Fibrate

Last updated
Fibrates
Drug class
Fenofibrate structure.svg
Fenofibrate, one of the most popular fibrates
Class identifiers
Use hypertriglyceridemia and hypercholesterolaemia
ATC code C10AB
Biological target PPAR
Clinical data
WebMD MedicineNet  
External links
MeSH D058607
Legal status
In Wikidata

In pharmacology, the fibrates are a class of amphipathic carboxylic acids and esters. They are derivatives of fibric acid (phenoxyisobutyric acid). They are used for a range of metabolic disorders, mainly hypercholesterolemia (high cholesterol), and are therefore hypolipidemic agents.

Contents

Medical uses

Fibrates improve atherogenic dyslipidemia characterized by high triglyceride and/or low HDL-C levels and elevated concentrations of small dense LDL particles, with or without high LDL-C levels. Fibrates may be compared to statin drugs, which reduce LDL-cholesterol (LDL-C) and have only limited effects on other lipid parameters. Clinical trials have shown that the combination of statins and fibrates results in a significantly greater reduction in LDL-C and triglyceride levels and greater increases in high-density lipoprotein cholesterol (HDL-C) compared with monotherapy with either drug. [1] Fibrates are used in accessory therapy in many forms of hypercholesterolemia, but the combination of some fibrates (e.g., gemfibrozil) with statins is contraindicated due to an increased risk of rhabdomyolysis. [2]

Fibrates stimulate peroxisome proliferator activated receptor (PPAR) alpha, which controls the expression of gene products that mediate the metabolism of triglycerides (TG) and high-density lipoprotein (HDL). As a result, synthesis of fatty acids, TG and VLDL is reduced, whilst that of lipoprotein lipase, which catabolises TG, is enhanced. In addition, production of Apo A1 and ATP binding cassette A1 is up-regulated, leading to increased reverse cholesterol transport via HDL. Consequently, fibrates reduce TG by up to 50% and increase HDL-C by up to 20%, but LDL-C changes are variable. Fewer large-scale trials have been conducted with fibrates than with statins and the results are less conclusive, but reduced rates of cardiovascular disease have been reported with fibrate therapy in the subgroup of patients with low HDL-C levels and elevated TG (e.g. TG > 2.3 mmol/L (200 mg/dL)). Fibrates are usually well tolerated but share a similar side-effect profile to statins. In addition, they may increase the risk of cholelithiasis and prolong the action of anticoagulants. Accumulating evidence suggests that they may also have a protective effect against diabetic microvascular complications.

Clinical trials do support their use as monotherapy agents. Fibrates reduce the number of non-fatal heart attacks, but do not improve all-cause mortality and are therefore indicated only in those not tolerant to statins. [3] [4] [5]

Although less effective in lowering LDL levels, the ability of fibrates to increase HDL and lower triglyceride levels seems to reduce insulin resistance when the dyslipidemia is associated with other features of the metabolic syndrome (hypertension and diabetes mellitus type 2). [6] They are therefore used in many hyperlipidemias. Due to a rare paradoxical decrease in HDL-C seen in some patients on fenofibrate, as per US FDA label change, it is recommended that the HDL-C levels be checked within the first few months after initiation of fibrate therapy. If a severely depressed HDL-C level is detected, fibrate therapy should be withdrawn, and the HDL-C level monitored until it has returned to baseline.[ citation needed ]

Side effects

Most fibrates can cause mild stomach upset and myopathy (muscle pain with CPK elevations). Fibrates decrease the synthesis of bile acid by down-regulation of cholesterol 7 alpha-hydroxylase and sterol 27-hydroxylase expression, therefore making it easier for cholesterol to precipitate and increasing the risk for gallstones.

In combination with statin drugs, fibrates cause an increased risk of rhabdomyolysis, idiosyncratic destruction of muscle tissue, leading to kidney failure. The less lipophilic statins are less prone to cause this reaction, and are probably safer to be combined with fibrates than the more lipophilic statins are.

