Statins (or HMG-CoA reductase inhibitors) are a Drug class of medications that lower cholesterol. They are prescribed typically to people who are at high risk of cardiovascular disease.
Low-density lipoprotein (LDL) carriers of cholesterol play a key role in the development of atherosclerosis and coronary heart disease via the mechanisms described by the lipid hypothesis. As lipid-lowering medications, statins are effective in lowering LDL cholesterol; they are widely used for primary prevention in people at high risk of cardiovascular disease, as well as in secondary prevention for those who have developed cardiovascular disease.
Side effects of statins include muscle pain, increased risk of diabetes, and abnormal blood levels of certain liver enzymes. Additionally, they have rare but severe adverse effects, particularly muscle damage, and very rarely rhabdomyolysis.
They act by inhibiting the enzyme HMG-CoA reductase, which plays a central role in the production of cholesterol. High cholesterol levels have been associated with cardiovascular disease.
There are various forms of statins, some of which include atorvastatin, fluvastatin, lovastatin, pitavastatin, pravastatin, rosuvastatin, and simvastatin.
Patient compliance with statin usage is problematic despite robust evidence of the benefits.
If there is an underlying history of cardiovascular disease, it has a significant impact on the effects of statin. This can be used to divide medication usage into broad categories of primary and secondary prevention.
Most evidence suggests that statins are also effective in preventing heart disease in those with high cholesterol but no history of heart disease. A 2013 Cochrane review found a decrease in risk of death and other poor outcomes without any evidence of harm. For every 138 people treated for 5 years, one fewer dies; for every 49 treated, one fewer has an episode of heart disease. A 2011 review reached similar conclusions, and a 2012 review found benefits in both women and men. A 2010 review concluded that treatment without history of cardiovascular disease reduces cardiovascular events in men but not women, and provides no mortality benefit in either sex. Two other meta-analyses published that year, one of which used data obtained exclusively from women, found no mortality benefit in primary prevention.
The National Institute for Health and Clinical Excellence (NICE) recommends statin treatment for adults with an estimated 10 year risk of developing cardiovascular disease that is greater than 10%. Guidelines by the American College of Cardiology and the American Heart Association recommend statin treatment for primary prevention of cardiovascular disease in adults with LDL cholesterol ≥ 190 mg/dL (4.9 mmol/L) or those with diabetes, age 40–75 with LDL-C 70–190 mg/dL (1.8–4.9 mmol/dL); or in those with a 10-year risk of developing heart attack or stroke of 7.5% or more. In this latter group, statin assignment was not automatic, but was recommended to occur only after a clinician-patient risk discussion with shared decision making where other risk factors and lifestyle are addressed, the potential for benefit from a statin is weighed against the potential for adverse effects or drug interactions and informed patient preference is elicited. Moreover, if a risk decision was uncertain, factors such as family history, coronary calcium score, ankle-brachial index, and an inflammation test (hs-CRP ≥ 2.0 mg/L) were suggested to inform the risk decision. Additional factors that could be used were an LDL-C ≥ 160 mg/dL (4.14 mmol/L) or a very high lifetime risk. However, critics such as Steven E. Nissen say that the AHA/ACC guidelines were not properly validated, overestimate the risk by at least 50%, and recommend statins for people who will not benefit, based on populations whose observed risk is lower than predicted by the guidelines. The European Society of Cardiology and the European Atherosclerosis Society recommend the use of statins for primary prevention, depending on baseline estimated cardiovascular score and LDL thresholds.
No studies have examined the effect of statins on cognition in patients with prior stroke. However, two large studies (HPS and PROSPER) that included people with vascular diseases reported that simvastatin and pravastatin did not impact cognition.
Statins have been studied for improving operative outcomes in cardiac and vascular surgery. Mortality and adverse cardiovascular events were reduced in statin groups.
Older adults who receive statin therapy at time of discharge from the hospital after an inpatient stay have been studied. People with cardiac ischemia not previously on statins at the time of admission have a lower risk of major cardiac adverse events and hospital readmission two years post-hospitalization.
