World Library  
Flag as Inappropriate
Email this Article


Article Id: WHEBN0000178197
Reproduction Date:

Title: Statin  
Author: World Heritage Encyclopedia
Language: English
Subject: Fibrate, Mevalonate pathway, Cerivastatin, Atorvastatin, Rosuvastatin
Collection: Statins
Publisher: World Heritage Encyclopedia


Drug class
Lovastatin, a compound isolated from Aspergillus terreus, was the first statin to be marketed.
Use High cholesterol
Biological target HMG-CoA reductase
ATC code C10AA
External links

Statins (or HMG-CoA reductase inhibitors) are a class of cholesterol lowering drugs that inhibit the enzyme HMG-CoA reductase which plays a central role in the production of cholesterol. High cholesterol levels have been associated with cardiovascular disease (CVD).[1] Statins have been found to reduce cardiovascular disease and mortality in those who are at high risk. The evidence is strong that statins are effective for treating CVD in the early stages of a disease (secondary prevention) and in those at elevated risk but without CVD (primary prevention).[2][3] Side effects of statins include muscle pain, increased risk of diabetes mellitus, and abnormalities in liver enzyme tests.[4] Additionally, they have rare but severe adverse effects, particularly muscle damage.[5]

As of 2010, a number of statins are on the market: atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Mevacor, Altocor), pitavastatin (Livalo), pravastatin (Pravachol), rosuvastatin (Crestor) and simvastatin (Zocor).[6] Several combination preparations of a statin and another agent, such as ezetimibe/simvastatin, are also available. In 2005 sales were estimated at $18.7 billion in the United States.[7] The best-selling statin is atorvastatin, which in 2003 became the best-selling pharmaceutical in history.[8] The manufacturer Pfizer reported sales of US$12.4 billion in 2008.[9] Due to patent expirations, several statins are now available as less expensive generics.[10][11]


  • Medical uses 1
    • Primary prevention 1.1
    • Secondary prevention 1.2
    • Comparative effectiveness 1.3
    • Children 1.4
    • Prevention of contrast induced nephropathy 1.5
  • Adverse effects 2
    • Cognitive effects 2.1
    • Muscles 2.2
    • Diabetes 2.3
    • Cancer 2.4
    • Drug interactions 2.5
  • Mechanism of action 3
    • Inhibiting cholesterol synthesis 3.1
    • Increasing LDL uptake 3.2
    • Decreasing of specific protein prenylation 3.3
    • Other effects 3.4
  • Available forms 4
  • History 5
  • Research 6
  • References 7
  • External links 8

Medical uses

Clinical practice guidelines generally recommend people to try "lifestyle modification", including a cholesterol-lowering diet and physical exercise, before statin use. Statins or other pharmacologic agents may be recommended for those who do not meet their lipid-lowering goals through diet and lifestyle changes.[12][13] Statins appear to work equally well in males and females.[14]

Primary prevention

Most evidence suggests that statins are 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.[3] For every 138 people treated for 5 years one fewer dies and for every 49 treated one fewer has an episode of heart disease.[7] A 2011 review reached similar conclusions.[15] And a 2012 review found benefits in both women and men.[16] A 2010 review concluded that treating people with no history of cardiovascular disease reduces cardiovascular events in men but not women, and provides no mortality benefit in either sex.[17] Two other meta analyses published that year, one of which used data obtained exclusively from women, found no mortality benefit in primary prevention.[18][19]

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%.[20] 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.[21] 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 patients who will not benefit, based on populations whose observed risk is lower than predicted by the guidelines.[22] 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.[23]

Secondary prevention

Statins are effective in decreasing mortality in people with pre-existing CVD. They are also currently advocated for use in patients at high risk of developing heart disease.[24] On average, statins can lower LDL cholesterol by 1.8 mmol/l (70 mg/dl), which translates into an estimated 60% decrease in the number of cardiac events (heart attack, sudden cardiac death) and a 17% reduced risk of stroke after long-term treatment.[25] They have less effect than the fibrates or niacin in reducing triglycerides and raising HDL-cholesterol ("good cholesterol").

Statins have been studied for improving operative outcomes in cardiac and vascular surgery.[26] Mortality and adverse cardiovascular events were reduced in statin groups.[27]

Comparative effectiveness

While no direct comparison exists, all statins appear effective regardless of potency or degree of cholesterol reduction.[28] There do appear to be some differences between them, with simvastatin and pravastatin appearing superior in terms of side-effects.[4]

A comparison of atorvastatin, pravastatin and simvastatin, based on their effectiveness against placebos, found, at commonly prescribed doses, no statistically significant differences among agents in reducing cardiovascular morbidity and mortality.[29]


In children statins are effective at reducing cholesterol levels in those with familial hypercholesterolemia.[30] Their long term safety is, however, unclear.[30][31] Some recommend that if lifestyle changes are not enough statins should be started at 8 years old.[32]

Prevention of contrast induced nephropathy

A recent meta-analysis of randomized controlled trials found that statins could reduce the risk of contrast-induced nephropathy by 53% in people undergoing coronary angiography/percutaneous interventions. The effect was found to be stronger among those with preexisting kidney dysfunction or diabetes mellitus.[33]

Adverse effects

Choosing a statin for people with special considerations[34]
Condition Commonly recommended statins explanation
kidney transplantation recipients taking ciclosporin Pravastatin or Fluvastatin Drug interactions are possible, but studies have not shown that these statins increase exposure to ciclosporin.[35]
HIV-positive people taking protease inhibitors Atorvastatin, Pravastatin or Fluvastatin Negative interactions are more likely with other choices[36]
persons taking gemfibrozil, a non-statin cholesterol-lowering drug Atorvastatin Combining gemfibrozil and a statin increases risk of rhabdomyolysis and subsequently kidney failure[37][38]
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.[39]

