Q. My doctor used to check my liver function once a year after I started taking a statin drug to lower my cholesterol, but he doesn't anymore. Why not?
A. Your doctor appears to be following the latest recommendations from the American Heart Association and the FDA. When statin medications were first approved, doctors did periodic blood tests to check for liver injury. Three decades later, it is clear that serious liver injury from statins is a rare side effect and that routine blood testing does not help identify people at risk for statin-related liver problems. Therefore, routine monitoring is not a good use of money and time.
Studies of very large numbers of people estimate that among those taking a statin, only one in 1,000 of them would have an abnormal liver test result attributable to the medication. Other studies found that abnormal test results were about as common in people who took a statin or a placebo. Since statins cause so few liver problems, and many other things—such as viral infections and drinking alcohol—can affect liver tests, most abnormal liver test results in people taking statins are unrelated.
There have been rare reports of serious liver problems associated with statins, but the people this happens to often have liver disease already or were also taking other medications that worsen the effect of statins on the liver. Therefore, a single baseline liver test is recommended before starting on a statin, and periodic checks might be continued in people at high risk of problems.
— William Kormos, M.D.
Editor in Chief, Harvard Men's Health Watch