In children, statins are effective at reducing cholesterol levels in those with familial hypercholesterolemia. Their long term safety is, however, unclear. Some recommend that if lifestyle changes are not enough statins should be started at 8 years old.
Asthma
Statins have been identified as having a possible adjunct role in the treatment of asthma through anti-inflammatory pathways. There is low quality evidence for the use of statins in treating asthma, however further research is required to determine the effectiveness and safety of this therapy in those with asthma.
The most important adverse side effects are muscle problems, an increased risk of diabetes mellitus, and increased liver enzymes in the blood due to liver damage. Over 5 years of treatment statins result in 75 cases of diabetes, 7.5 cases of bleeding stroke, and 5 cases of muscle damage per 10,000 people treated. This could be due to the statins inhibiting the enzyme (HMG-CoA reductase), which is necessary to make cholesterol, but also for other processes, such as CoQ10 production, which is important for muscle function and sugar regulation.
Other possible adverse effects include neuropathy, pancreas and liver dysfunction, and sexual dysfunction. The rate at which such events occur has been widely debated, in part because the risk/benefit ratio of statins in low-risk populations is highly dependent on the rate of adverse events. A Cochrane Library meta-analysis of statin clinical trials in primary prevention found no evidence of excess adverse events among those treated with statins compared to placebo. Another meta-analysis found a 39% increase in adverse events in statin treated people relative to those receiving placebo, but no increase in serious adverse events. The author of one study argued that adverse events are more common in clinical practice than in randomized clinical trials. A systematic review concluded that while clinical trial meta-analyses underestimate the rate of muscle pain associated with statin use, the rates of rhabdomyolysis are still "reassuringly low" and similar to those seen in clinical trials (about 1–2 per 10,000 person years). Another systematic review from the International Centre for Circulatory Health of the National Heart and Lung Institute in London concluded that only a small fraction of side effects reported by people on statins are actually attributable to the statin.
There are reports of reversible cognitive impairment with statins. The U.S. Food and Drug Administration (FDA) package insert on statins includes a warning about the potential for non-serious and reversible cognitive side effects with the medication (memory loss, confusion).
Muscle pain and other symptoms often cause patients to stop taking a statin. This is known as statin intolerance. A 2021 double-blind multiple crossover randomized controlled trial (RCT) in statin-intolerant patients found that adverse effects, including muscle pain, were similar between atorvastatin and placebo. A smaller double-blind RCT obtained similar results. The results of these studies help explain why statin symptom rates in observational studies are so much higher than in double-blind RCTs and support the notion that the difference results from the Nocebo; that the symptoms are caused by expectations of harm.
Media reporting on statins is often negative, and patient leaflets inform patients that rare but potentially serious muscle problems can occur during statin treatment. These create expectations of harm. Nocebo symptoms are real and bothersome and are a major barrier to treatment. Because of this, many people stop taking statins, which have been proven in numerous large-scale RCTs to reduce heart attacks, stroke, and deaths – as long as people continue to take them.
Serious muscle problems such as rhabdomyolysis (destruction of muscle cells) and statin-associated autoimmune myopathy occur in less than 0.1% of treated people. Rhabdomyolysis can in turn result in life-threatening kidney injury. The risk of statin-induced rhabdomyolysis increases with older age, use of interacting medications such as fibrates, and hypothyroidism. Coenzyme Q10 (ubiquinone) levels are decreased in statin use; CoQ10 supplements are sometimes used to treat statin-associated myopathy, though evidence of their efficacy is lacking . The gene SLCO1B1 ( Solute carrier organic anion transporter family member 1B1) codes for an organic anion-transporting polypeptide that is involved in the regulation of the absorption of statins. A common variation in this gene was found in 2008 to significantly increase the risk of myopathy.
Records exist of over 250,000 people treated from 1998 to 2001 with the statin drugs atorvastatin, cerivastatin, fluvastatin, lovastatin, pravastatin, and simvastatin. The incidence of rhabdomyolysis was 0.44 per 10,000 patients treated with statins other than cerivastatin. However, the risk was over 10-fold greater if cerivastatin was used, or if the standard statins (atorvastatin, fluvastatin, lovastatin, pravastatin, or simvastatin) were combined with a fibrate (fenofibrate or gemfibrozil) treatment. Cerivastatin was withdrawn by its manufacturer in 2001.