The most important adverse side effects are increased concentrations of liver enzymes, muscle problems, and an increased risk of diabetes.[40][41] Other possible adverse effects include cognitive loss, neuropathy, pancreatic and hepatic dysfunction, and sexual dysfunction.[42] 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.[43][44][45] A Cochrane group meta analysis of statin clinical trials in primary prevention found no evidence of excess adverse events among those treated with statins compared to placebo.[46] 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.[47] The author of one study argued that adverse events are more common in clinical practice than in randomized clinical trials.[42] A systematic review by the Canadian Working Group Consensus Conference that considered published meta analyses of clinical trials, spontaneous adverse event reports to the FDA, and published cohort studies 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 patient years).[48] A systematic review co-authored by Ben Goldacre concluded that only a small fraction of side effects reported by patients on statins are actually attributable to the statin.[49]

Cognitive effects

There are anecdotal reports of cognitive decline with statins.[50] A systematic review by the Canadian Working Group Consensus Conference concluded that the available evidence "is not strongly supportive of a major adverse effect of statins".[51] Another meta-analysis reported concluded that there is moderate quality evidence of no increase in dementia, mild cognitive impairment or cognitive performance scores, although the strength of the evidence is limited, particularly for high doses.[52] In 2012, in recognition of an increase in anecdotal reports and increasing concerns over the relationship between statins and memory loss (including reports of transient global amnesia), forgetfulness and confusion, the FDA added to its required labeling on statin drugs a warning about possible cognitive impacts.[53] The effects are described as rare, non-serious, and reversible upon cessation of treatment.[54]


In observational studies 10-15% of people who take statins experience muscle problems; in most cases these consist of muscle pain.[5] These rates, which are much higher than those seen in randomized clinical trials[48] have been the topic of extensive debate and discussion.

