Cholesterol-lowering statins such as Pfizer Inc.’s best-selling Lipitor will carry a warning about an increase in blood-sugar levels in patients, leading to a greater risk of diabetes, U.S. regulators said.
At the same time, the Food and Drug Administration today removed the need to monitor patients’ livers, saying serious liver injury is “rare” with statins including AstraZeneca Plc’s Crestor and Merck & Co.’s Zocor. The drugs also are tied to memory loss and confusion that is reversed when they are stopped, the FDA said in a statement.
“This small increased risk of higher blood-sugar levels needs to be taken in the context of the very strong evidence of beneficial things that are provided by statins,” Matthew Price, director of the cardiac catheterization laboratory at Scripps Clinic in La Jolla, California, said in a telephone interview. “This doesn’t affect my prescribing of statins where it’s clinically indicated, though I will make sure I closely follow patients at risk for diabetes.”
Statins work by blocking a substance the body needs to make cholesterol and may help the body reabsorb cholesterol built up on artery walls that can cause heart attacks, according to the Mayo Clinic. Lipitor, the world’s top-selling medicine with about $9.6 billion in 2011 revenue, lost U.S. patent protection last year and generic versions of the medicine are on the market.
Research the past two years linked the cholesterol-lowering medicines to Type 2 diabetes, the most-common form of the disease associated with obesity. A 2010 study in The Lancet, a U.K. medical journal, found a slight increase in the instance of diabetes and, last June, a report in the New England Journal of Medicine found an added risk of diabetes in those taking high doses of statins.
Diabetes affects more than 20 million Americans, according to the National Institutes of Health. The condition is caused by too little insulin and resistance to insulin, a hormone produced by the pancreas to control blood sugar.
While statins raise blood sugar, they reduce the risk of heart attacks even in diabetics, the researchers found.
“We want health-care professionals and patients to have the most-current information on the risks of statins, but also to assure them that these medications continue to provide an important health benefit of lowering cholesterol,” said Mary Parks, director of FDA’s division of metabolism and endocrinology products.
Effect on Blood Sugar
Giving a statin to people who already have elevated blood-sugar levels may push them into the diabetic range, even if it’s only a tiny increase, said Steven Nissen, head of cardiology at the Cleveland Clinic in Ohio. Those patients still would reap heart benefits from lowering their cholesterol as do people who don’t develop diabetes, he said.
“Accordingly, the diabetes risk does not outweigh the benefits of statins,” he said. “For the vast majority of patients, the benefits greatly outweigh the risks.”
The removal of the requirement for liver function testing “is long overdue,” Nissen said.
“There are few, if any, cases where statins have been implicated in liver injury,” he said. “Regular testing is an anachronism.”
The label changes underscore the need for more personalized medicine, said Eric Topol, director of the Scripps Translational Science Institute. The drugs can trigger diabetes in 1 in 200 patients, he said. Analyzing the genetic makeup of people on statins, and identifying those who are most vulnerable, would improve patient safety.
“With tens of millions of people taking statins, that’s a significant number of people,” Topol said in a telephone interview. “That’s why we need to know the genomics. Then we could use the drug for its benefits and not worry about inducing diabetes.”