Drug toxicity includes acute kidney injury. [7]

Pharmacology

PPAR PPAR-diagram.png
PPAR

Although used clinically since at least 1962, the mechanism of action of fibrates remained unelucidated until the 1990s, when it was discovered that fibrates activate peroxisome proliferator-activated receptors (PPARs), especially PPARα. [8] The PPARs are a class of intracellular receptors that modulate carbohydrate and fat metabolism and adipose tissue differentiation.

Activating PPARs induces the transcription of a number of genes that facilitate lipid metabolism.

Fibrates are pharmacologically related to the thiazolidinediones, a novel class of anti-diabetic drugs that also act on PPARs (more specifically PPARγ)[ citation needed ]

Fibrates are a substrate of (metabolized by) CYP3A4. [8]

Fibrates have been shown to extend lifespan in the roundworm C. elegans. [9]

Members

See also

Related Research Articles

<span class="mw-page-title-main">Cholesterol</span> Sterol biosynthesized by all animal cells

Cholesterol is the principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.

High-density lipoprotein (HDL) is one of the five major groups of lipoproteins. Lipoproteins are complex particles composed of multiple proteins which transport all fat molecules (lipids) around the body within the water outside cells. They are typically composed of 80–100 proteins per particle. HDL particles enlarge while circulating in the blood, aggregating more fat molecules and transporting up to hundreds of fat molecules per particle.

<span class="mw-page-title-main">Low-density lipoprotein</span> One of the five major groups of lipoprotein

Low-density lipoprotein (LDL) is one of the five major groups of lipoprotein that transport all fat molecules around the body in extracellular water. These groups, from least dense to most dense, are chylomicrons, very low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), low-density lipoprotein (LDL) and high-density lipoprotein (HDL). LDL delivers fat molecules to cells. LDL has been associated with the progression of atherosclerosis.

Lipid-lowering agents, also sometimes referred to as hypolipidemic agents, cholesterol-lowering drugs, or antihyperlipidemic agents are a diverse group of pharmaceuticals that are used to lower the level of lipids and lipoproteins, such as cholesterol, in the blood (hyperlipidemia). The American Heart Association recommends the descriptor 'lipid lowering agent' be used for this class of drugs rather than the term 'hypolipidemic'.

<span class="mw-page-title-main">Hypercholesterolemia</span> High levels of cholesterol in the blood

Hypercholesterolemia, also called high cholesterol, is the presence of high levels of cholesterol in the blood. It is a form of hyperlipidemia, hyperlipoproteinemia, and dyslipidemia.

Dyslipidemia is a metabolic disorder characterized by abnormally high or low amounts of any or all lipids or lipoproteins in the blood. Dyslipidemia is a risk factor for the development of atherosclerotic cardiovascular diseases (ASCVD), which include coronary artery disease, cerebrovascular disease, and peripheral artery disease. Although dyslipidemia is a risk factor for ASCVD, abnormal levels don't mean that lipid lowering agents need to be started. Other factors, such as comorbid conditions and lifestyle in addition to dyslipidemia, is considered in a cardiovascular risk assessment. In developed countries, most dyslipidemias are hyperlipidemias; that is, an elevation of lipids in the blood. This is often due to diet and lifestyle. Prolonged elevation of insulin resistance can also lead to dyslipidemia. Likewise, increased levels of O-GlcNAc transferase (OGT) may cause dyslipidemia.

<span class="mw-page-title-main">Atorvastatin</span> Cholesterol-lowering medication

Atorvastatin is a statin medication used to prevent cardiovascular disease in those at high risk and to treat abnormal lipid levels. For the prevention of cardiovascular disease, statins are a first-line treatment. It is taken by mouth.

<span class="mw-page-title-main">Pravastatin</span> Cholesterol lowering medication in the statin class

Pravastatin, sold under the brand name Pravachol among others, is a statin medication, used for preventing cardiovascular disease in those at high risk and treating abnormal lipids. It is suggested to be used together with diet changes, exercise, and weight loss. It is taken by mouth.

<span class="mw-page-title-main">Hypertriglyceridemia</span> High triglyceride blood levels

Hypertriglyceridemia is the presence of high amounts of triglycerides in the blood. Triglycerides are the most abundant fatty molecule in most organisms. Hypertriglyceridemia occurs in various physiologic conditions and in various diseases, and high triglyceride levels are associated with atherosclerosis, even in the absence of hypercholesterolemia and predispose to cardiovascular disease.