Rare reactions include

External links

  1. ^ Lewington S, Whitlock G, Clarke R, Sherliker P, Emberson J, Halsey J, Qizilbash N, Peto R, Collins R (December 2007). "Blood cholesterol and vascular mortality by age, sex, and blood pressure: a meta-analysis of individual data from 61 prospective studies with 55,000 vascular deaths". Lancet 370 (9602): 1829–39.  
  2. ^ "Lipid Modification - National Library of Medicine - PubMed Health". 
  3. ^ a b Taylor F, Huffman MD, Macedo AF, Moore TH, Burke M,  
  4. ^ a b Naci H, Brugts J, Ades T (2013). "Comparative tolerability and harms of individual statins: a study-level network meta-analysis of 246 955 participants from 135 randomized, controlled trials". Circ Cardiovasc Qual Outcomes 6 (4): 390–9.  
  5. ^ a b Abd TT, Jacobson TA (May 2011). "Statin-induced myopathy: a review and update.". Expert opinion on drug safety 10 (3): 373–87.  
  6. ^ Sweetman, Sean C., ed. (2009). "Cardiovascular drugs". Martindale: the complete drug reference (36th ed.). London: Pharmaceutical Press. pp. 1155–434.  
  7. ^ a b Taylor, FC; Huffman, M; Ebrahim, S (11 December 2013). "Statin therapy for primary prevention of cardiovascular disease.". JAMA 310 (22): 2451–2.  
  8. ^ a b c d e Simons, John. "The $10 billion pill", Fortune magazine, January 20, 2003.
  9. ^ "Doing Things Differently", Pfizer 2008 Annual Review, April 23, 2009, p. 15.
  10. ^ "". 
  11. ^ "". 
  12. ^ National Cholesterol Education Program (2001). Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III): Executive Summary. Bethesda, MD: National Institutes of Health. National Heart, Lung, and Blood Institute. p. 40. NIH Publication No. 01-3670. 
  13. ^ National Collaborating Centre for Primary Care (2010). NICE clinical guideline 67: Lipid modification (PDF). London: National Institute for Health and Clinical Excellence. p. 38. 
  14. ^ Cholesterol Treatment Trialists' (CTT), Collaboration; Fulcher, J; O'Connell, R; Voysey, M; Emberson, J; Blackwell, L; Mihaylova, B; Simes, J; Collins, R; Kirby, A; Colhoun, H; Braunwald, E; La Rosa, J; Pedersen, TR; Tonkin, A; Davis, B; Sleight, P; Franzosi, MG; Baigent, C; Keech, A (11 April 2015). "Efficacy and safety of LDL-lowering therapy among men and women: meta-analysis of individual data from 174,000 participants in 27 randomised trials.". Lancet (London, England) 385 (9976): 1397–405.  
  15. ^ Tonelli M, Lloyd A, Clement F, Conly J, Husereau D, Hemmelgarn B, Klarenbach S, McAlister FA, Wiebe N, Manns B (2011). "Efficacy of statins for primary prevention in people at low cardiovascular risk: a meta-analysis". CMAJ 183 (16): E1189–202.  
  16. ^ Kostis WJ, Cheng JQ, Dobrzynski JM, Cabrera J, Kostis JB (2012). "Meta-analysis of statin effects in women versus men". J. Am. Coll. Cardiol. 59 (6): 572–82.  
  17. ^ Petretta M, Costanzo P, Perrone-Filardi P, Chiariello M (2010). "Impact of gender in primary prevention of coronary heart disease with statin therapy: a meta-analysis". Int. J. Cardiol. 138 (1): 25–31.  
  18. ^ Ray KK, Seshasai SR, Erqou S, Sever P, Jukema JW, Ford I, Sattar N (2010). "Statins and all-cause mortality in high-risk primary prevention: a meta-analysis of 11 randomized controlled trials involving 65,229 participants". Arch. Intern. Med. 170 (12): 1024–31.  
  19. ^ Bukkapatnam RN, Gabler NB, Lewis WR (2010). "Statins for primary prevention of cardiovascular mortality in women: a systematic review and meta-analysis". Prev Cardiol 13 (2): 84–90.  
  20. ^ "". 
  21. ^ Stone, NJ; Robinson, J;  
  22. ^ Steven E. Nissen (October 6, 2014). "Prevention Guidelines: Bad Process, Bad Outcome". JAMA Intern Med. 174: 1972.  
  23. ^ Grupo de Trabajo de la Sociedad Europea de Cardiología (ESC) y de la Sociedad Europea de Aterosclerosis, (EAS); Reiner, Z; Catapano, AL; De Backer, G; Graham, I; Taskinen, MR; Wiklund, O; Agewall, S; Alegría, E; John Chapman, M; Durrington, P; Erdine, S; Halcox, J; Hobbs, R; Kjekshus, J; Perrone Filardi, P; Riccardi, G; Storey, RF; Wood, D (Dec 2011). "ESC/EAS Guidelines for the management of dyslipidaemias." (PDF). Revista espanola de cardiologia (English ed.) 64 (12): 1168.  
  24. ^  
  25. ^ Law MR, Wald NJ, Rudnicka AR (June 2003). "Quantifying effect of statins on low density lipoprotein cholesterol, ischaemic heart disease, and stroke: systematic review and meta-analysis". BMJ 326 (7404): 1423.  
  26. ^ de Waal BA, Buise MP, van Zundert AA (January 2015). "Perioperative statin therapy in patients at high risk for cardiovascular morbidity undergoing surgery: a review". Br J Anaesth 114 (1): 44–52.  
  27. ^ Antoniou GA, Hajibandeh S, Hajibandeh S, Vallabhaneni SR, Brennan JA, Torella F (December 2014). "Meta-analysis of the effects of statins on perioperative outcomes in vascular and endovascular surgery". J Vasc Surg. S0741-5214 (14): 01903–X.  
  28. ^ Tonelli M, Lloyd A, Clement F, Conly J, Husereau D, Hemmelgarn B, Klarenbach S, McAlister FA, Wiebe N, Manns B (Nov 8, 2011). "Efficacy of statins for primary prevention in people at low cardiovascular risk: a meta-analysis". CMAJ : Canadian Medical Association 183 (16): E1189–E1202.  
  29. ^ Zhou Z, Rahme E, Pilote L (2006). "Are statins created equal? Evidence from randomized trials of pravastatin, simvastatin, and atorvastatin for cardiovascular disease prevention". Am. Heart J. 151 (2): 273–81.  
  30. ^ a b Vuorio, A; Kuoppala, J; Kovanen, PT; Humphries, SE; Strandberg, T; Tonstad, S; Gylling, H (Jul 7, 2010). "Statins for children with familial hypercholesterolemia.". The Cochrane database of systematic reviews (7): CD006401.  
  31. ^ Lamaida, N; Capuano, E; Pinto, L; Capuano, E; Capuano, R; Capuano, V (Sep 2013). "The safety of statins in children.". Acta paediatrica (Oslo, Norway : 1992) 102 (9): 857–62.  
