Simvastatin is a cholesterol-lowering drug belonging to the class of HMG-CoA reductase inhibitors, otherwise known as ‘statins’. Other statins include atorvastatin (Lipitor), fluvastatin (Lescol) and rosuvastatin (Crestor). Marketed under the trade name Zocor, Simvastatin is a synthetic derivative of a fermentation product of Aspergillus terreus. In 2005 Simvastatin was Merck & Co’s highest selling cholesterol drug in the world, recording sales of $4.3 billion.
Simvastatin is used in the treatment of dyslipidaemia and to prevent cardiovascular disease. It is generally only used when various other measures such as changes in diet and exercise have failed to improve cholesterol levels sufficiently.
The usual dosage of Simvastatin ranges from 5mg to 80mg and can reduce low-density lipoprotein (LDL) levels by up to 50%. At higher doses have been found to be too toxic and give only minimal benefit in lowering cholesterol levels.
Mechanism of Action
Like all statins, Simvastatin works by inhibiting 3-hydroxy-3-methylglutaryl (HMG-CoA) in the rate-limiting step of the metabolic pathway that leads to cholesterol production. In this way low-density lipoprotein (LDL) or ‘bad’ cholesterol is significantly reduced. Simvastatin also works to increase high density lipoprotein (HDL) or ‘good’ cholesterol which may slow conditions such as coronary artery disease.
There is also plenty of evidence to suggest that statins like Simvastatin reduce cardiovascular disease events and total mortality regardless of initial cholesterol level – otherwise known as pleitropic effects.
Simvastatin is contraindicated with pregnancy as it may lead to severe birth defects. It is also contraindicated with breast feeding and liver disease.