| Drug ID: | D131 |
| Drug Name: | Ezetimibe |
| Synonyms: |
Ezetimibe
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| Type: | Chemical drug |
| DrugBank ID: |
DB00973
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| DrugBank Description: |
Ezetimibe is a lipid-lowering compound that inhibits intestinal cholesterol and phytosterol absorption. The discovery and research of this drug began in the early 1990s, after the intravenous administration of radiolabelled ezetimibe in rats revealed that it was being localized within enterocytes of the intestinal villi - this prompted studies investigating the effect of ezetimibe on intestinal cholesterol absorption. Ezetimibe is used as an adjunctive therapy to a healthy diet to lower cholesterol levels in primary hyperlipidemia, mixed hyperlipidemia, homozygous familial hypercholesterolemia (HoFH), and homozygous sitosterolemia (phytosterolemia).
Unlike other classes of cholesterol-reducing compounds including statins and bile acid sequestrants, ezetimibe has a distinct mechanism of action involving the sterol transporter Niemann-Pick C1-Like 1 (NPC1L1), and is unique in that it does not affect the absorption of fat-soluble nutrients such as fat-soluble vitamins, triglycerides, or bile acids. In genetically NPC1L1-deficient mice, a 70% reduction in intestinal cholesterol absorption was seen, and these mice were insensitive to ezetimibe treatment - it was determined based on these findings that NPC1L1 plays an essential role in promoting intestinal cholesterol uptake via an ezetimibe-sensitive pathway. By interfering with the intestinal uptake of cholesterol and phytosterols, ezetimibe reduces the delivery of intestinal cholesterol to the liver.
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| PubChem ID: |
150311
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| CasNo: |
163222-33-1
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| Repositioning for NAFLD: |
Yes
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| SMILES: |
C(C[C@H](O)c1ccc(cc1)F)[C@@H]1[C@H](N(C1=O)c1ccc(cc1)F)c1ccc(cc1)O
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| Structure: |
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| InChiKey: |
OLNTVTPDXPETLC-XPWALMASSA-N
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| Molecular Weight: |
409.432
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| DrugBank Targets: |
Niemann-Pick C1-like protein 1 inhibitor; Sterol O-acyltransferase 1 inhibitor; Aminopeptidase N other
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| DrugBank MoA: |
Ezetimibe mediates its blood cholesterol-lowering effect via selectively inhibiting the absorption of cholesterol and phytosterol by the small intestine without altering the absorption of fat-soluble vitamins and nutrients. The primary target of ezetimibe is the cholesterol transport protein Niemann-Pick C1-Like 1 (NPC1L1) protein. NPC1L1 is expressed on enterocytes/gut lumen (apical) as well as the hepatobiliary (canalicular) interface and plays a role in facilitating internalization of free cholesterol into the enterocyte in conjunction with the adaptor protein 2 (AP2) complex and clathrin. Once cholesterol in the gut lumen or bile is incorporated into the cell membrane of enterocytes, it binds to the sterol-sensing domain of NPC1L1 and forms a NPC1L1/cholesterol complex. The complex is then internalized or endocytosed by joining to AP2 clathrin, forming a vesicle complex that is translocated for storage in the endocytic recycling compartment.
Ezetimibe does not require exocrine pancreatic function for its pharmacological activity; rather, it localizes and appears to act at the brush border of the small intestine. Ezetimibe selectively blocks the NPC1L1 protein in the jejunal brush border, reducing the uptake of intestinal lumen micelles into the enterocyte. Overall, ezetimibe causes a decrease in the delivery of intestinal cholesterol to the liver and reduction of hepatic cholesterol stores and an increase in clearance of cholesterol from the blood. While the full mechanism of action of ezetimibe in reducing the entry of cholesterol into both enterocytes and hepatocytes is not fully understood, one study proposed that ezetimibe prevents the NPC1L1/sterol complex from interacting with AP2 in clathrin coated vesicles and induces a conformational change in NPC1L1, rendering it incapable of binding to sterols. Another study suggested that ezetimibe disrupts the function of other protein complexes involved in regulating cholesterol uptake, including the CAV1–annexin 2 heterocomplex.
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| DrugBank Pharmacology: |
Ezetimibe was shown to reduce the levels of total cholesterol (total-C), low-density lipoprotein cholesterol (LDL-C), apoprotein B (Apo B), non-high-density lipoprotein cholesterol (non-HDL-C), and triglycerides (TG), and increase high-density lipoprotein cholesterol (HDL-C) in patients with hyperlipidemia. This therapeutic effect was more profound when ezetimibe was co-administered with a statin or fenofibrate compared to either treatment alone. In clinical trials involving patients with homozygous and heterozygous familial hypercholesterolemia and in those with sitosterolemia, a recommended therapeutic dose of ezetimibe was effective in reducing the LDL levels by 15-20% while increasing HDL-C by 2.5-5%.
The effects of increased exposure to ezetimibe secondary to moderate-severe hepatic impairment have not been assessed - patients meeting these criteria should avoid the use of ezetimibe. Post-marketing reports indicate the potential for myopathy and rhabdomyolysis in patients taking ezetimibe, and this risk appears to be exacerbated in patients concurrently receiving, or having recently received, statin therapy.
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| DrugBank Indication: |
Ezetimibe is indicated to reduce elevated total-C, LDL-C, Apo B, and non-HDL-C in patients with primary hyperlipidemia, alone or in combination with an HMG-CoA reductase inhibitor (statin). It is also indicated to reduce elevated total-C, LDL-C, Apo B, and non-HDL-C in patients with mixed hyperlipidemia in combination with fenofibrate, and to reduce elevated total-C and LDL-C in patients with homozygous familial hypercholesterolemia (HoFH), in combination with atorvastatin or simvastatin. Ezetimibe may also be used to reduce elevated sitosterol and campesterol in patients with homozygous sitosterolemia (phytosterolemia).
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| Targets: |
SOAT1 inhibitor;
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| Therapeutic Category: |
Enhance lipid metabolism
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| Clinical Trial Progress: |
Phase 2 completed (NCT01766713: Ezetimibe improved FRS whereas placebo did not. FRS and CAC scores improved in a greater proportion of patients with ezetimibe; this trend did not reach significance. These findings indicate the utility and feasibility of monitoring cardiovascular risk in a NASH trial. The utility of CAC scores may be higher in trials of longer duration (⩾52 weeks) and with older patients (age ⩾45).)
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| Latest Progress: |
Under clinical trials
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