  32. ^ Braamskamp, MJ; Wijburg, FA; Wiegman, A (Apr 16, 2012). "Drug therapy of hypercholesterolaemia in children and adolescents.". Drugs 72 (6): 759–72.  
  33. ^ Liu, YH; Liu, Y; Duan, CY (September 2014). "Statins for the Prevention of Contrast-Induced Nephropathy After Coronary Angiography/Percutaneous Interventions: A Meta-analysis of Randomized Controlled Trials.". J Cardiovasc Pharmacol Ther 20: 181–192.  
  34. ^ table adapted from the following source, but check individual references for technical explanations
  35. ^ Asberg A (2003). "Interactions between cyclosporin and lipid-lowering drugs: Implications for organ transplant recipients". Drugs 63 (4): 367–378.  
  36. ^  
  37. ^ Bellosta S, Paoletti R, Corsini A (2004). "Safety of Statins: Focus on Clinical Pharmacokinetics and Drug Interactions". Circulation 109 (23_suppl_1): III–I50.  
  38. ^ Omar MA, Wilson JP (2002). "FDA Adverse Event Reports on Statin-Associated Rhabdomyolysis". The Annals of Pharmacotherapy 36 (2): 288–295.  
  39. ^ Armitage J (2007). "The safety of statins in clinical practice". The Lancet 370 (9601): 1781–1790.  
  40. ^ Naci H, Brugts J, Ades T (July 2013). "Comparative tolerability and harms of individual statins: a study-level network meta-analysis of 246 955 participants from 135 randomized, controlled trials". Circ Cardiovasc Qual Outcomes 6 (4): 390–9.  
  41. ^ Bellosta, S; Corsini, A (2012). "Statin drug interactions and related adverse reactions". Expert Opin Drug Saf 11 (6): 933–46.  
  42. ^ a b Golomb BA, Evans MA (2008). "Statin Adverse Effects: A Review of the Literature and Evidence for a Mitochondrial Mechanism". Am J Cardiovasc Drugs 8 (6): 373–418.  
  43. ^ Kmietowicz Z (2014). "New analysis fuels debate on merits of prescribing statins to low risk people". BMJ 348: g2370.  
  44. ^ Wise J (2014). "Open letter raises concerns about NICE guidance on statins". BMJ 348: g3937.  
  45. ^ Gøtzsche PC (2014). "Muscular adverse effects are common with statins". BMJ 348: g3724.  
  46. ^ Taylor F, Huffman MD, Macedo AF, et al. (2013). "Statins for the primary prevention of cardiovascular disease". Cochrane Database Syst Rev 1: CD004816.  
  47. ^ Silva MA, Swanson AC, Gandhi PJ, Tataronis GR (January 2006). "Statin-related adverse events: a meta-analysis". Clin Ther 28 (1): 26–35.  
  48. ^ a b Mancini GB, Baker S, Bergeron J, et al. (2011). "Diagnosis, prevention, and management of statin adverse effects and intolerance: proceedings of a Canadian Working Group Consensus Conference". Can J Cardiol 27 (5): 635–62.  
  49. ^ Finegold JA, Manisty CH, Goldacre B, Barron AJ, Francis DP (April 2014). "What proportion of symptomatic side effects in patients taking statins are genuinely caused by the drug? Systematic review of randomized placebo-controlled trials to aid individual patient choice". Eur J Prev Cardiol 21 (4): 464–74.  
  50. ^ Jonathan McDonagh (October 27, 2014). "Statin-Related Cognitive Impairment in the Real World: You’ll Live Longer, but You Might Not Like It". JAMA Intern Med. 174: 1889.  
  51. ^ Mancini GB, Tashakkor AY, Baker S, et al. (December 2013). "Diagnosis, prevention, and management of statin adverse effects and intolerance: Canadian Working Group Consensus update". Can J Cardiol 29 (12): 1553–68.  
  52. ^ Richardson K, Schoen M, French B, Umscheid CA, Mitchell MD, Arnold SE, Heidenreich PA, Rader DJ, deGoma EM. (Nov 19, 2013). "Statins and cognitive function: a systematic review.". Ann Intern Med. 159 (10): 688–97.  
  53. ^ Url =
  54. ^ "" (PDF). 
  55. ^ Rull, Gurvinder; Henderson, Roger (2015-01-20). "Rhabdomyolysis and Other Causes of Myoglobinuria". Retrieved 2015-05-06. 
  56. ^ Ghirlanda G, Oradei A, Manto A, Lippa S, Uccioli L, Caputo S, Greco AV, Littarru GP (1993). "Evidence of plasma CoQ10-lowering effect by HMG-CoA reductase inhibitors: a double-blind, placebo-controlled study". J Clin Pharmacol 33 (3): 226–9.  
  57. ^ Marcoff L, Thompson PD (2007). "The role of coenzyme Q10 in statin-associated myopathy: a systematic review". J. Am. Coll. Cardiol. 49 (23): 2231–7.  
  58. ^ Link E, Parish S, Armitage J, Bowman L, Heath S, Matsuda F, Gut I, Lathrop M, Collins R (2008). "SLCO1B1 Variants and Statin-Induced Myopathy – A Genomewide Study". NEJM 359 (8): 789–799.  
  59. ^ a b Graham DJ, Staffa JA, Shatin D, Andrade SE, Schech SD, La Grenade L, Gurwitz JH, Chan KA, Goodman MJ, Platt R (2004). "Incidence of hospitalized rhabdomyolysis in patients treated with lipid-lowering drugs" (PDF). JAMA 292 (21): 2585–90.  
  60. ^ a b Hanai J, Cao P, Tanksale P, Imamura S, Koshimizu E, Zhao J, Kishi S, Yamashita M, Phillips PS, Sukhatme VP, Lecker SH (2007). "The muscle-specific ubiquitin ligase atrogin-1/MAFbx mediates statin-induced muscle toxicity". J. Clin. Invest. 117 (12): 3940–51.  
  61. ^ Sattar N, Preiss D, Murray HM, Welsh P, Buckley BM, de Craen AJ, Seshasai SR, McMurray JJ, Freeman DJ, Jukema JW, Macfarlane PW, Packard CJ, Stott DJ, Westendorp RG, Shepherd J, Davis BR, Pressel SL, Marchioli R, Marfisi RM, Maggioni AP, Tavazzi L, Tognoni G, Kjekshus J, Pedersen TR, Cook TJ, Gotto AM, Clearfield MB, Downs JR, Nakamura H, Ohashi Y, Mizuno K, Ray KK, Ford I (2010). "Statins and risk of incident diabetes: a collaborative meta-analysis of randomised statin trials". Lancet 375 (9716): 735–42.  
  62. ^ Preiss D, Seshasai SR, Welsh P, Murphy SA, Ho JE, Waters DD, DeMicco DA, Barter P, Cannon CP, Sabatine MS, Braunwald E, Kastelein JJ, de Lemos JA, Blazing MA, Pedersen TR, Tikkanen MJ, Sattar N, Ray KK (2011). "Risk of incident diabetes with intensive-dose compared with moderate-dose statin therapy: a meta-analysis". JAMA 305 (24): 2556–64.  
  63. ^ Jukema JW, Cannon CP, de Craen AJ, Westendorp RG, Trompet S (Sep 4, 2012). "The controversies of statin therapy: weighing the evidence.". Journal of the American College of Cardiology 60 (10): 875–81.  
