Lipids, or fats, are made naturally in your body from the food you eat. They are easily stored in your body and serve as a source of energy. Cholesterol and triglycerides are types of lipid. If the concentration of these lipids in your blood becomes too high, it leads to a condition called hyperlipidaemia. If it is the concentration of cholesterol which has become too high, it is called hypercholesterolaemia. Although a high blood concentration of lipids will not make you feel ill, it can cause a problem if it is left untreated.

People with high lipid levels can develop small fatty patches called atheroma. These patches develop when excess fat is deposited on to the walls of blood vessels. Over time, these patches can make a blood vessel narrower and this is called atherosclerosis (sometimes referred to as 'hardening of the arteries'). The narrowing reduces the blood flow through the artery and increases the risk of a number of heart and blood vessel diseases, such as heart attack, stroke and Raynaud's.

Simvastatin belongs to a group of medicines known as statins (or HMG-CoA reductase inhibitors). It regulates the amount of cholesterol and other lipids made by your body. It does this by blocking the action of a certain enzyme (called HMG-CoA reductase) which your body needs to make the fats. This lowers your risk of heart and blood vessel disease. It can also reduce this risk, even if your cholesterol levels are normal, if you are at an increased risk of heart disease as a result of other healthcare problems (such as if you have diabetes mellitus).

Simvastatin is available on prescription. The 10 mg strength tablets are also available to buy without a prescription at a pharmacy if you have been advised by a healthcare professional that simvastatin should form part of a programme of treatment to reduce your risk of heart disease.

Before taking Simvastatin

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking simvastatin it is important that your doctor knows:

  • If you are pregnant, trying for a baby or breast-feeding.
  • If you have any problems with the way your liver works, or if you have ever had a disease which has affected your liver.
  • If you have an underactive thyroid.
  • If you have a problem with unexplained muscle aches or pains, or if you (or a close relative) have ever had a muscle disorder.
  • If you regularly drink large amounts of alcohol.
  • If you have any problems with the way your kidneys work.
  • If you have ever had an allergic reaction to a medicine.
  • If you are taking any other medicines. This is particularly important because there are a number of medicines that should not be taken with simvastatin, and there are also some medicines that will affect the dose of simvastatin that your doctor prescribes for you. Please also make sure that your doctor knows of any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.

How to take Simvastatin

  • Before you start the treatment, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about simvastatin and will provide you with a full list of the side-effects which you may experience from taking it.
  • Take one dose of simvastatin each day, in the evening. There are several different strengths of tablet available (10 mg, 20 mg, 40 mg and 80 mg) - your doctor will tell you which strength of tablet is right for you. Swallow the tablet with a drink of water. If you have any difficulties swallowing, let your doctor know about this as a liquid medicine may be more suitable for you.
  • You can take simvastatin before or after food.
  • Do not drink grapefruit juice at any time while you are taking simvastatin. This is because a chemical in grapefruit juice increases the amount of simvastatin in your bloodstream. This makes side-effects more likely and increases the risk of them being more serious.
  • If you forget to take a dose, leave out the missed dose but make sure that you remember to take your next dose on the following evening. Do not take two doses together to make up for a forgotten dose.

Getting the most from your treatment

  • Try to keep your regular appointments with your doctor. This is so that your doctor can check on your progress. You will need to have some blood tests from time to time. These are to measure your lipid levels and also to check that your liver has not been affected by taking simvastatin.
  • Your doctor will give you advice about eating a healthy diet, cutting down on the amount of alcohol you normally drink, reducing the amount of salt in your diet, stopping smoking and taking regular exercise. Following this advice will also help you to reduce your risk of developing heart and blood vessel disease.
  • Women taking simvastatin must avoid getting pregnant. Make sure you have discussed with your doctor which types of contraception are suitable for you and your partner.
  • Treatment with simvastatin is usually long-term unless you experience an adverse effect. You should continue to take it regularly.

Can simvastatin cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the side-effects associated with simvastatin, although these tend to occur only rarely and are usually mild in nature. You will find a full list in the manufacturer's information leaflet supplied with your medicine. Unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.

Simvastatin side-effects (these affect less than 1 in 1,000 people) and what to do.

Muscle cramp, pain or tenderness - Although this may not be anything to be concerned about, you should tell your doctor about this. This is because there is a rare but serious side-effect of simvastatin which is a severe form of muscle inflammation.

Headache - Ask your pharmacist to recommend a suitable painkiller

Feeling sick, indigestion, wind (flatulence), stomach upset - Stick to simple meals - avoid rich or spicy food

Feeling dizzy or tired, tingling feelings, itchy rash, hair thinning - Speak with your doctor if any of these become troublesome

Important: simvastatin has been associated with some more serious side-effects in a very few people. Although these occur only rarely, it is important that you tell your doctor straightaway if you experience any of the following symptoms:

  • If you develop any muscle cramps or pains, particularly if they are in your legs and you also feel unwell or have a high temperature (fever).
  • If you feel short of breath or develop an unexplained cough. This is because (in very rare cases) statin medicines like simvastatin can cause a disease called interstitial lung disease.
  • If you develop any allergic-type reactions, such as swelling around your mouth or face, or a skin rash.

If you experience any other symptoms which you think may be due to simvastatin, speak with your doctor or pharmacist for further advice.

How to store simvastatin

  • Keep all medicines out of the reach and sight of children.
  • Store in a cool, dry place, away from direct heat and light.
  • The oral liquid medicine may be used for one month once the bottle has been opened. After this time, get a fresh supply.