Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing, swelling of your face, lips, tongue, or throat. Stop taking simvastatin and call your doctor at once if you have any of these serious side effects: Unexplained muscle pain, tenderness, or weakness, fever, unusual tiredness, and dark colored urine, pain or burning when you urinate, swelling, weight gain, urinating less than usual or not at all, or nausea, upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes). Less serious side effects may include: headache, joint pain, mild muscle pain, constipation, stomach pain or indigestion, mild nausea, mild skin rash, sleep problems (insomnia), or cold symptoms such as stuffy nose, sneezing, sore throat.

Simvastatin is in a group of drugs called HMG CoA reductase inhibitors, or “statins.” Simvastatin reduces levels of “bad” cholesterol (low-density lipoprotein, or LDL) and triglycerides in the blood, while increasing levels of “good” cholesterol (high-density lipoprotein, or HDL). Simvastatin is used to lower cholesterol and triglycerides (types of fat) in the blood. Simvastatin is also used to lower the risk of stroke, heart attack, and other heart complications in people with diabetes, coronary heart disease, or other risk factors Simvastatin is used in adults and children who are at least 10 years old.