  64. ^ Rutishauser J (Nov 21, 2011). "Statins in clinical medicine.". Swiss medical weekly 141: w13310.  
  65. ^ Alsheikh-Ali AA, Maddukuri PV, Han H, Karas RH (2007). "Effect of the Magnitude of Lipid Lowering on Risk of Elevated Liver Enzymes, Rhabdomyolysis, and Cancer: Insights from Large Randomized Statin Trials". Journal of the American College of Cardiology 50 (5): 409–418.  
  66. ^ Dale KM, Coleman CI, Henyan NN, Kluger J, White CM (2006). "Statins and cancer risk: a meta-analysis". JAMA 295 (1): 74–80.  
  67. ^ Alsheikh-Ali AA, Karas RH (March 2009). "The relationship of statins to rhabdomyolysis, malignancy, and hepatic toxicity: evidence from clinical trials.". Current atherosclerosis reports 11 (2): 100–4.  
  68. ^ Singh S, Singh AG, Singh PP, Murad MH, Iyer PG (June 2013). "Statins are associated with reduced risk of esophageal cancer, particularly in patients with Barrett's esophagus: a systematic review and meta-analysis.". Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association 11 (6): 620–9.  
  69. ^ Liu Y, Tang W, Wang J, Xie L, Li T, He Y, Deng Y, Peng Q, Li S, Qin X (Nov 22, 2013). "Association between statin use and colorectal cancer risk: a meta-analysis of 42 studies.". Cancer causes & control : CCC 25 (2): 237–49.  
  70. ^ Wu XD, Zeng K, Xue FQ, Chen JH, Chen YQ (October 2013). "Statins are associated with reduced risk of gastric cancer: a meta-analysis.". European journal of clinical pharmacology 69 (10): 1855–60.  
  71. ^ Singh PP, Singh S (July 2013). "Statins are associated with reduced risk of gastric cancer: a systematic review and meta-analysis.". Annals of oncology : official journal of the European Society for Medical Oncology / ESMO 24 (7): 1721–30.  
  72. ^ Pradelli D, Soranna D, Scotti L, Zambon A, Catapano A, Mancia G, La Vecchia C, Corrao G (May 2013). "Statins and primary liver cancer: a meta-analysis of observational studies.". European journal of cancer prevention : the official journal of the European Cancer Prevention Organisation (ECP) 22 (3): 229–34.  
  73. ^ Zhang Y, Zang T (2013). "Association between statin usage and prostate cancer prevention: a refined meta-analysis based on literature from the years 2005–2010.". Urologia internationalis 90 (3): 259–62.  
  74. ^ Bansal D, Undela K, D'Cruz S, Schifano F (2012). "Statin use and risk of prostate cancer: a meta-analysis of observational studies.". PLoS ONE 7 (10): e46691.  
  75. ^ Tan M, Song X, Zhang G, Peng A, Li X, Li M, Liu Y, Wang C (2013). "Statins and the risk of lung cancer: a meta-analysis.". PLoS ONE 8 (2): e57349.  
  76. ^ Zhang XL, Liu M, Qian J, Zheng JH, Zhang XP, Guo CC, Geng J, Peng B, Che JP, Wu Y (Jul 23, 2013). "Statin use and risk of kidney cancer: a meta-analysis of observational studies and randomized trials.". British Journal of Clinical Pharmacology 77 (3): 458–465.  
  77. ^ Undela K, Srikanth V, Bansal D (August 2012). "Statin use and risk of breast cancer: a meta-analysis of observational studies.". Breast cancer research and treatment 135 (1): 261–9.  
  78. ^ Cui X, Xie Y, Chen M, Li J, Liao X, Shen J, Shi M, Li W, Zheng H, Jiang B (July 2012). "Statin use and risk of pancreatic cancer: a meta-analysis.". Cancer causes & control : CCC 23 (7): 1099–111.  
  79. ^ Zhang XL, Geng J, Zhang XP, Peng B, Che JP, Yan Y, Wang GC, Xia SQ, Wu Y, Zheng JH (April 2013). "Statin use and risk of bladder cancer: a meta-analysis.". Cancer causes & control : CCC 24 (4): 769–76.  
  80. ^ Mayo clinic: article on interference between grapefruit and medication
  81. ^ Kane GC, Lipsky JJ (2000). "Drug-grapefruit juice interactions". Mayo Clin. Proc. 75 (9): 933–42.  
  82. ^ Reamy BV, Stephens MB (July 2007). "The grapefruit-drug interaction debate: role of statins". Am Fam Physician 76 (2): 190, 192; author reply 192.  
  83. ^ FDA Website Statins and HIV or Hepatitis C Drugs: Drug Safety Communication – Interaction Increases Risk of Muscle Injury
  84. ^ Istvan ES, Deisenhofer J (2001). "Structural mechanism for statin inhibition of HMG-CoA reductase". Science 292 (5519): 1160–4.  
  85. ^ a b Endo A (1 November 1992). "The discovery and development of HMG-CoA reductase inhibitors" (PDF). J. Lipid Res. 33 (11): 1569–82.  
  86. ^ Miettinen TA (March 1982). "Diurnal variation of cholesterol precursors squalene and methyl sterols in human plasma lipoproteins". Journal of Lipid Research 23 (3): 466–73.  
  87. ^ Saito Y, Yoshida S, Nakaya N, Hata Y, Goto Y (Jul–Aug 1991). "Comparison between morning and evening doses of simvastatin in hyperlipidemic subjects. A double-blind comparative study". Arterioscler Thromb 11 (4): 816–26.  
  88. ^ Wallace A, Chinn D, Rubin G (4 October 2003). "Taking simvastatin in the morning compared with in the evening: randomised controlled trial". British Medical Journal 327 (7418): 788.  
  89. ^ Cilla DD, Gibson DM, Whitfield LR, Sedman AJ (July 1996). "Pharmacodynamic effects and pharmacokinetics of atorvastatin after administration to normocholesterolemic subjects in the morning and evening". Journal of Clinical Pharmacology 36 (7): 604–9.  
  90. ^ Ma PT, Gil G, Südhof TC, Bilheimer DW, Goldstein JL, Brown MS (1986). "Mevinolin, an inhibitor of cholesterol synthesis, induces mRNA for low density lipoprotein receptor in livers of hamsters and rabbits" (PDF). Proc. Natl. Acad. Sci. U.S.A. 83 (21): 8370–4.  
  91. ^ Laufs U , Custodis F, Böhm M (2006). "HMGCoA reductase inhibitors in chronic heart failure: potential mechanisms of benefit and risk". Drugs 66 (2): 145–154.  
  92. ^ Greenwood J, Steinman L, Zamvil SS (May 2006). "Statin therapy and autoimmune disease: from protein prenylation to immunomodulation". Nat Rev Immunol 6 (5): 358–70.  
