Simvastatin is a commonly prescribed member of the statin drugs. These drugs are often used to treat high cholesterol because they prevent the liver from synthesizing new cholesterol. Statins are some of the most effective medications for lowering cholesterol, but they are often taken for life, which means that some patients may be unable to take simvastatin due to its side effects, MayoClinic.com reports.
Simvastatin can cause irritation of the gastrointestinal tract. In some patients, this manifests as chronic indigestion, which is also known as dyspepsia, eMedTV explains. Simvastatin can also cause abdominal pain. The frequency of bowel movements may also be altered, which can result in either diarrhea or constipation.
Central Nervous System Dysfunction
Patients who take simvastatin can also experience some problems due to the effects of the medication on the brain. The most common manifestation, which occurs in approximately 6.5 percent of patients, is a headache. In other cases, patients develop vertigo, tremors, memory loss and paralysis of parts of the body.
Patients taking simvastatin are prone to developing infections of the respiratory tract. This can result in inflammation of the sinuses, which is also known as sinusitis, or inflammation of the airways, which is commonly referred to as bronchitis.
Simvastatin can also cause inflammation of the muscles and muscle pain. The milder forms of this side effect are called myositis or dermatomyositis. Patients may also notice that they develop muscle cramps or experience muscle fatigue more easily. In more severe cases, however, rhabdomyolysis may occur. Rhabdomyolysis is potentially life-threatening condition in which the muscle cells are destroyed. When this happens, severe muscle pain occurs, and the liver and kidneys may become damaged. Rhabdomyolysis is more likely in patients who take high doses of simvastatin or who take certain other medications along with simvastatin, MayoClinic.com states.
Rash and Flushing
A rash or flushing may also occur after taking simvastatin. Patients are more likely to experience this side effect if they take simvastatin along with niacin, which is another medication which treats high cholesterol levels.
Increased Liver Enzymes
Simvastatin can stimulate the liver to increase its production of certain proteins known as enzymes. This increase in liver enzyme levels can be detected via blood testing. Mild elevations of these enzyme levels does not cause any serious problems. Severe increases in liver enzyme production, however, can damage the liver. This liver damage is a particularly troublesome side effect because it can occur without any symptoms, MayoClinic.com explains, which means that the only way to detect this potentially life-threatening complication before it causes liver failure is to regularly test the patient's liver enzyme levels in the blood.