Statins work by blocking the action of a certain chemical (enzyme) which is needed to make cholesterol.
Statins are a group of medicines that are commonly used to reduce the level of cholesterol in the blood. They include atorvastatin, fluvastatin, pravastatin, rosuvastatin and simvastatin. They each have different brand names.
Who should take a statin?
Your doctor will advise if you should take a statin. A statin is usually advised if:
- You have a high cholesterol level (called hyperlipidaemia - read more about hyperlipidaemia and familial hypercholesterolaemia).
- You have an atheroma-related disease. This is a cardiovascular disease such as angina or peripheral arterial disease, or you have had a heart attack (myocardial infarction), stroke or transient ischaemic attack (TIA). A statin helps to reduce the risk of these conditions getting worse; or, it can delay the disease becoming worse.
- You have a high increased risk of developing an atheroma-related disease. For example, if you have diabetes, or other risk factors. Risk is measured as a percentage. Risk is considered to be high when your score is 10% or more (that is, a 1 in 10 chance or more of developing a cardiovascular disease within the 10 years that follow). See the separate leaflet called Cardiovascular Health Risk Assessment.
Note: a statin is just one factor in reducing your risk of developing cardiovascular diseases. See the separate leaflet called Cardiovascular Disease (Atheroma).
What happens when I take a statin?
You should have a blood test before starting treatment. This checks the level of cholesterol. It also checks if your liver is working properly. After starting treatment you should have a blood test within 1-3 months and again at 12 months. The blood test is to check that the liver has not been affected by the medication. The blood may also be checked to measure the cholesterol level to see how well the statin is working.
What is the target cholesterol level to aim for?
There is no actual target cholesterol blood level for people who do not already have cardiovascular disease. However, national guidelines recommend that people who have not been diagnosed with cardiovascular disease should be started on atorvastatin 20 mg a day. This is a 'high intensity' statin - the aim of giving high-intensity statins is to reduce your low-density lipoprotein (LDL) cholesterol by at least 40%.
If you do have a cardiovascular disease the aim, if possible, is to reduce total cholesterol (TChol) to less than 4.0 mmol/L and LDL cholesterol to less than 2.0 mmol/L. If the target is not reached at first, the dose may need to be increased or a different preparation used. National guidelines recommend that for people who have cardiovascular disease, the drug of choice is atorvastatin 80 mg a day.
Dr Sarah Jarvis, 23rd April 2019.
A study of over 165,000 patients taking statins has shown that about half of people taking statins did not reduce their LDL cholesterol by at least 40%. There may be several reasons for this, including people not taking their statin tablets regularly. However, people who were not prescribed 'high-intensity statins' (such as atorvastatin 20-80 mg a day) were less likely to reach this target.
Once age and starting cholesterol level were taken into account, people who did not reach this 40% target were 22% more likely to have a heart attack or stroke over the next six years.
If you are taking a statin, you may want to ask your GP what your pre-treatment and on-treatment levels of LDL cholesterol are. If your cholesterol has not reduced by at least 40% on treatment, you could discuss your medication with your doctor.
What are the possible side-effects or problems with statins?
Most people who take a statin have no side-effects, or only minor ones. Read the information leaflet that comes with your medicine. It will have a full list of possible side-effects. Possible statins' side-effects include headache, pins and needles, tummy (abdominal) pain, bloating, diarrhoea, feeling sick (nausea), and a rash.
Nov 2017 - Dr Hayley Willacy recently read a research paper in the British Medical Journal looking at the long-term use of statins - see Further Reading. They followed 3,234 people in the US Diabetes Prevention Program Outcomes Study for a period of 10 years. The most commonly prescribed statins were simvastatin (40%) and atorvastatin (37%). People who took a statin were 36% more likely to be diagnosed with type 2 diabetes, compared to those who had not been prescribed these medicines. The risk fell to 30% after taking other factors into account. Although those who were prescribed statins had slightly higher levels of blood glucose to start with, this still didn't explain their higher rates of diabetes. They found no link between the strength of the statin used and diabetes risk. Monitoring HbA1c levels may be useful in people who are prescribed a statin.
