Simvastatin
1 medicine
Simvastatin is a statin that lowers LDL cholesterol to reduce the risk of heart attack and stroke. Grapefruit juice and certain heart and antifungal medicines raise its levels and the risk of serious muscle breakdown, so doses are often capped when combined.
Key facts
- Simvastatin is a statin, usually taken in the evening, that lowers LDL cholesterol and reduces the risk of heart attack and stroke over time.
- Grapefruit and grapefruit juice raise simvastatin levels significantly. Avoid them, since higher levels increase the risk of muscle damage.
- Rhabdomyolysis, serious breakdown of muscle tissue, is the main serious risk. Muscle pain or weakness together with dark urine is the warning sign and needs same-day medical attention.
- Amiodarone, verapamil, diltiazem, certain antifungals, and some antibiotics raise simvastatin levels so much that your dose is capped, sometimes far below the usual maximum, or the combination is avoided altogether.
What simvastatin treats
Simvastatin treats high LDL cholesterol and mixed dyslipidaemia, and it reduces the risk of heart attack and stroke in adults with cardiovascular risk factors or established heart disease. It also treats familial hypercholesterolaemia.
How simvastatin works
Simvastatin blocks HMG-CoA reductase, the enzyme the liver uses to make cholesterol. With production reduced, the liver removes more LDL cholesterol from the blood to compensate, lowering the level measured on your cholesterol test.
Before you take it
- Avoid simvastatin in pregnancy and breastfeeding, since cholesterol is needed for fetal development.
- Tell your prescriber about liver disease or a history of muscle disorders.
- Avoid grapefruit and grapefruit juice. They block the enzyme that clears simvastatin from your body and raise its level.
- List every medicine you take. Amiodarone, verapamil, diltiazem, certain antifungals (such as itraconazole and ketoconazole), some antibiotics (such as clarithromycin and erythromycin), and some HIV medicines raise simvastatin levels substantially. Depending on the combination, your maximum dose may be capped well below the usual limit, or simvastatin may not be suitable at all.
Side effects
Common effects include headache, mild digestive upset, and muscle aches.
Seek urgent medical care for:
- Muscle pain or weakness you can't explain, especially with dark, tea-coloured urine.
- Yellowing of the skin or eyes, or persistent abdominal pain.
- Signs of an allergic reaction, such as swelling or difficulty breathing.
Safety essentials
- Simvastatin's dose has fixed ceilings when combined with certain drugs. With amiodarone or verapamil, for example, the maximum dose is much lower than usual, and with some antifungals or protease inhibitors, simvastatin should not be used at all. Tell your prescriber and pharmacist about every medicine before starting or refilling.
- Avoid grapefruit and grapefruit juice: they raise blood levels of simvastatin and increase the risk of muscle damage.
- Know the warning sign: muscle pain or weakness together with dark urine can mean rhabdomyolysis. Stop the medicine and get same-day medical care if this happens.
- Liver-enzyme blood tests are checked before you start and periodically during treatment, and simvastatin is avoided in pregnancy and breastfeeding.
This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.