Simvastatin is an enzyme blocker (HMG-CoA reductase inhibitor), also known as a "statin". It is used along with a proper diet to help lower cholesterol and fats (triglycerides) in the blood. In general, this drug is prescribed after non-drug treatment options have not been fully successful at lowering cholesterol (e.g., diet change, increase in exercise, weight loss if overweight). Reducing cholesterol and triglycerides help prevent strokes and heart attacks. Simvastatin is used in adults and children (10 years of age and older). Young girls must have had their menstrual periods for at least one year before starting this medication.

Take this medication by mouth usually once daily in the evening, with or without food. Certain medical conditions (e.g., familial hypercholesterolemia) may require more frequent dosage instructions as directed by your doctor. Dosage is based on your medical condition, response to therapy, and use of certain interacting medicines. Many of the drugs listed in the Drug Interactions section may increase the chances of muscle injury when used with simvastatin. Consult your doctor or pharmacist for more details. Avoid eating grapefruit or drinking grapefruit juice while being treated with this medication unless your doctor instructs you otherwise. Grapefruit juice can increase the amount of certain medications in your bloodstream. Consult your doctor or pharmacist for more details. If you also take certain other drugs to lower your cholesterol (bile acid-binding resins such as cholestyramine or colestipol), take simvastatin at least 1 hour before or at least 2 hours after these medications. Use this medication regularly in order to get the most benefit from it. Remember to use it at the same time each day. It may take up to 4 weeks before the full benefit of this drug takes effect. It is important to continue taking this medication even if you feel well. Most people with high cholesterol or triglycerides do not feel sick.

Before taking simvastatin, tell your doctor or pharmacist if you are allergic to it; or to other "statins"; or if you have any other allergies. This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: active liver disease. Before using this medication, tell your doctor or pharmacist your medical history, especially of: history of liver disease, kidney disease, alcohol use. Before having surgery, tell your doctor or dentist that you are taking this medication. Limit alcoholic beverages. Daily use of alcohol may increase your chance for serious side effects. Caution is advised when using this drug in the elderly because they may be more sensitive to the side effects of the drug, especially muscle damage. This medication must not be used during pregnancy. If you become pregnant or think you may be pregnant, inform your doctor immediately. It is recommended that young girls and women of child-bearing age use effective birth control measures to prevent pregnancy while taking this drug since simvastatin may cause harm to an unborn baby. It is not known if this drug passes into breast milk. Because of the potential risk of undesirable effects on a nursing infant, breast-feeding is not recommended while using this drug. Consult your doctor before breast-feeding.

If you miss a dose, use it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with them first. See also the How To Use section. This drug should not be used with the following medications because very serious, possibly fatal interactions may occur: certain azole antifungals (e.g., itraconazole, ketoconazole), delavirdine, HIV protease inhibitors (e.g., ritonavir, amprenavir, lopinavir), certain macrolide antibiotics (e.g., erythromycin, clarithromycin, troleandomycin), nefazodone, telithromycin. If you are currently using any of these medications, tell your doctor or pharmacist before starting simvastatin. Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: "blood thinners" (e.g., warfarin), cholestyramine, colestipol, danazol, daptomycin, digoxin, other drugs which affect certain liver enzymes (CYP 3A4 substrates, inhibitors, and inducers such as amiodarone, cyclosporine, diltiazem, verapamil, rifampin, St. John's wort, carbamazepine). This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.

Stomach upset may occur. If this effect persists or worsens, notify your doctor or pharmacist promptly. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. This drug may infrequently cause muscle problems (which can rarely lead to a very serious condition called rhabdomyolysis). Tell your doctor immediately if you develop any of these symptoms: muscle pain/tenderness/weakness (especially with fever or unusual tiredness), change in the amount of urine. Tell your doctor immediately if any of these highly unlikely but very serious side effects occur: yellowing eyes and skin, dark urine, severe fatigue, stomach/abdominal pain, persistent nausea. A serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction include: rash, itching/swelling (especially of the face/tongue/throat), dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Store between 41 and 86 degrees F (5 and 30 degrees C) away from light and moisture. Do not store in the bathroom. Keep all medicines away from children and pets. Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.