Simvastatin

Sounds like 'sim-va-stat-in'

Key points about simvastatin

  • Simvastatin is used to lower raised cholesterol and reduce your chance of heart disease and stroke.
  • Find out how to take it safely and possible side effects.
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Simvastatin is a medicine that reduces the amount of cholesterol made by your body by blocking the action of a certain enzyme which is needed to make cholesterol. It belongs to a group of medicines known as statins.

If you have high cholesterol

Simvastatin is used to lower raised cholesterol. Having high cholesterol increases your risk of cardiovascular disease and having a heart attack or stroke. Read more about high cholesterol.

  • Cholesterol is a type of lipid that is made by your liver and from the fatty foods that you eat. Everyone has cholesterol and triglycerides in their blood. They are fatty substances needed by the body for many things.
  • Your body needs some cholesterol but if the amount in your blood gets too high, it can cause small fatty patches called plaques (or atheroma).
  • Over time, these patches can accumulate and make the blood vessels narrow and stiff (a process called atherosclerosis). The narrowing reduces the blood flow through the arteries and can cause heart attack, angina and stroke.
  • Simvastatin helps to reduce atherosclerosis and reduces your risk of having a heart attack or stroke.

In people with normal cholesterol but at risk of heart disease and stroke

Simvastatin can also reduce your chance of heart disease and stroke if you have an increased risk of it, even if your cholesterol levels are normal.

  • When deciding whether you should take a statin or not, your doctor will look at your overall risk of having a heart attack or stroke in the future.
  • They use calculations to work out your individual risk, including information on your age, sex, ethnicity, blood pressure, whether you smoke and if you have diabetes. Read more about heart risk assessment.
  • If your overall risk of having a heart attack or stroke is high, regardless of your cholesterol level, a statin may be recommended. This is because even if the amount of cholesterol in your blood is normal according to the numbers on your blood test results, there may already be plaque present in your arteries that indicates you’re at risk of cardiovascular disease.
  • Note: Taking a statin, such as simvastatin is just one factor in reducing your risk of cardiovascular disease. Making lifestyle changes including eating a healthy diet, staying active, keeping a healthy weight, drinking less alcohol, and not smoking can also reduce your risk of cardiovascular disease.

Simvastatin tablets are available in different strengths: 10 mg, 20 mg, 40 mg and 80 mg. Your dose of simvastatin will depend on why you are taking it, your cholesterol levels, and other medicines you may be taking.

  • For high cholesterol: The usual dose is 10 mg or 20 mg once a day, at night. Depending on your cholesterol levels, your doctor may increase your dose after a few weeks to 40 mg at night. People with very high cholesterol levels may be prescribed a higher dose of 80 mg a day.
  • To prevent heart attacks and strokes: The usual dose is 20 mg or 40 mg once a day, at night. People with very high cholesterol levels may be prescribed a higher dose of 80 mg a day.
  • Always take your simvastatin exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much simvastatin to take, how often to take it, and any special instructions.

  • Timing: Take simvastatin once a day. Some people may recommend taking simvastatin in the evening, but there is little difference in effect. In general, the best time to take it is at a convenient time that suits you so that you remember to take it. It's best to take it at the same time each day.
  • Food: You can take simvastatin with or without food.
  • Missed dose: If you forget your dose, take it as soon as you remember that day. But, if it is nearly time for your next dose, just take the next dose at the usual time. Do not take double the dose.

Here are some things to know when you're taking simvastatin. Other things may be important as well, so ask your healthcare provider what you should know about.

  • Alcohol: Avoid drinking large amounts of alcohol while you're taking simvastatin. Heavy drinking can increase your risk of side effects such as problems with your liver.
  • Avoid large quantities of grapefruit: Having large quantities of grapefruit while taking simvastatin can increase your risk of side effects. But eating 1 serving of marmalade, no more than half a grapefruit or drinking no more than a standard glass (250 mL) of grapefruit juice each day, shouldn't be a problem. It's best to allow 12 hours between having these foods and taking your simvastatin dose, so if you take your statin in the morning have your grapefruit at night.
  • Tests and monitoring: You may need to see your healthcare provider regularly when you first start taking simvastatin to make sure the dose is right for you. High cholesterol doesn’t have any symptoms so you won’t notice any changes after taking simvastatin. That's why it’s important to have a blood test to check the changes in your cholesterol levels.
  • Keep taking simvastatin regularly: To reduce your cholesterol effectively, you must keep taking simvastatin every day. Treatment with simvastatin is usually long term.
  • Get the full benefit: To get the full benefit of a statin, it's important to eat a healthy diet, exercise regularly and have no more than 1 alcoholic drink a day. It's best to eat a low-fat diet, and reduce the amount of saturated fat you eat.
  • Other medicines: Simvastatin interacts with some medicines, herbal supplements and rongoā Māori, so check with your healthcare provider or pharmacist before starting simvastatin or before starting any new medicines or supplements.
  • Pregnancy or breastfeeding: Talk to your healthcare provider if you're pregnant, planning a pregnancy or want to breastfeed.

Like all medicines, simvastatin can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Muscle pain or weakness

Some people will have muscle pain or weakness when taking statins. This is rarely serious and often goes away with time. If your pain comes on shortly after you start your statin, or gets worse, see your doctor. Your doctor will check an enzyme called creatine kinase to see if the aches and pains are possibly being caused or made worse by the statins. If so:

  • a lower dose or a different statin may be prescribed, or
  • you may choose to continue living with the aches because of the benefits of the statin, or
  • you may discuss stopping taking your statin with your doctor.

Your doctor will also want to check for a rare but serious condition called rhabdomyolysis and will check any other medicines you are taking. Rhabdomyolysis can be caused by an interaction between statins and some other medicines including antibiotics.

Other side effects

Side effects What should I do?
  • Diarrhoea (runny poo)
  • Stomach upset
  • Bloating or gas in the tummy
  • Nausea (feeling sick)
  • These are quite common when you first start taking simvastatin, and usually go away with time.
  • Tell your doctor if troublesome.
  • Muscle aches and pains or muscle weakness.
  • Dry cough, sudden weight loss and fever
  • Tell your doctor.
  • Signs of problems with your liver, such as dark-coloured urine, yellowing of the skin or eyes, sharp pain in your stomach area
  • Tell your doctor immediately or ring HealthLine 0800 611 116.
  • Signs of an allergic reaction, such as itchy skin and rash
  • Tell your doctor immediately or ring HealthLine 0800 611 116.
Read more about medicines and side effects and reporting a reaction you think might be a side effect.

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Credits: Sandra Ponen, Pharmacist, Healthify He Puna Waiora. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Angela Lambie, Pharmacist, Auckland

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