  93. ^ Lahera V, Goicoechea M, de Vinuesa SG, Miana M, de las Heras N, Cachofeiro V, Luño J (2007). "Endothelial dysfunction, oxidative stress and inflammation in atherosclerosis: beneficial effects of statins". Curr Med Chem 14 (2): 243–8.  
  94. ^ Blum A1, Shamburek R (April 2009). "The pleiotropic effects of statins on endothelial function, vascular inflammation, immunomodulation and thrombogenesis". Atherosclerosis 203 (2): 325–30.  
  95. ^ Porter KE1, Turner NA (2011). "Statins and myocardial remodelling: cell and molecular pathways". Expert Rev Mol Med 13 (e22).  
  96. ^ Sawada N , Liao JK (2014). "Rho/Rho associated coiled coil forming kinase pathway as therapeutic targets for statins in atherosclerosis". Antioxid Redox Signal 20 (8): 1251–67.  
  97. ^ "Questions Remain in Cholesterol Research". MedPageToday. 15 August 2014. 
  98. ^ Thurnher M, Nussbaumer O, Gruenbacher G (Jul 2012). "Novel aspects of mevalonate pathway inhibitors as antitumor agents". Clin Cancer Res 18 (13): 3524–31.  
  99. ^ Norata GD1, Tibolla G2, Catapano AL3. (Oct 2014). "Statins and skeletal muscles toxicity: from clinical trials to everyday practice.". Pharmacol Res 88: 107–13.  
  100. ^ Kowluru A (Jan 2008). "Protein prenylation in glucose-induced insulin secretion from the pancreatic islet beta cell: a perspective". J Cell Mol Med 12 (1): 164–73.  
  101. ^ Nissen SE, Nicholls SJ, Sipahi I, Libby P, Raichlen JS, Ballantyne CM, Davignon J, Erbel R, Fruchart JC, Tardif JC, Schoenhagen P, Crowe T, Cain V, Wolski K, Goormastic M, Tuzcu EM (2006). "Effect of very high-intensity statin therapy on regression of coronary atherosclerosis: the ASTEROID trial". JAMA 295 (13): 1556–65.  
  102. ^ Furberg CD (19 January 1999). "Natural Statins and Stroke Risk". Circulation 99 (2): 185–188.  
  103. ^ Ridker PM, Danielson E, Fonseca FA, Genest J, Gotto AM, Kastelein JJ, Koenig W, Libby P, Lorenzatti AJ, MacFadyen JG, Nordestgaard BG, Shepherd J, Willerson JT, Glynn RJ (2008). "Rosuvastatin to prevent vascular events in men and women with elevated C-reactive protein" (PDF). NEJM 359 (21): 2195–207.  
  104. ^ Kones R (2010). "Rosuvastatin, inflammation, C-reactive protein, JUPITER, and primary prevention of cardiovascular disease--a perspective". Drug Des Devel Ther 4: 383–413.  
  105. ^ Ferdinand KC (February 2011). "Are cardiovascular benefits in statin lipid effects dependent on baseline lipid levels?". Curr Atheroscler Rep 13 (1): 64–72.  
  106. ^ Devaraj S, Siegel D, Jialal I (February 2011). "Statin therapy in metabolic syndrome and hypertension post-JUPITER: what is the value of CRP?". Curr Atheroscler Rep 13 (1): 31–42.  
  107. ^ Safety of Statins: Focus on Clinical Pharmacokinetics and Drug Interactions" Circulation 2004:109:III-50-IIIi-57
  108. ^ "Metabolism of cerivastatin by human liver microsomes in vitro. Characterization of primary metabolic pathways and of cytochrome P450 isozymes involved". Drug Metab Dispos 25 (3): 321–31. Mar 1997. 
  109. ^ "Comparison of Cytochrome P-450-Dependent Metabolism and Drug Interactions of the 3-Hydroxy-3-methylglutaryl-CoA Reductase Inhibitors Lovastatin and Pravastatin in the Liver". DMD 27 (2): 173–179. 1999. 
  110. ^ Shepherd J, Hunninghake DB, Barter P, McKenney JM, Hutchinson HG (2003). "Guidelines for lowering lipids to reduce coronary artery disease risk: a comparison of rosuvastatin with atorvastatin, pravastatin, and simvastatin for achieving lipid-lowering goals". Am. J. Cardiol. 91 (5A): 11C–17C; discussion 17C–19C.  
  111. ^ Liu J, Zhang J, Shi Y, Grimsgaard S, Alraek T, Fønnebø V (2006). "Chinese red yeast rice (Monascus purpureus) for primary hyperlipidemia: a meta-analysis of randomized controlled trials". Chin Med 1 (1): 4.  
  112. ^ Brown Alian G., Smale Terry C., King Trevor J., Hasenkamp Rainer, Thompson Ronald H. (1976). "Crystal and Molecular Structure of Compactin, a New Antifungal Metabolite from Penicillium brevicompactum". J. Chem. Soc., Perkin Trans. 1 1976: 1165–1170.  
  113. ^ Steinberg, Daniel. The Cholesterol Wars: The Skeptics vs. The Preponderance of Evidence. Academic Press, 2007, pp. 6–9.
  114. ^ "Randomised trial of cholesterol lowering in 4444 patients with coronary heart disease: the Scandinavian Simvastatin Survival Study (4S)". Lancet 344 (8934): 1383–9. November 1994.  
  115. ^ "National Inventors Hall of Fame Honors 2012 Inductees". PRNewswire. Retrieved May 11, 2014. 
  116. ^ "How One Scientist Intrigued by Molds Found First Statin". Wall Street Journal. Retrieved May 11, 2014. 
  117. ^ Wolozin B, Wang SW, Li NC, Lee A, Lee TA, Kazis LE (July 19, 2007). "Simvastatin is associated with a reduced incidence of dementia and Parkinson's disease". BMC Medicine 5 (1): 20.  
  118. ^ Khurana V, Bejjanki HR, Caldito G, Owens MW (May 2007). "Statins reduce the risk of lung cancer in humans: a large case-control study of US veterans". Chest 131 (5): 1282–1288.  
  119. ^ Klein BE, Klein R, Lee KE, Grady LM (June 2006). "Statin use and incident nuclear cataract". JAMA 295 (23): 2752–8.  
  120. ^ Golomb BA, Dimsdale JE, White HL, Ritchie JB, Criqui MH (April 2008). "Reduction in blood pressure with statins: results from the UCSD Statin Study, a randomized trial". Arch. Intern. Med. 168 (7): 721–7.  
  121. ^ Drapala, A; Sikora, M; Ufnal, M (Sep 2014). "Statins, the renin-angiotensin-aldosterone system and hypertension - a tale of another beneficial effect of statins.". Journal of the renin-angiotensin-aldosterone system : JRAAS 15 (3): 250–8.  
  122. ^ Mondul AM, Han M, Humphreys EB, Meinhold CL, Walsh PC, Platz EA (February 2011). "Association of statin use with pathological tumor characteristics and prostate cancer recurrence after surgery". Journal of Urology 185 (4): 1268–1273.  