Some researchers have suggested hydrophilic statins, such as fluvastatin, rosuvastatin, and pravastatin, are less toxic than lipophilic statins, such as atorvastatin, lovastatin, and simvastatin, but other studies have not found a connection. Lovastatin induces the expression of gene atrogin-1, which is believed to be responsible in promoting muscle fiber damage. Tendon rupture does not appear to occur.
Consumption of grapefruit or grapefruit juice inhibits the metabolism of certain statins, and may have a similar effect. Katherine Zeratsky, R.D., L.D., Mayo clinic: article on interference between grapefruit and medication Accessed 1 May 2017 Furanocoumarins in grapefruit juice (i.e. bergamottin and dihydroxybergamottin) inhibit the cytochrome P450 enzyme CYP3A4, which is involved in the metabolism of most statins (however, it is a major inhibitor of only lovastatin, simvastatin, and to a lesser degree, atorvastatin) and some other medications (flavonoids (i.e. naringin) were thought to be responsible). This increases the levels of the statin, increasing the risk of dose-related adverse effects (including myopathy/rhabdomyolysis). The absolute prohibition of grapefruit juice consumption for users of some statins is controversial.
The U.S. Food and Drug Administration (FDA) notified healthcare professionals of updates to the prescribing information concerning interactions between protease inhibitors and certain statin drugs. Protease inhibitors and statins taken together may increase the blood levels of statins and increase the risk for muscle injury (myopathy). The most serious form of myopathy, rhabdomyolysis, can damage the kidneys and lead to kidney failure, which can be fatal.
In 2008, the JUPITER trial showed statins provided benefit in those who had no history of hyperlipidemia or heart disease, but only in those with elevated high-sensitivity C-reactive protein (hsCRP) levels, an indicator for inflammation. The study has been criticized due to perceived flaws in the study design, although Paul Ridker, lead investigator of the JUPITER trial, has responded to these criticisms at length.
As the target of statins, the HMG-CoA reductase, is highly similar between eukaryota and archaea, statins also act as antibiotics against archaea by inhibiting archaeal mevalonate biosynthesis. This has been shown in vivo and in vitro. Since patients with a constipation phenotype present with higher abundance of methanogenic archaea in the gut, the use of statins for management of irritable bowel syndrome has been proposed and may actually be one of the hidden benefits of statin use.
LDL-lowering potency varies between agents. Cerivastatin is the most potent (withdrawn from the market in August 2001 due to risk of serious rhabdomyolysis), followed by (in order of decreasing potency) rosuvastatin, atorvastatin, simvastatin, lovastatin, pravastatin, and fluvastatin. The relative potency of pitavastatin has not yet been fully established, but preliminary studies indicate a potency similar to rosuvastatin.
Some types of statins are naturally occurring, and can be found in such foods as oyster mushrooms and red yeast rice. Randomized controlled trials have found these foodstuffs to reduce circulating cholesterol, but the quality of the trials has been judged to be low.
Due to patent expiration, most of the block-buster branded statins have been generic since 2012, including atorvastatin, the largest-selling branded drug.
In 1971, Akira Endo, a Japanese biochemist working for the pharmaceutical company Daiichi Sankyo, began to investigate this problem. Research had already shown cholesterol is mostly manufactured by the body in the liver with the enzyme HMG-CoA reductase. Endo and his team reasoned that certain microorganisms may produce inhibitors of the enzyme to defend themselves against other organisms, as mevalonate is a precursor of many substances required by organisms for the maintenance of their cell walls or cytoskeleton (). The first agent they identified was mevastatin (ML-236B), a molecule produced by the fungus Penicillium citrinum.
A British group isolated the same compound from Penicillium brevicompactum, named it compactin, and published their report in 1976. The British group mentions antifungal properties, with no mention of HMG-CoA reductase inhibition. Mevastatin was never marketed, because of its adverse effects of tumors, muscle deterioration, and sometimes death in laboratory dogs. P. Roy Vagelos, chief scientist and later CEO of Merck & Co, was interested, and made several trips to Japan starting in 1975. By 1978, Merck had isolated lovastatin (mevinolin, MK803) from the fungus Aspergillus terreus, first marketed in 1987 as Mevacor.
