Zocor (simvastatin)

Main use	Active ingredient	Manufacturer
High cholesterol levels	Simvastatin	Merck Sharp & Dohme

How does it work?

Zocor tablets contain the active ingredient simvastatin, which is a type of medicine called a statin. Simvastatin is also available without a brand name, ie as the generic medicine. Simvastatin works by reducing the production of cholesterol by the liver.

For the sake of simplicity, there are two sorts of cholesterol; a 'bad' sort called low density lipoprotein (LDL) and a 'good' sort called high density lipoprotein (HDL). LDL is deposited in the arteries and increases the risk of heart disease by clogging and narrowing the arteries (atherosclerosis), while HDL actually protects the arteries against this.

Simvastatin decreases the production of LDL cholesterol by blocking the action of the enzyme in the liver (called HMG-CoA reductase) that is responsible for its production. This decreases the amount of cholesterol in the liver cells, which causes them to take up LDL cholesterol from the blood. The decreased cholesterol production and increased removal of LDL cholesterol from the blood ultimately results in lowered blood cholesterol levels.

As the body produces most cholesterol at night, statins are generally more effective if taken at night.

Simvastatin also causes a small decrease in the production of other 'bad fats' in the blood called triglycerides, and a small increase in the level of HDL cholesterol. This results in lowered levels of 'bad fats' and raised levels of 'good fats' in the blood.

Statins have an important role in the prevention of coronary heart disease. They reduce the risk of excess cholesterol being deposited in the major blood vessels of the heart (atherosclerosis). Any blockage in the blood vessels limits the amount of blood and therefore oxygen being carried to the heart muscle. This can cause chest pain (angina) and in severe cases can result in a heart attack (myocardial infarction).

Simvastatin is used to lower cholesterol in people who have high levels either due to genetics (familial hypercholesterolaemia) or as a result of diet and lifestyle. This helps to reduce the risk of atherosclerosis, angina and heart attacks (coronary heart disease).

Simvastatin can also be used to reduce the risk of coronary heart disease in people who have already had a heart attack, or who suffer from angina or diabetes. In these people simvastatin slows down hardening of the arteries, regardless of your cholesterol level. It reduces the risk of needing procedures to improve blood supply to the heart, such as a balloon dilation of an artery or a heart bypass graft. It also reduces the risk of heart attack and death.

It is important to follow a cholesterol-lowering diet and exercise regime while taking simvastatin. Discuss this with your doctor.

What is it used for?

• High blood cholesterol levels (primary hypercholesterolaemia).
• Inherited high blood cholesterol levels (familial hypercholesterolaemia).
• High levels of any or all of the fats in the blood, such as cholesterol, triglycerides and lipoproteins (mixed hyperlipidaemia).
• Reducing risk of death and illness from coronary heart disease in people who have had a heart attack, or who have angina or diabetes.

Warning!

• You should continue to follow a cholesterol-lowering diet during treatment with this medicine. Discuss this with your doctor.
• You should avoid drinking grapefruit juice while taking this medicine. This is because grapefruit juice can affect the metabolism of simvastatin and could increase the amount of the medicine in your blood, thus increasing the risk of side effects.
• It is recommended that you avoid drinking excessive amounts of alcohol while taking this medicine.
• This medicine may rarely cause liver problems. For this reason your doctor will want you to have blood tests to monitor your liver function (liver function tests) before starting treatment and regularly throughout treatment with this medicine. Consult your doctor promptly if you develop unexplained itching, yellowing of the skin or whites of the eyes (jaundice), unusually dark urine, nausea and vomiting, abdominal pains, loss of appetite or flu-like symptoms while taking this medicine, as these could be signs of a liver problem.
• This medicine may occasionally have side effects on the muscles. For this reason, you should inform your doctor immediately if you experience any unexplained muscular symptoms, such as pain, tenderness, cramps or weakness, while taking this medicine. Your doctor may need to check for side effects on the muscles by taking a blood test to measure the level of a compound called creatine kinase (CK) in your blood. If this is the case, the test should not be done following strenuous exercise.
• Statins may very rarely be associated with a type of lung disease. For this reason, you should consult your doctor if you experience shortness of breath or difficulty breathing, a non-productive cough and deterioration in your general health (eg weight loss, fever, fatigue) while taking this medicine.

