in 2004, combines the generic statin Zocor with the lipid reducer Zetia. Zetia, which came out in 2002, works in a different way to attack cholesterol.
Both Vytorin and Zetia alone lowered LDL cholesterol — known as the "bad" cholesterol — which doctors have long believed was a good way to prevent heart disease. However, the study showed the drugs failed to reduce the plaque buildup responsible for heart disease in 720 high-risk patients.
Traditional statins such as Merck's Zocor, which is now available as a $1-a-pill generic, have been proven to lower cholesterol and curb heart disease.
Patients in the Enhance trial had cholesterol three times normal levels, which may have contributed to the results, Bonow noted.
"It's not totally surprising that their carotid arteries are not getting better," he said, adding that the patients probably benefitted by the previous use of statins.
The drug trial was not designed to test the safety of Vytorin, Bonow noted. So far, there appear to be no safety problems with the drug, but that remains uncertain, he said.
Final results of the Enhance trial are a worry for Orville Crook, 68, of Chesapeake, Va. The retired supermarket executive takes Vytorin now, but he was on Zocor and Zetia together for years. He raised the issue with his doctor after hearing first reports that Vytorin might not work.
"That's got me worried, that's got me concerned," said Crook, who had a heart attack in 1997 and an operation to clear a blocked artery.
He and his doctor adopted a wait-and-see attitude in January, but now that's likely to change.
"I called my cardiologist and he said 'Hold with Vytorin,'" Crook said. "Now that the study's out, he's talking with other people and we're going to decide what to do. I have an appointment April 11. I guess we'll find out a week from Friday."