FDA changes safety information on statin drugs

Howard LeWine, M.D.

Chief Medical Editor, Harvard Health Publishing

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A new ruling from the FDA offers good news and some warnings for people who take a cholesterol-lowering statin. The good news—no more periodic blood tests for liver function. The warnings—taking a statin may increase the odds of developing type 2 diabetes or suffering reversible memory loss or problems thinking. The FDA warned that one statin, lovastatin, shouldn’t be taken with some antibiotics, anti-fungal agents, or medications used to treat AIDS.

The statins are a family of medications used to lower cholesterol. Millions of people take one. The family currently includes atorvastatin (generic, Lipitor), fluvastatin (Lescol), lovastatin (generic, Mevacor, Altoprev), pitavastatin (Livalo), pravastatin (generic, Pravachol), rosuvastatin (Crestor), and simvastatin (generic, Zocor).

Liver testing

When the FDA approved the first statins in the late 1980s, doctors were told to do periodic blood tests on anyone taking a statin to look for early signs of liver trouble. Millions of statin users later, it’s clear that liver damage is extremely rare. It also can’t be predicted by checking liver tests every few months.

The FDA now says that you should have a liver function test soon after starting to take a statin or after switching to a new one. If everything is fine, no further blood test is needed unless a problem arises.

Blood sugar

In some clinical trials, participants who took a statin were more likely to develop higher blood sugar than those taking a placebo. In two meta-analyses of data from these trials, the increases were 6% to 13%. Whether this translates into type 2 diabetes is as-yet unknown. Based on these findings, the FDA is warning that statin use increases blood sugar or glycosylated hemoglobin (HbA1c) levels in some people. HbA1c is a measure of a person’s average blood sugar level over a three-month period.

Memory loss

Memory loss is another possible side effect the FDA is now warning about. Occasional reports in the FDA’s Adverse Event Reporting System (AERS) tell the story of mostly older men and women who experience memory loss or changes in thinking skills after starting a statin, only to have it disappear after stopping the drug. In some, the problem began within days of starting the drug; in others it began years afterward. Results from observational studies and clinical trials, though, offer no evidence that statin use causes permanent long-term thinking or memory problems. And several studies looking at the relationship between dementia and statins suggest the opposite—that taking a statin lowers the risk of dementia.

Lovastatin interactions

An enzyme called CYP3A4 helps break down lovastatin (generic, Mevacor, Altoprev). Drugs that inhibit the activity of this enzyme can let lovastatin build up in circulation, which can lead to severe muscle problems. Based on new data, the FDA is warning people not to take lovastatin at the same time they are taking certain drugs that inhibit CYP3A4. These include:

  • itraconazole
  • ketoconazole
  • erythromycin
  • clarithromycin
  • telithromycin
  • an HIV protease inhibitor
  • nefazodone

Only lower doses of lovastatin should be taken with gemfibrozil, high-dose niacin, cyclosporine, amiodarone, and verapamil.

Using statins safely

The FDA is correct in warning us of the possibility that statins may cause memory loss or increase blood sugar. Even if later data show neither is true, better safe than sorry.

But don’t stop taking your statin based on these FDA warnings. I’m definitely going to keep taking mine. If you are worried, though, talk with your doctor. If your cholesterol is only borderline high without a statin, then maybe it makes more sense for you to try diet and exercise to get it (and the rest of you) in shape.

I tell all of my patients who start a statin, increase its dose, or switch to a different one that they should stop the drug and call for advice if they:

  • develop weak or very achy muscles (possible muscle damage)
  • notice that their eyes or skin turn yellow or their urine turns brown (possible liver damage).

Because of the new FDA alerts, I’ll advise my statin-taking patients to be on the lookout for problems if they add a new antibiotic or other medication. I’ll also recommend that they call for advice if they develop sudden memory loss, which they would likely do anyway. But I won’t blame the statin until I have looked for more common reasons for memory loss.

Related Information: What to do about High Cholesterol


  1. paul hill

    One side effect of statins that struck me was type 2 diabetes, 2 presumably being associated with weight gain. Now the diagnostic test of diabetes is as good as useless, 1.75 grammes of glucose per Kg of body weight taken at 9 am after a fast from the previous evening and after taking the first blood test, then one EACH HOUR, three all up. Now I’ve done quite a few 5 hr GTT’s and I found that I HAD to do a test each 15 minutes to start off or miss the peak. One woman I tested went from around 6.5 to SIXTEEN then fell to a low of 4 (a 400% fall) in a bit over an hour and had glucose in her urine. Ok, the standard test will detect glucose in urine but that peak is every bit as important as far as arteriosclerosis is concerned because the arteriosclerosis of diabetes is every bit as much about hyperglycaemia as it is about hypercholestertolemia. It called non-enzymatic glycosation of protein, glucose acting like a glue binding to proteins on epithelial cells lining blood vessels and trapping cholesterol in this glue.
    Now looking at the metabolic pathways the central molecule is acetyle Co enzyme A or acetyl CoA (vinegar with an enzyme) the CENTRAL molecule of all major metabolic pathways in almost all cells. Ethanol (alcohol) is converted to acetyle Co A (via acetaldehyde), as are ketones from the breakdown of fatty acids. But the liver doesn’t import fatty acids to convert to ketones except with ketosis. However, look up what’s called the glycolytic pathway and you’ll see glucose coming in from one side, Here it can go up to be synthesised to glycogen, the storage form of glucose. Come back down to acetyle CoA and it can enter the TCA or citric acid cycle to make energy in the form of ATP, as well as intermediate molecules in the TCA cycle. But too much acetyle CoA into the TCA cycle and citric acid builds up and it inhibits glycolysis, But what happens if glycogen stores are topped to the brim, made worse by liver pathology limiting storage and no more energy production is needed other than a base level to keep the cell running. There is ONLY one way out, turn acetyle CoA into cholesterol. So the synthesis of excess cholesterol is an emergency BLOOD SUGAR REGULATING MECHANISM that would lower osmotic blood pressure etc. Block it and up goes blood glucose, DIABETES. Neat eh!! According to this irrefutable hypothesis cut back on the carb intake and the blood cholesterol level will come down accordingly so you can flush the statins down the loo where they belong.

  2. Robert Cannon

    What really matters is whether cholesterol is as bad as assumed. That’s right- it is an assumption. We need to see data showing the number of heart attacks and deaths vs LDL, HDL and Total Cholesterol levels. Then we need to see the CRP levels- a measure of inflammation. Then data with and without statins. I predict you will find that those with high CRP (inflammation) have the higher heart attack death rates, not those with high cholesterol levels. And those that take statins that have high CRP have lower death rates. Then there is research showing that statins have an antiinflammatory benefit, which is the true cause of the select benefits in those with increased inflammation, and the amount of statin needed to get most of that benefit is fractional of current dosages, just a few milligrams, with no side effects. But one can get the same benefit by eating more vegetables and less vegetable oil (inflammatory omega 6 oils found in plaques). Data has shown that lowering LDL is not beneficial and increases pneumonias and other deaths. Please be more thorough in your reporting. You are steering people in the wrong direction.

  3. Constipation

    my father passed away when i’m 15 years old. he had problem with his liver. Now, i am very excited information about health for Liver. and i won’t like my father. thanks 😀

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