Statins (also called HMG-CoA reductase inhibitors) block an enzyme called HMG-CoA reductase (3-hydroxy-3-methylglutaryl coenzyme A reductase) that is involved in the synthesis of mevalonate, a naturally occurring substance that is used by the body to make sterols, including cholesterol.
By inhibiting this enzyme, cholesterol and LDL-cholesterol production is decreased. Statins also increase the number of LDL receptors on liver cells, which enhances the uptake and breakdown of LDL-cholesterol. Most of the effects of statins, including the blocking of the HMG-CoA reductase enzyme) occurs in the liver.
Lowering cholesterol and other types of fats is important because research has shown that elevated levels of total cholesterol, LDL-cholesterol, triglycerides, and apolipoprotein B increase a person’s risk of developing heart disease or having a stroke.
What are statins used for?
Statins are used to:
- Lower high cholesterol (also known as hyperlipidemia or dyslipidemia). Statins are most effective at lowering LDL-cholesterol (this is commonly referred to as “bad” cholesterol)
- Reduce a person’s risk of having a heart attack or stroke or developing angina
- Reduce the risk of further heart disease in people with type 2 diabetes or coronary artery disease.
What are the differences between statins?
Statins differ in how effective they are at lowering total cholesterol, triglycerides, LDL-cholesterol, or increasing HDL-cholesterol; how likely they are to interact with other medications; and how safe they are for people with kidney disease.
Atorvastatin and simvastatin are the most effective at reducing LDL cholesterol levels. Atorvastatin and fluvastatin are preferred in people with kidney disease. Pravastatin and fluvastatin have a lower risk of drug interactions because they are not metabolized by cytochrome p450 3A4. Atorvastatin and fluvastatin are considered the most cost-effective statins.
Grapefruit juice increases levels of atorvastatin, lovastatin, and simvastatin, which may increase the risk of side effects. Grapefruit juice should be avoided with these statins.
Pitavastatin has a similar effectiveness to atorvastatin but reportedly produces greater increases in HDL-cholesterol that are sustained over the long-term. It is effective at low dosages and has minimal drug interactions.
|
Generic name |
Brand name examples |
|
atorvastatin |
Lipitor |
|
fluvastatin |
Lescol XL |
|
lovastatin |
Altoprev |
|
pitavastatin |
Livalo, Zypitamag |
|
pravastatin |
Generic |
|
rosuvastatin |
Crestor |
|
simvastatin |
Zocor |
Are statins safe?
Statins are generally safe when used at recommended dosages.
Serious muscle effects have been reported with statins, including rhabdomyolysis – this is the destruction of muscle cells. People aged older than 65, taking certain medications (for example cyclosporine, itraconazole, or HIV antivirals), who drink more than two alcoholic drinks per day, or with kidney disease, appear to be more at risk of serious side effects. Initial reports of muscle pain should be investigated by a doctor. Mild muscle pain is a common side effect of statins.
Rarely, statins may affect affect the liver or cause jaundice (a yellowing of the skin). This may require a reduction in dosage or discontinuation.
Statins may also affect some diabetes markers (such as HbA1c or fasting glucose), and may not be suitable in those with liver or kidney disease.
Some statins may not be suitable for some people including those with a recent history of stroke or transient ischemic attack (TIA). People with active liver disease or who are pregnant or breastfeeding should not take statins.
Rarely, statin use has been associated with memory loss, forgetfulness, amnesia, memory impairment, and confusion. These symptoms typically resolve with discontinuation.
Some statins, particularly those metabolized by CYP 3A4 (such as atorvastatin, pravastatin and simvastatin), can interact with several other drugs, such as clarithromycin, protease inhibitors, cyclosporine, gemfibrozil, oral contraceptives, and digoxin.
For a complete list of severe side effects, please refer to the individual drug monographs.
What are the side effects of statins?
The most common side effects reported with statins include:
- a headache
- belching or excessive gas
- constipation
- heartburn, indigestion, nausea or stomach discomfort
- hoarseness
- lower back or side pain
- muscle pain, tenderness, or weakness
- pain or tenderness around the eyes and cheekbones
- painful or difficult urination
- a stuffy or a runny nose
- sweating
- trouble sleeping.
For a complete list of side effects, please refer to the individual drug monographs.