Research continues into other areas where specific statins also appear to have a favorable effect, including dementia,[117] lung cancer,[118] nuclear cataracts,[119] hypertension,[120][121] and prostate cancer.[122]


To market statins effectively, Merck had to convince the public of the dangers of high cholesterol, and doctors that statins were safe and would extend lives. As a result of public campaigns, people in the United States became familiar with their cholesterol numbers and the difference between "good" and "bad" cholesterol, and rival 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%.[8][114] In 1995, Zocor and Mevacor both made Merck over US$1 billion.[8] Endo was awarded the 2006 Japan Prize, and the Lasker-DeBakey Clinical Medical Research Award in 2008. For his "pioneering research into a new class of molecules" for "lowering cholesterol,"[115] Endo was inducted into the National Inventors Hall of Fame in Alexandria, Virginia in 2012. Michael C. 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."[116]

A link between cholesterol and cardiovascular disease, known as the lipid hypothesis, had already been suggested. Cholesterol is the main constituent of atheroma, the fatty lumps in the wall of arteries that occur in atherosclerosis and, when ruptured, cause the vast majority of heart attacks. Treatment consisted mainly of dietary measures, such as a low-fat diet, and poorly tolerated medicines, such as clofibrate, cholestyramine, and nicotinic acid. Cholesterol researcher Daniel Steinberg writes that while the Coronary Primary Prevention Trial of 1984 demonstrated cholesterol lowering could significantly reduce the risk of heart attacks and angina, physicians, including cardiologists, remained largely unconvinced.[113]

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.[8]

A British group isolated the same compound from Penicillium brevicompactum, named it compactin, and published their report in 1976.[112] The British group mentions antifungal properties, with no mention of HMG-CoA reductase inhibition.

In 1971, ergosterol) or cytoskeleton (isoprenoids).[85] The first agent they identified was mevastatin (ML-236B), a molecule produced by the fungus Penicillium citrinum.


Statin equivalent dosages
% LDL reduction (approx.) Atorvastatin Fluvastatin Lovastatin Pravastatin Rosuvastatin Simvastatin
10–20% 20 mg 10 mg 10 mg 5 mg
20–30% 40 mg 20 mg 20 mg 10 mg
30–40% 10 mg 80 mg 40 mg 40 mg 5 mg 20 mg
40–45% 20 mg 80 mg 80 mg 5–10 mg 40 mg
46–50% 40 mg 10–20 mg 80 mg*
50–55% 80 mg 20 mg
56–60% 40 mg
* 80-mg dose no longer recommended due to increased risk of rhabdomyolysis
Starting dose
Starting dose 10–20 mg 20 mg 10–20 mg 40 mg 10 mg; 5 mg if hypothyroid, >65 yo, Asian 20 mg
If higher LDL reduction goal 40 mg if >45% 40 mg if >25% 20 mg if >20% -- 20 mg if LDL >190 mg/dL (4.87 mmol/L) 40 mg if >45%
Optimal timing Anytime Evening With evening meals Anytime Anytime Evening

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.[111] Due to patent expiration, most of the block-buster branded statins have been generic since 2012, including atorvastatin, the largest-selling branded drug.

The oyster mushroom, a culinary mushroom, naturally contains lovastatin.

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.[110] The relative potency of pitavastatin has not yet been fully established.

Statin Image Brand name Derivation Metabolism[107]
Lipitor, Torvast Synthetic CYP3A4
Lipobay, Baycol. (Withdrawn from the market in August, 2001 due to risk of serious rhabdomyolysis) Synthetic various CYP3A isoforms[108]
Lescol, Lescol XL Synthetic CYP2C9
Mevacor, Altocor, Altoprev This is a naturally occurring, fermentation-derived compound. It is found in oyster mushrooms and red yeast rice. CYP3A4
Compactin This is a naturally occurring compound found in red yeast rice. CYP3A4
Livalo, Pitava Synthetic
Pravachol, Selektine, Lipostat Fermentation-derived. (A fermentation product of bacterium Nocardia autotrophica). Non CYP[109]
Crestor Synthetic CYP2C9 and CYP2C19
Zocor, Lipex Fermentation-derived. (Simvastatin is a synthetic derivate of a fermentation product ofAspergillus terreus.) CYP3A4
Simvastatin+Ezetimibe Vytorin Combination therapy
Lovastatin+Niacin extended-release Advicor Combination therapy
Atorvastatin+Amlodipine Besylate Caduet Combination therapy – Cholesterol+Blood Pressure
Simvastatin+Niacin extended-release Simcor Combination therapy

The statins are divided into two groups: fermentation-derived and synthetic. They include, along with brand names, which may vary between countries:

