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药品详细

Emtricitabine (恩曲他滨 )

化学结构式图
中文名
恩曲他滨
英文名
Emtricitabine
分子式
Not Available
化学名
4-amino-5-fluoro-1-[(2R,5S)-2-(hydroxymethyl)-1,3-oxathiolan-5-yl]-1,2-dihydropyrimidin-2-one
分子量
Average: 247.247
Monoisotopic: 247.042690096
CAS号
143491-57-0
ATC分类
J05A Direct acting antivirals
药物类型
small molecule
阶段
商品名
Coviracil;Emtriva;Racivir;
同义名
emtricitabine;
基本介绍

Emtricitabine is a nucleoside reverse transcriptase inhibitor (NRTI) for the treatment of HIV infection in adults. Emtricitabine is an analogue of cytidine. The drug works by inhibiting reverse transcriptase, the enzyme that copies HIV RNA into new viral DNA.

生产厂家
  • Gilead sciences inc
封装厂家
参考
Synthesis Reference Not Available
General Reference
  1. Masho SW, Wang CL, Nixon DE: Review of tenofovir-emtricitabine. Ther Clin Risk Manag. 2007 Dec;3(6):1097-104. Pubmed
  2. Long MC, King JR, Acosta EP: Pharmacologic aspects of new antiretroviral drugs. Curr HIV/AIDS Rep. 2009 Feb;6(1):43-50. Pubmed
  3. Emtricitabine/tenofovir disoproxil fumarate. Drugs R D. 2004;5(3):160-1. Pubmed
  4. Goicoechea M, Best B: Efavirenz/emtricitabine/tenofovir disoproxil fumarate fixed-dose combination: first-line therapy for all? Expert Opin Pharmacother. 2007 Feb;8(3):371-82. Pubmed
剂型
Form Route Strength
Capsule Oral
规格
Unit description Cost Unit
Emtriva 200 mg capsule 21.75 USD capsule
化合物类型
Type small molecule
Classes
  • Pyrimidines and Derivatives
Substructures
  • Hydroxy Compounds
  • Aliphatic and Aryl Amines
  • Ethers
  • Oxathiolanes
  • Alcohols and Polyols
  • Pyrimidines and Derivatives
  • Heterocyclic compounds
  • Aromatic compounds
  • Acetals and Derivatives
  • Cyanamides
  • Aryl Halides
适应症
ANTIVIRALS 抗病毒;
药理
Indication Indicated, in combination with other antiretroviral agents, for the treatment of HIV-1 infection in adults and for postexposure prophylaxis of HIV infection in health care workers and others exposed occupationally or nonoccupationally via percutaneous injury or mucous membrane or nonintact skin contact with blood, tissues, or other body fluids associated with risk for transmission of the virus.
Pharmacodynamics Emtricitabine is a nucleoside reverse transcriptase inhibitor (NRTI) with activity against Human Immunodeficiency Virus Type 1 (HIV-1). Emtricitabine helps to block HIV reverse transcriptase, a chemical in your body (enzyme) that is needed for HIV to multiply. Emtricitabine is always used with other anti-HIV medicines to treat people with HIV infection. Emtricitabine may lower the amount of HIV in the blood (viral load). Emtricitabine may also help to increase the number of T cells called CD4 cells. Lowering the amount of HIV in the blood lowers the chance of death or infections that happen when your immune system is weak (opportunistic infections). People taking emtricitabine may still get opportunistic infections or other conditions that happen with HIV infection.
Mechanism of action Emtricitabine works by inhibiting reverse transcriptase, the enzyme that copies HIV RNA into new viral DNA. Emtricitabine is a synthetic nucleoside analogue of cytidine. It is phosphorylated by cellular enzymes to form emtricitabine 5'-triphosphate, which is responsible for the inhibition of HIV-1 reverse transcriptase. It competes with the natural substrate deoxycytidine 5'-triphosphate and incorporates into nascent viral DNA, resulting in early chain termination. Therefore emtricitabine inhibits the activity of HIV-1 reverse transcriptase (RT) both by competing with the natural substrate deoxycytidine 5'-triphosphate and by its incorporation into viral DNA. By inhibiting HIV-1 reverse transcriptase, emtricitabine can help to lower the amount of HIV, or "viral load", in a patient's body and can indirectly increase the number of immune system cells (called T cells or CD4+ T-cells). Both of these changes are associated with healthier immune systems and decreased likelihood of serious illness.
Absorption Rapidly absorbed (mean absolute bioavailability of 93% for capsules, and 75% for solution). Food does not effect absorption.
Volume of distribution Not Available
Protein binding Very low (less than 4%)
Metabolism

Minimally transformed (13%), most appears unchanged in urine (86%). The biotransformation of emtricitabine includes oxidation of the thiol moiety to form the 3′-sulfoxide diastereomers (~ 9% of dose) and conjugation with glucuronic acid to form 2′-O-glucuronide (~ 4% of dose). In vitro studies indicate emtricitabine is not an inhibitor or cytochrome P450 enzymes.
Route of elimination The renal clearance of emtricitabine is greater than the estimated creatinine clearance, suggesting elimination by both glomerular filtration and active tubular secretion.
Half life 10 hours
Clearance
  • 302 +/- 94 mL/min [Renal Function Creatinine Clearance>80 ml/min]
  • 168 +/- 10 mL/min [Renal Function Creatinine Clearance 50-80 ml/min]
  • 138 +/- 28 mL/min [Renal Function Creatinine Clearance 30-49 ml/min]
  • 99 +/- 6 mL/min [Renal Function Creatinine Clearance<30 ml/min]
  • 64 +/- 12 mL/min [ESRD patients requiring dialysis]
Toxicity Symptoms of overdose include serious liver problems (hepatotoxicity, with liver enlargement and fat in the liver called steatosis) or a lactic acidosis (buildup of an acid in the blood).
Affected organisms
  • Human Immunodeficiency Virus
Pathways Not Available
理化性质
Properties
State solid
Melting point 136-140 oC
Experimental Properties
Property Value Source
water solubility 112 mg/mL PhysProp
logP -1.4 PhysProp
pKa 2.65 Various sources
Predicted Properties
Property Value Source
water solubility 2.00e+00 g/l ALOGPS
logP -0.80 ALOGPS
logP -0.90 ChemAxon Molconvert
logS -2.09 ALOGPS
pKa ChemAxon Molconvert
hydrogen acceptor count 5 ChemAxon Molconvert
hydrogen donor count 2 ChemAxon Molconvert
polar surface area 88.15 ChemAxon Molconvert
rotatable bond count 2 ChemAxon Molconvert
refractivity 55.37 ChemAxon Molconvert
polarizability 21.79 ChemAxon Molconvert
药物相互作用
Drug Interaction
Valganciclovir The adverse/toxic effects of reverse transcriptase inhibitors (nucleoside), such as Emtricitabine, may be enhanced by Valganciclovir. There is a risk of hematologic toxicity. Diligent monitoring during concomitant therapy is recommended.
食物相互作用
  • Take without regard to meals.

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