Use with caution in

• People over 70 years of age.
• Decreased kidney function.
• Underactive thyroid gland (hypothyroidism).
• Personal or family history of hereditary muscle disorders.
• History of muscular side effects during previous treatment with a statin or fibrate medicine.
• History of liver disease.
• People who drink large quantities of alcohol.
• Hereditary blood disorders called porphyrias.

Not to be used in

• Active liver disease.
• People with unexplained raised results in liver function tests.
• Breastfeeding.
• Pregnancy.
• People taking the antifungals itraconazole or ketoconazole, the antibiotics erythromycin, clarithromycin or telithromycin, a protease inhibitor for HIV infection, or the antidepressant nefazodone.
• Rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption (Zocor tablets contain lactose).
• There is insufficient information regarding the safety and efficacy of this medicine in children. It is not recommended for children.

This medicine should not be used if you are allergic to any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.

If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

• This medicine should not used by women who are pregnant, trying to get pregnant, or suspect they could be pregnant, because it may be harmful to a developing foetus. Seek further medical advice from your doctor.
• It is not known if this medicine passes into breast milk. For this reason, the manufacturer states that it should not be taken by women who are breastfeeding. Seek medical advice from your doctor.

Side effects

Medicines and their possible side effects can affect individual people in different ways. Just because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect. The following are some of the side effects that are known to be associated with this medicine.

Rare (affect between 1 in 1000 and 1 in 10,000 people)

• Anaemia.
• Pins and needles (paraesthesia).
• Headache.
• Dizziness.
• Feeling of weakness.
• Disturbances of the gut, such as constipation, abdominal pain, flatulence, indigestion, diarrhoea, nausea and vomiting.
• Hepatitis(inflammation of the liver).
• Muscle breakdown (rhabdomyolysis).
• Inflammation of the muscles (myositis).
• Skin reactions such as rash or itching.
• Hair loss (alopecia).

Very rare (affect less than 1 in 10,000 people)

• Inflammation of the pancreas (pancreatitis).
• Memory loss.
• Difficulty sleeping (insomnia).

Unknown frequency

• Interstitial lung disease.
• Depression.
• Sleep disturbances.
• Sexual problems.

The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.

For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

It is important to tell your doctor what medicines you are taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to ensure that the combination is safe.

There may be an increased risk of side effects on the muscles (myopathy) if this medicine is taken with any of the following medicines:

• amiodarone
• ciclosporin
• clarithromycin (should not be taken in combination with simvastatin)
• danazol
• diltiazem
• erythromycin (should not be taken in combination with simvastatin)
• ezetimibe
• fibrates for lowering cholesterol, eg bezafibrate, gemfibrozil
• fusidic acid
• itraconazole (should not be taken in combination with simvastatin)
• ketoconazole (should not be taken in combination with simvastatin)
• nefazadone (should not be taken in combination with simvastatin)
• nicotinic acid or niacin
• protease inhibitors for HIV infection, eg nelfinavir (should not be taken in combination with simvastatin)
• telithromycin (should not be taken in combination with simvastatin)
• verapamil.

These medicines should be avoided where possible in people taking simvastatin. If treatment with the antifungals itraconazole or ketoconazole, or the antibiotics erythromycin, clarithromycin or telithromycin is unavoidable, therapy with simvastatin must be suspended during the course of treatment.

The anti-blood-clotting effect of anticoagulants such as warfarin may be increased by simvastatin. For this reason, if you are taking an anticoagulant your doctor may want to check your blood-clotting time when you start or stop treatment with simvastatin, and if your simvastatin dose is altered.

The following medicines may reduce the amount of simvastatin in your blood and could make it less effective:

• efavirenz
• rifampicin
• the herbal remedy St John's wort (Hypericum perforatum).

Other medicines containing the same active ingredient

Simvador

Zocor heart-pro

Simvastatin tablets are also available without a brand name, ie as the generic medicine.

Zocor (simvastatin)