Statins are a class of cholesterol-lowering medications known as HMG-CoA reductase inhibitors. These play a very important role in people with elevated cholesterol in assisting in cardiovascular health. Lowering circulating cholesterol decreases your risk of developing atherosclerosis or hardening of the arteries, heart attacks and stroke. They are considered an effective treatment; however, like all cholesterol-lowering medications, there are potential side effects.
Liver Damage
The use of HMG-CoA reductase inhibitors or statins has been linked to liver damage if it is not monitored closely. Statins work in the liver and can accumulate in large amounts. This accumulation can overwhelm the liver, leading to elevations in enzymes that the liver produces. If left unchecked, the liver can become permanently damaged, resulting in liver failure.
Gastrointestinal Issues
While rare, the gastrointestinal side effects of statins are not as significant as some of the others. People taking statins have reported nausea, stomach upset, constipation and increased flatulence as side effects.
Rashes
Rashes that have been associated with the use of statins can be mild, such as an itchy red rash, to a severe rash called Stevens-Johnson syndrome, a condition leading to large amounts of skin sloughing and associated infection. This is an emergency medical condition requiring immediate attention.
Muscle Damage
According to MayoClinic.com, statins have been found to cause breakdown of muscle mass as one of its possible side effects. This breakdown releases protein into the bloodstream from the damaged muscle. If breakdown occurs in large enough quantities, the proteins released can clog the kidneys and liver, resulting in organ failure. This process is called rhabdomyolysis and is considered a very serious condition.
Nervous System
A variety of nervous system side effects have been reported with the use of statins. Some side effects include headaches, tremors and numbness. More serious side effects that have been reported but not yet linked to the use of statins include memory loss and Lou Gehrig's disease or amyotrophic lateral sclerosis, a progressive muscle-strength weakening disorder.


