Research finds little evidence to support combination therapies to lower cholesterol

August 31, 2009

In the most comprehensive review of clinical studies to date, experts from the Ottawa Hospital Research Institute and the University of Ottawa have concluded that there is little evidence to support the widespread use of so-called “combination therapies” to lower cholesterol. The results are published in the September 1, 2009 online edition of Annals of Internal Medicine.

Statins are the most widely prescribed class of cholesterol lowering drugs, but they are increasingly being used at a higher dose, or in combination with other types of drugs, for people do don’t respond to the standard dose of statin.

With funding from the Agency for Healthcare Research and Quality in the US, Ottawa stroke specialist Dr. Mukul Sharma and colleagues conducted a systematic review to determine how much evidence supports the use of these combination therapies versus high dose statin therapy. They examined 102 studies that tested combination therapies involving ezetimibe, niacin, bile acid sequestrants and omega-3 fatty acids.

“Our review shows that so far, there is not enough evidence to support the widespread use of combination therapies over high dose statin therapy,” said Dr. Sharma. “Thus, 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.”

Dr. Sharma also noted that it is particularly important to have this kind of independent analysis of drugs which are heavily marketed. Dr. Sharma is the Medical Director of the Regional Stroke Centre at The Ottawa Hospital, a Clinical Investigator at the Ottawa Hospital Research Institute, Assistant Professor of Medicine at the University of Ottawa and Deputy Director of the Canadian Stroke Network.

It is estimated that more than 35 million Canadians and Americans are prescribed cholesterol lowering drugs every year. Lowering cholesterol has been shown to decrease the risk of heart attack, stroke and other cardiovascular conditions.

About the Ottawa Hospital Research Institute
The Ottawa Hospital Research Institute (OHRI) is the research arm of The Ottawa Hospital and is an affiliated institute of the University of Ottawa, closely associated with the University’s Faculties of Medicine and Health Sciences. The OHRI includes more than 1,300 scientists, clinical investigators, graduate students, postdoctoral fellows and staff conducting research to improve the understanding, prevention, diagnosis and treatment of human disease.

Media Contacts
Jennifer Paterson
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Ottawa Hospital Research Institute
613-798-5555 ext. 73325

Hazel Harding
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The Ottawa Hospital