The Story: The Boston Globe on February 25, 2008 cited a recent paper in the journal Nature Biotechology that indicated that certain statin medications (used for control of high cholesterol) might impair the functioning of critical cellular components called mitochondria. The mitochondria are tiny structures that generate the necessary energy (in the form of a substance called ATP) for our cells to work–sort of our own intracellular power company. Certain statins, namely simvastatin (Zocor), lovastatin (formerly Mevacor), and fluvastatin (Lescol) seemed to impair the production of ATP much more than others, specifically atorvastatin (Lipitor), rosuvastatin (Crestor), and pravastatin (Pravachol) . These findings were produced in laboratory-grown muscle cells, and not in live human beings.
What to Think? This laboratory information is tantalizing, but not yet compelling, for a number of reasons. It does seem to offer a mechanism for the muscle fatigue experienced by a small portion of people who use statin medications for cholesterol control. Doctors know this happens, without necessarily showing up in any standard blood tests. But muscle fatigue can be experienced by people taking any of the statins named above. It is not clear that there is a preponderance of problems with, for example, simvastatin v. atorvastatin. Nor is there yet a clinical way to test for subtle mitochondrial problems in real people, as opposed to a literal test tube.
What to Do? At the moment I would not change any prescribing patterns. If you are taking any statin and feel well and your achieved cholesterol levels are good, there certainly is nothing to do. If, however, you or another of my patients were to develop muscle fatigue on simvastatin, I would certainly look toward Lipitor, Pravachol, or Crestor as the drugs to try next to control the cholesterol without, we would hope, encountering muscle fatigue. Nevertheless, this is an intriguing development, which we will follow with interest. There undoubtedly will be follow-ons.