In the 1990s, as a result of public campaigns, people in the United States became familiar with their cholesterol numbers and the difference between HDL and LDL cholesterol, and various pharmaceutical companies began producing their own statins, such as pravastatin (Pravachol), manufactured by Sankyo and Bristol-Myers Squibb. In April 1994, the results of a Merck-sponsored study, the Scandinavian Simvastatin Survival Study, were announced. Researchers tested simvastatin, later sold by Merck as Zocor, on 4,444 patients with high cholesterol and heart disease. After five years, the study concluded the patients saw a 35% reduction in their cholesterol, and their chances of dying of a heart attack were reduced by 42%. In 1995, Zocor and Mevacor both made Merck over .
Though he did not profit from his original discovery, Endo was awarded the 2006 Japan Prize, and the Lasker-DeBakey Clinical Medical Research Award in 2008, for his pioneering research. Endo was also inducted into the National Inventors Hall of Fame in Alexandria, Virginia in 2012. Michael S. Brown and Joseph Goldstein, who won the Nobel Prize for related work on cholesterol, said of Endo: "The millions of people whose lives will be extended through statin therapy owe it all to Akira Endo."
Several statins have been approved as in the United States:
Statins show a effect in reducing depressive symptoms post-myocardial infarction when used alongside standard Antidepressant, though they are not effective as standalone treatments.
A modelling study in the UK found that people aged 70 and older who take statins live longer in good health than those who do not, regardless of whether they have cardiovascular disease.
Medical uses
Primary prevention
Secondary prevention
Statin product offerings - comparative effectiveness
Women and children
Familial hypercholesterolemia
Contrast-induced nephropathy
Chronic kidney disease
Adverse effects
+ Choosing a statin for people with special considerationstable adapted from the following source, but check individual references for technical explanations
Kidney transplantation recipients taking ciclosporin Pravastatin or fluvastatin Drug interactions are possible, but studies have not shown that these statins increase exposure to ciclosporin. HIV-positive people taking protease inhibitors Atorvastatin, pravastatin or fluvastatin Negative interactions are more likely with other choices. Persons taking gemfibrozil, a non-statin lipid-lowering drug Atorvastatin Combining gemfibrozil and a statin increases risk of rhabdomyolysis and subsequently kidney failure Persons taking the anticoagulant warfarin Any statin The statin use may require that the warfarin dose be changed, as some statins increase the effect of warfarin.
Cognitive effects
Muscles
Diabetes
Cancer
Drug interactions
Osteoporosis and fractures
Mechanism of action
Inhibiting cholesterol synthesis
Increasing LDL uptake
Decreasing of specific protein prenylation
Other effects
Available forms
14–19 hours. 1–3 hours. 1–3 hours. 1–3 hours. 14–19 hours. 1–3 hours. + Statin equivalent dosages 5 mg 10 mg 20 mg 40 mg 80 mg – – 20 mg 40 mg if >45% Evening
History
misleading claims exaggerating the adverse effects of statins had received widespread media coverage, with a consequent negative impact to public health. Controversy over the effectiveness of statins in the medical literature was amplified in popular media in the early 2010s, leading an estimated 200,000 people in the UK to stop using statins over a six-month period to mid 2016, according to the authors of a study funded by the British Heart Foundation. They estimated that there could be up to 2,000 extra heart attacks or strokes over the following 10 years as a consequence. An unintended effect of the academic statin controversy has been the spread of scientifically questionable alternative therapies. Cardiologist [[Steven Nissen]] at [[Cleveland Clinic]] commented "We are losing the battle for the hearts and minds of our patients to Web sites..." promoting unproven medical therapies. [[Harriet Hall]] sees a spectrum of "statin denialism" ranging from [[pseudoscientific|Pseudoscience]] claims to the understatement of benefits and overstatement of side effects, all of which is contrary to the scientific evidence.
Research
External links
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