Points to remember
Tell your doctor if you have any unexpected muscle pains, tenderness, cramps or weakness. This is because a rare side-effect of statins is a severe form of muscle inflammation. Muscle pains may be more likely if you are also taking a medicine called amlodipine or diltiazem. Your doctor may need to adjust your dose of statin to reduce the risk.
You should not take a statin if you have active liver disease, if you are are pregnant or intend to be pregnant, or if you are breast-feeding. You should stop a statin if you develop liver disease.
Do not eat grapefruit or drink grapefruit juice if you are taking some statins. A chemical in grapefruit can increase the level of statin in the bloodstream, which can make side-effects from the statin more likely. This is only a problem with simvastatin, atorvastatin and lovastatin. Other statins, such as pravastatin, do not interact with grapefruit.
Various other medicines may interfere with statins. For example, some antibiotics and ciclosporin. The doses of either the statin or the other interacting medicine may need to be adjusted. So, if you are prescribed (or buy) another medicine, remind the doctor or pharmacist that you are on a statin in case an interaction is likely.
Tell a doctor if you develop chest symptoms such as unexplained shortness of breath or cough. This is because (in very rare cases) statins may cause a disease called interstitial lung disease.
Other medicines to reduce cholesterol and other lipids
Other medicines are sometimes used to lower cholesterol and other blood types of fats (lipids). These include:
- Bile acid sequestrants which include colestyramine, colesevelam and colestipol. They work by binding to bile acids which are passed into the gut from the liver and gallbladder. This stops bile acids being re-absorbed into the bloodstream, which has a knock-on effect of lowering cholesterol.
- Fibrates which include bezafibrate, ciprofibrate, fenofibrate, and gemfibrozil. One of these is used mainly if you have a high level of another type of lipid (triglyceride) with or without a high cholesterol level.
- Ezetimibe is sometimes used in certain situations in combination with a statin, or on its own. It prevents the absorption of cholesterol from the gut.
- Fish oils may help to reduce blood lipid levels. These occur naturally in oily fish such as mackerel. This is why at least 1-2 portions of oily fish per week are recommended in a healthy diet. Dietary supplements ('fish oil tablets', which contain omega-3 fatty acids) are also available. However, the value of fish oil supplements is controversial, as the evidence from research trials is unclear.
Can I buy a statin?
Statin medicines are available on prescription and funded by the NHS in the UK if you have a cardiovascular disease, or you have a high risk of developing a cardiovascular disease. A statin is not usually prescribed for people with lower levels of risk. Some statins are available to buy without a prescription. Some people choose to buy a statin to lower their cholesterol level.
Further reading and references
Lipid modification - cardiovascular risk assessment and the modification of blood lipids for the prevention of primary and secondary cardiovascular disease; NICE Clinical Guideline, July 2014 (updated September 2016)
de Souza RJ, Mente A, Maroleanu A, et al; Intake of saturated and trans unsaturated fatty acids and risk of all cause mortality, cardiovascular disease, and type 2 diabetes: systematic review and meta-analysis of observational studies. BMJ. 2015 Aug 11351:h3978. doi: 10.1136/bmj.h3978.
2016 ESC/EAS Guidelines for the Management of Dyslipidaemias; European Society of Cardiology (2016)
2016 European Guidelines on cardiovascular disease prevention in clinical practice; European Society of Cardiology (2016)
Linton MF, Yancey PG, Davies SS, et al; The Role of Lipids and Lipoproteins in Atherosclerosis
Crandall JP, Mather K, Rajpathak SN, et al; Statin use and risk of developing diabetes: results from the Diabetes Prevention Program. BMJ Open Diabetes Res Care. 2017 Oct 105(1):e000438. doi: 10.1136/bmjdrc-2017-000438. eCollection 2017.
Malhotra A, Redberg RF, Meier P; Saturated fat does not clog the arteries: coronary heart disease is a chronic inflammatory condition, the risk of which can be effectively reduced from healthy lifestyle interventions. Br J Sports Med. 2017 Aug51(15):1111-1112. doi: 10.1136/bjsports-2016-097285. Epub 2017 Apr 25.
Weng SF et al; Sub-optimal cholesterol response to initiation of statins and future risk of cardiovascular disease, BMJ, 2019