WASHINGTON - U.S. health officials are adding new safety warnings about risks of memory loss and elevated blood sugar to statins, a widely prescribed group of cholesterol-lowering medications.
The Food and Drug Administration said Tuesday it is making labelling changes to medicines like Pfizer's Lipitor, AstraZeneca's Crestor and Merck & Co. Inc.'s Zocor. The drugs are used by tens of millions of Americans to help prevent heart-related problems associated with cholesterol.
New labelling on all such drugs will warn of memory loss and confusion reported among certain patients taking statins. The problems were not generally serious and went away after patients stopped taking the drugs, according to the FDA.
The updated labels will also mention elevated levels of blood sugar, associated with diabetes, that have been reported in some patients taking statins.
A growing number of studies published over the last five years have found a link between statin use and Type 2 diabetes. Last June, a report in the Journal of the American Medical Association analyzed five older randomized trials and concluded the increased risk was small but real for people taking higher doses of any statin.
Statins are mainly prescribed to prevent heart attacks in people with clogged arteries and work by dramatically lowering LDL, or bad cholesterol. They were the third bestselling drug class in the U.S. for 2010 with sales of $18.8 billion.
A Health Canada spokeswoman said the current Canadian labels for some statin drugs already contain information about the risk of memory loss and advise diabetics to inform their doctors if blood sugar level changes are noticed.
Leslie Meerburg said Health Canada is evaluating the available information and will work with manufacturers to update labels if additional warnings are needed.
In addition to the new label warnings, the FDA said it will remove a long-standing caution related to liver injury. The drugs' labels previously recommended routine testing of liver enzymes to avoid injury. The agency now recommends a single test when patients first begin taking statins.
"FDA has concluded that serious liver injury with statins is rare and unpredictable in individual patients, and that routine periodic monitoring of liver enzymes does not appear to be effective in detecting or preventing this rare side effect," the agency said in a statement.
In addition to statins, the new labelling changes apply to several combination drugs that mix older statins with newer cholesterol medicines, including Merck's Vytorin and Abbott Laboratories Simcor.
- With files from The Canadian Press