<span class="mw-page-title-main">Combined hyperlipidemia</span> Medical condition

Combined hyperlipidemia is a commonly occurring form of hypercholesterolemia characterised by increased LDL and triglyceride concentrations, often accompanied by decreased HDL. On lipoprotein electrophoresis it shows as a hyperlipoproteinemia type IIB. It is the most commonly inherited lipid disorder, occurring in around one in 200 persons. In fact, almost one in five individuals who develop coronary heart disease before the age of 60 have this disorder.

<span class="mw-page-title-main">Gemfibrozil</span> Medication

Gemfibrozil, sold under the brand name Lopid among others, is a medication used to treat abnormal blood lipid levels. It is generally less preferred than statins. Use is recommended together with dietary changes and exercise. It is unclear if it changes the risk of heart disease. It is taken by mouth.

Hyperlipidemia is abnormally high levels of any or all lipids or lipoproteins in the blood. The term hyperlipidemia refers to the laboratory finding itself and is also used as an umbrella term covering any of various acquired or genetic disorders that result in that finding. Hyperlipidemia represents a subset of dyslipidemia and a superset of hypercholesterolemia. Hyperlipidemia is usually chronic and requires ongoing medication to control blood lipid levels.

<span class="mw-page-title-main">Torcetrapib</span> Chemical compound

Torcetrapib was a drug being developed to treat hypercholesterolemia and prevent cardiovascular disease. Its development was halted in 2006 when phase III studies showed excessive all-cause mortality in the treatment group receiving a combination of atorvastatin (Lipitor) and torcetrapib.

<span class="mw-page-title-main">Fenofibrate</span> Drug of the fibrate class, mainly used to reduce cholesterol levels

Fenofibrate, is an oral medication of the fibrate class used to treat abnormal blood lipid levels. It is less commonly used compared than statins because it treats a different type of cholesterol abnormality to statins. While statins have strong evidence for reducing heart disease and death, there is evidence to suggest that fenofibrate also reduces the risk of heart disease and death. However, this seems only to apply to specific populations of people with elevated triglyceride levels and reduced high-density lipoprotein (HDL) cholesterol. Its use is recommended together with dietary changes.

<span class="mw-page-title-main">Familial hypercholesterolemia</span> Genetic disorder characterized by high cholesterol levels

Familial hypercholesterolemia (FH) is a genetic disorder characterized by high cholesterol levels, specifically very high levels of low-density lipoprotein cholesterol, in the blood and early cardiovascular diseases. The most common mutations diminish the number of functional LDL receptors in the liver or produce abnormal LDL receptors that never go to the cell surface to function properly. Since the underlying body biochemistry is slightly different in individuals with FH, their high cholesterol levels are less responsive to the kinds of cholesterol control methods which are usually more effective in people without FH. Nevertheless, treatment is usually effective.

<span class="mw-page-title-main">Colesevelam</span> Pharmaceutical drug

Colesevelam is a bile acid sequestrant administered orally. It was developed by GelTex Pharmaceuticals and later acquired by Genzyme. It is marketed in the US by Daiichi Sankyo under the brand name Welchol and elsewhere by Genzyme as Cholestagel. In Canada, it is marketed by Valeant as Lodalis.

The chronic endothelial injury hypothesis is one of two major mechanisms postulated to explain the underlying cause of atherosclerosis and coronary heart disease (CHD), the other being the lipid hypothesis. Although an ongoing debate involving connection between dietary lipids and CHD sometimes portrays the two hypotheses as being opposed, they are in no way mutually exclusive. Moreover, since the discovery of the role of LDL cholesterol (LDL-C) in the pathogenesis of atherosclerosis, the two hypotheses have become tightly linked by a number of molecular and cellular processes.

Fenofibrate/pravastatin, sold under the brand name Pravafenix, is a combination medication used for the treatment of hypercholesterolemia in adults whose low-density lipoprotein (LDL) cholesterol is already being controlled with pravastatin alone but who still need to improve their cholesterol levels and to reduce their levels of triglycerides. It contains fenofibrate and pravastatin. It is taken by mouth.

