Sept. 2 (HealthDay News) -- Despite their popularity, so-called "combination therapies" may not be the most effective treatment for high cholesterol, Canadian researchers report.

In their review, the scientists analyzed data from 102 studies that tested combination therapies involving ezetimibe, niacin, bile acid sequestrants and omega-3 fatty acids. They concluded that there is little evidence to support the widespread use of combination therapies to lower cholesterol.

The results of this comprehensive review of clinical studies are important, as lowering cholesterol has been shown to decrease the risk of heart attack and stroke, and more than 35 million Canadians and Americans are prescribed cholesterol-lowering drugs each year, according to a news release from the Ottawa Hospital Research Institute.

In the new study, stroke specialist Dr. Mukul Sharma and colleagues from the Ottawa Hospital Research Institute and the University of Ottawa looked for evidence that supported the use of combination therapies vs. high-dose statin therapy.

Although statins are the most commonly used class of cholesterol-lowering drugs, some people don't respond to the standard dose. For these people, statins are increasingly being prescribed at higher doses or in combination with other types of drugs, according to the report published online Sept. 1 in the Annals of Internal Medicine.

"Our review shows that so far, there is not enough evidence to support the widespread use of combination therapies over high-dose statin therapy," Sharma said in the news release. "For most patients who don't respond to a low dose of statin, it would make sense to try a higher dose of statin before trying a combination therapy. If the high-dose statin does not work or is not well-tolerated, or if there are other special circumstances, a combination therapy may be a good option, but until more research is done, this is not recommended for most patients."

SOURCE: Ottawa Hospital Research Institute, news release, Aug. 31, 2009