By the way, doctor: Can you tell me about the tests for liver and muscle side effects from statins?
Q. I am 80 and am taking a 40-milligram Crestor pill every day. Recently I saw a Crestor ad that said blood tests should be done to monitor for the possible side effects of liver or muscle injury. Can you tell me something about these tests?
A. Crestor (the brand name for rosuvastatin) is a cholesterol-lowering statin like atorvastatin (Lipitor) and simvastatin (Zocor). All of the statins can injure the liver and muscle tissue, but, fortunately, it's a rare occurrence. Here is what you and your doctor need to look for.
As you might expect, statins are more likely to cause liver injury if you have a liver problem of some kind already — or if you consume large amounts of alcohol. Injured liver cells spill certain enzymes into the blood, so elevated levels of those enzymes in the blood are a good indication of a liver problem. The tests to detect those enzymes are pretty straightforward these days. The two most commonly ordered tests measure alanine aminotransferase and aspartate aminotransferase. Serious liver damage will produce noticeable, if vague, symptoms, such as poor appetite, nausea, and fatigue.