Cardiovascular agents are drugs used to treat diseases associated with the heart or blood vessels. These medications are available for purchase only with a physician’s prescription. They include, but are not limited to, drugs that target hypertension (antihypertensives), hyperlipidemia (antihyperlipidemics) and blood clotting (blood-thinners) to reduce the risk of cardiovascular diseases.

Atherothrombosis Intervention in Metabolic Syndrome with Low HDL/High Triglycerides: Impact on Global Health Outcomes was a randomized control trial designed to assess the efficacy of niacin (extended-release) added to statin therapy in reducing cardiovascular events in patients with established atherosclerotic cardiovascular disease (ASCVD). These patients had well-controlled low-density lipoprotein (LDL) cholesterol but persistently low high-density lipoprotein (HDL) cholesterol and elevated triglycerides. 3,414 patients with established ASCVD were enrolled. The mean follow-up period was three years. The trial was stopped early due to a lack of efficacy and a trend towards an increase in the incidence of ischemic stroke.

References

  1. ↑ Grundy, Scott M.; Vega, Gloria L.; Yuan, Zhong; Battisti, Wendy P.; Brady, William E.; Palmisano, Joanne (2005). "Effectiveness and tolerability of simvastatin plus fenofibrate for combined hyperlipidemia (The SAFARI trial)". The American Journal of Cardiology. 95 (4): 462–468. doi:10.1016/j.amjcard.2004.10.012. PMID   15695129.
  2. ↑ Steiner G (December 2007). "Atherosclerosis in type 2 diabetes: a role for fibrate therapy?". Diabetes & Vascular Disease Research. 4 (4): 368–74. doi: 10.3132/dvdr.2007.067 . PMID   18158710. S2CID   31624928.
  3. ↑ Abourbih S, Filion KB, Joseph L, Schiffrin EL, Rinfret S, Poirier P, et al. (October 2009). "Effect of fibrates on lipid profiles and cardiovascular outcomes: a systematic review". The American Journal of Medicine. 122 (10): 962.e1–8. doi:10.1016/j.amjmed.2009.03.030. PMID   19698935.
  4. ↑ Jun M, Foote C, Lv J, et al. (2010). "Effects of fibrates on cardiovascular outcomes: a systematic review and meta-analysis". Lancet. 375 (9729): 1875–1884. doi:10.1016/S0140-6736(10)60656-3. PMID   20462635. S2CID   15570639.
  5. ↑ Jakob T, Nordmann AJ, Schandelmaier S, Ferreira-González I, Briel M (November 2016). Cochrane Heart Group (ed.). "Fibrates for primary prevention of cardiovascular disease events". The Cochrane Database of Systematic Reviews. 11 (3): CD009753. doi:10.1002/14651858.CD009753.pub2. PMC   6464497 . PMID   27849333.
  6. ↑ Wysocki J, Belowski D, Kalina M, Kochanski L, Okopien B, Kalina Z (April 2004). "Effects of micronized fenofibrate on insulin resistance in patients with metabolic syndrome". International Journal of Clinical Pharmacology and Therapeutics. 42 (4): 212–7. doi:10.5414/cpp42212. PMID   15124979.
  7. ↑ Zhao YY, Weir MA, Manno M, Cordy P, Gomes T, Hackam DG, et al. (April 2012). "New fibrate use and acute renal outcomes in elderly adults: a population-based study". Annals of Internal Medicine. 156 (8): 560–9. doi:10.7326/0003-4819-156-8-201204170-00003. PMID   22508733. S2CID   207536477.
  8. 1 2 Lee, T.K. "Fibrates in Perspective: Answering an Age-Old Question" (PDF). Perspectives in Cardiology. 20 (6): 34–39.
  9. ↑ Brandstädt, Sven; Schmeisser, Kathrin; Zarse, Kim; Ristow, Michael (2013-04-08). "Lipid-lowering fibrates extend C. elegans lifespan in a NHR-49/PPARalpha-dependent manner". Aging . 5 (4): 270–275. doi: 10.18632/aging.100548 . PMC   3651519 . PMID   23603800.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.