Medications known as statins are called hypolipidemic drugs, which means that they lower cholesterol levels. Some people experience a connection between taking simvastatin and muscle pain, which may be mild or excruciating depending on the individual. This side effect is actually common to all statin drugs.
Estimates vary as to what percentage of people taking simvastatin for high cholesterol actually experience this side effect. Studies performed by drug manufacturers generally state that about 3% of individuals taking this medication will experience some level of muscle pain. Doctors treating patients with simvastatin sometimes believe that this proportion is somewhat higher, and may occur in 10% to 15% of people taking this hypolipidemic drug.
For most individuals, the link between simvastatin and muscle pain does not predict worse health problems. A feeling of sore or tired muscles is how this side effect most commonly manifests, although some people have trouble performing day-to-day activities as a result. Occasionally, however, this pain may become worse over time, or even lead to muscle damage. Blood tests can help show whether the pain is being caused by muscle damage.
In the most extreme cases, having a regular regimen of simvastatin and muscle pain may indicate serious health issues. A condition involving the degradation of skeletal muscle, called rhabdomyolysis, may rarely result from using this medication. Another health problem called myositis, or the inflammation of muscle, can result from chronic use.
There is a genetic component that may underlie the connection between taking simvastatin and muscle pain, at least in some cases. People with one or two copies of a certain genetic variant taking this hypolipidemic drug were investigated in one study. Researchers found that one copy of this deoxyribonucleic acid (DNA) variant were 5 times as likely to have muscle problems as people without the variant present. Individuals with two copies of the DNA variant were up to 16 times as likely to develop muscle pain and weakness.
Aside from a genetic risk, there are other factors that may predict whether a person taking this medication will experience muscle pain. Certain drugs, when combined with simvastatin, increase the risk of muscle damage. Long-term, high doses of this medication may be more likely to result in damage, as well. For this reason, some countries have instituted guidelines that set a maximum recommended dosage of this drug to be taken each day. In the United States, this maximum dosage is 80 milligrams.