Legal Classification of medication
POM and P
Simvastatin can be purchased over the counter from pharmacies (P) under the brand name Zocor Heart-Pro®; the strength of the tablet is limited to 10mg. Simvastatin can also be obtained on prescription (POM) and the strength dispensed will depend upon clinical need.
Simvastatin comes in four strengths, 10mg, 20mg, 40mg and 80mg and are available in tablet form.
Class of drug
Simvastatin is classed as a statin or a HMG-CoA reductase inhibitor.
Indications
Simvastatin is used to lower cholesterol and other lipids (fats) in the blood and may help prevent medical problems caused by cholesterol such as heart disease. It is also used in diabetic patients as a preventative that are at risk of forming thickened artery walls as a result of build up of cholesterol.
How does it work?
Statin drugs work by blocking a key enzyme in the production of cholesterol. Cholesterol is a natural product of the liver and in the right amounts does not pose a problem to the body. The body, however, sometimes produces too much cholesterol. Statin drugs block the enzyme linked to the liver's cholesterol production, HMG-CoA (3-hydroxy-3-methyglutaryl COA) reductase, thus inhibiting the liver's ability to produce LDL. This causes an increase in the number of the LDL receptors on the surface of liver cells, resulting in more cholesterol being removed from the bloodstream and a reduction in risk for high-cholesterol related diseases.
How is it taken?
Simvastatin is given by mouth in a usual dose of 10 to 20mg in the evening; an initial dose of 40mg may be used in patients who are at high risk of cardiovascular risk. The dose may be adjusted up to a maximum of 80mg once daily in the evening.
Pregnancy and breast feeding
Simvastatin is contra-indicated in pregnancy as there is a possibility that it reduces the levels of mevalonate which is used in the synthesis of fetal cholesterol. This is essential as cholesterol is the building blocks for all cells in developing fetus.
Women taking simvastatin should not breast feed their infants, as it is not known if simvastatin is excreted in breast milk and the potential side-effects it can cause to the infant.
Contra-indications
Active liver disease
Pregnancy
Breast feeding
Side-effects
The most common side-effects of therapy with simvastatin include:
Simvastatin can cause a rare but significant side-effect, causing unexplained muscle pain, tenderness, or weakness. If any of these side-effects are experienced the doctor must be contacted immediately..
Drugs or some foods used with simvastatin can increase the statin concentration in the blood and therefore further increase the potential risk of muscle associated side-effects. Grapefruit juice should be avoided for this particular reason in patients taking simvastatin as it increases the risk of muscle toxicity.
