What are statin side effects?

Muscle pain and damage

One of the most common complaints of people taking statins is muscle pain. You may feel this pain as a soreness, tiredness or weakness in your muscles. The pain can be a mild discomfort, or it can be severe enough to make your daily activities difficult.

However, researchers have found a "nocebo" effect when it comes to perceived muscle pain and statins. A "nocebo" effect means people who have negative expectations about a medication report experiencing the potential side effect at higher rates than the drug should cause.

The actual risk of developing muscle pain as a result of taking statins is about 5 percent or less compared with taking a pill that doesn't contain medication (placebo). However, studies have found that nearly 30 percent of people stopped taking the pills because of muscle aches even when they were taking a placebo.

A strong predictor you'll experience muscle aches when taking statins could be whether or not you read about the potential side effect.

Very rarely, statins can cause life-threatening muscle damage called rhabdomyolysis (rab-doe-my-OL-ih-sis). Rhabdomyolysis can cause severe muscle pain, liver damage, kidney failure and death. The risk of very serious side effects is extremely low, and calculated in a few cases per million people taking statins. Rhabdomyolysis can occur when you take statins in combination with certain drugs or if you take a high dose of statins.

Liver damage

Occasionally, statin use could cause an increase in the level of enzymes that signal liver inflammation. If the increase is only mild, you can continue to take the drug. Rarely, if the increase is severe, you may need to try a different statin.

Although liver problems are rare, your doctor may order a liver enzyme test before or shortly after you begin to take a statin. You wouldn't need any additional liver enzyme tests unless you begin to have signs or symptoms of trouble with your liver.

Contact your doctor immediately if you have unusual fatigue or weakness, loss of appetite, pain in your upper abdomen, dark-colored urine, or yellowing of your skin or eyes.

Increased blood sugar or type 2 diabetes

It's possible your blood sugar (blood glucose) level may increase when you take a statin, which may lead to developing type 2 diabetes. The risk is small but important enough that the Food and Drug Administration (FDA) has issued a warning on statin labels regarding blood glucose levels and diabetes.

The increase generally occurs when blood sugar levels are already higher than normal and fall in the prediabetes or diabetes range when you begin taking a statin.

Statins prevent heart attacks in people with diabetes, so the relevance of the mild increase in sugar values with statins observed in some people is unclear. The benefit of taking statins likely outweighs the small risk to have the blood sugar level go up. Talk to your doctor if you have concerns.

Neurological side effects

The FDA warns on statin labels that some people have developed memory loss or confusion while taking statins. These side effects reverse once you stop taking the medication. There is limited evidence to prove a cause-effect relationship, but talk to your doctor if you experience memory loss or confusion while taking statins.

There has also been evidence that statins may help with brain function — in people with dementia, for example. This is still being studied. Don't stop taking your statin medication before talking to your doctor.