Available forms

  1. ^ The interactive pathway map can be edited at WikiPathways: "Statin_Pathway_WP430". 
}px; border:solid #ccc 1px; background-color:white;">
|}px|alt=Statin Pathway edit]]
Statin Pathway edit

Click on genes, proteins and metabolites below to link to respective articles. [§ 1]

In 2008, the JUPITER study showed benefit in those who had no history of high cholesterol or heart disease, but only elevated C-reactive protein levels.[103] The conclusions of this study are, however, controversial.[104][105][106]

  1. Improve endothelial function
  2. Modulate inflammatory responses
  3. Maintain plaque stability
  4. Prevent thrombus formation

As noted above, statins exhibit action beyond lipid-lowering activity in the prevention of atherosclerosis. The ASTEROID trial showed direct ultrasound evidence of atheroma regression during statin therapy.[101] Researchers hypothesize that statins prevent cardiovascular disease via four proposed mechanisms (all subjects of a large body of biomedical research):[102]

Other effects

Statins, by inhibiting the HMG CoA reductase pathway, simultaneously inhibit the production of both cholesterol and specific prenylated proteins (see diagram).This inhibitory effect on protein prenylation may be involved, at least partially, in the improvement of endothelial function, modulation of immune function, and other pleiotropic cardiovascular benefits of statins,[91][92][93][94][95][96] as well as in the fact that a number of other drugs that lower LDL have not shown the same cardiovascular risk benefits in studies as statins,[97] and may also account for certain of the benefits seen in cancer reduction with statins.[98] In addition, the inhibitory effect on protein prenylation may also be involved in a number of unwanted side effects associated with statins, including muscle pain (myopathy)[99] and elevated blood sugar (diabetes).[100]

Decreasing of specific protein prenylation

In rabbits, liver cells sense the reduced levels of liver cholesterol and seek to compensate by synthesizing LDL receptors to draw cholesterol out of the circulation.[90] This is accomplished via protease enzymes that cleave a protein called "membrane-bound sterol regulatory element binding protein", which migrates to the nucleus and causes increased production of various other proteins and enzymes, including the LDL receptor. The LDL receptor then relocates to the liver cell membrane and binds to passing LDL and VLDL particles (the "bad cholesterol" linked to disease). LDL and VLDL are drawn out of circulation into the liver, where the cholesterol is reprocessed into bile salts. These are excreted, and subsequently recycled mostly by an internal bile salt circulation.

Increasing LDL uptake

By inhibiting HMG-CoA reductase, statins block the pathway for synthesizing cholesterol in the liver. This is significant because most circulating cholesterol comes from internal manufacture rather than the diet. When the liver can no longer produce cholesterol, levels of cholesterol in the blood will fall. Cholesterol synthesis appears to occur mostly at night,[86] so statins with short half-lives are usually taken at night to maximize their effect. Studies have shown greater LDL and total cholesterol reductions in the short-acting simvastatin taken at night rather than the morning,[87][88] but have shown no difference in the long-acting atorvastatin.[89]

Inhibiting cholesterol synthesis

Statins act by competitively inhibiting HMG-CoA reductase, the first committed enzyme of the mevalonate pathway. Because statins are similar in structure to HMG-CoA on a molecular level, they will fit into the enzyme's active site and compete with the native substrate (HMG-CoA). This competition reduces the rate by which HMG-CoA reductase is able to produce mevalonate, the next molecule in the cascade that eventually produces cholesterol. A variety of natural statins are produced by Penecillium and Aspergillus fungi as secondary metabolites. These natural statins probably function to inhibit HMG-CoA reductase enzymes in bacteria and fungi that compete with the producer.[85]

The HMG-CoA reductase pathway, which is blocked by statins via inhibiting the rate limiting enzyme HMG-CoA reductase.
Atorvastatin bound to HMG-CoA reductase: PDB entry [84]

Mechanism of action

The 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.[83]

Consumption of grapefruit or grapefruit juice inhibits the metabolism of certain statins. Bitter oranges may have a similar effect.[80] 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[81] (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.[82]

Combining any statin with a fibrate or niacin, another category of lipid-lowering drugs, increases the risks for rhabdomyolysis to almost 6.0 per 10,000 person-years.[59] Monitoring liver enzymes and creatine kinase is especially prudent in those on high-dose statins or in those on statin/fibrate combinations, and mandatory in the case of muscle cramps or of deterioration in kidney function.

Drug interactions

Statins may reduce the risk of esophageal cancer,[68] colorectal cancer,[69] gastric cancer,[70][71] hepatocellular carcinoma,[72] and possibly prostate cancer.[73][74] They appear to have no effect on the risk of lung cancer,[75] kidney cancer,[76] breast cancer,[77] pancreatic cancer,[78] or bladder cancer.[79]

Several meta-analyses have found no increased risk of cancer, and some meta-analyses have found a reduced risk.[63][64][65][66][67]


Statins are associated with a slightly increased risk of diabetes (2-17% in one review).[61] Higher doses have a greater effect, but the decrease in cardiovascular disease outweighs the risk of developing diabetes.[62]


All commonly used statins show somewhat similar results, but the newer statins, characterized by longer pharmacological half-lives and more cellular specificity, have had a better ratio of efficacy to lower adverse effect rates. 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;[60] the risk of myopathy was suggested to be lowest with pravastatin and fluvastatin, probably because they are more hydrophilic and as a result have less muscle penetration. Lovastatin induces the expression of gene atrogin-1, which is believed to be responsible in promoting muscle fiber damage.[60]

Graham et al. (2004) reviewed records of over 250,000 patients treated from 1998 to 2001 with the statin drugs atorvastatin, cerivastatin, fluvastatin, lovastatin, pravastatin, and simvastatin.[59] The incidence of rhabdomyolyis 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 fibrate (fenofibrate or gemfibrozil) treatment. Cerivastatin was withdrawn by its manufacturer in 2001.


This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.