Tìm theo
Levothyroxine
Các tên gọi khác (11 ) :
  • 3,3',5,5'-Tetraiodo-L-thyronine
  • 3,5,3',5'-TETRAIODO-L-thyronine
  • 4-(4-Hydroxy-3,5-diiodophenoxy)-3,5-diiodo-L-phenylalanine
  • L-T4
  • L-Thyroxine
  • Levothyroxin
  • Levothyroxine
  • LT4
  • O-(4-Hydroxy-3,5-diidophenyl)-3,5-diiodo-L-tyrosine
  • O-(4-Hydroxy-3,5-diiodophenyl)-3,5-diiodo-L-tyrosine
  • T4
Hormon, Nội tiết tố
Thuốc Gốc
Small Molecule
CAS: 51-48-9
ATC: H03AA01
ĐG : Abbott Laboratories Ltd. , http://www.abbott.com
CTHH: C15H11I4NO4
PTK: 776.87
The major hormone derived from the thyroid gland. Thyroxine is synthesized via the iodination of tyrosines (monoiodotyrosine) and the coupling of iodotyrosines (diiodotyrosine) in the thyroglobulin. Thyroxine is released from thyroglobulin by proteolysis and secreted into the blood. Thyroxine is peripherally deiodinated to form triiodothyronine which exerts a broad spectrum of stimulatory effects on cell metabolism. [PubChem]
Nhận Dạng Quốc Tế & Đặc Tính Hóa Học
Công thức hóa học
C15H11I4NO4
Phân tử khối
776.87
Monoisotopic mass
776.686681525
InChI
InChI=1S/C15H11I4NO4/c16-8-4-7(5-9(17)13(8)21)24-14-10(18)1-6(2-11(14)19)3-12(20)15(22)23/h1-2,4-5,12,21H,3,20H2,(H,22,23)/t12-/m0/s1
InChI Key
InChIKey=XUIIKFGFIJCVMT-LBPRGKRZSA-N
IUPAC Name
(2S)-2-amino-3-[4-(4-hydroxy-3,5-diiodophenoxy)-3,5-diiodophenyl]propanoic acid
Traditional IUPAC Name
levothyroxine
SMILES
N[C@@H](CC1=CC(I)=C(OC2=CC(I)=C(O)C(I)=C2)C(I)=C1)C(O)=O
Độ tan chảy
235.5 °C
Độ hòa tan
0.105 mg/mL
logP
4
logS
-4.9
pKa (strongest acidic)
0.27
pKa (Strongest Basic)
9.43
PSA
92.78 Å2
Refractivity
126.79 m3·mol-1
Polarizability
49.4 Å3
Rotatable Bond Count
5
H Bond Acceptor Count
4
H Bond Donor Count
3
Physiological Charge
0
Number of Rings
2
Bioavailability
1
Dược Lực Học : Levothyroxine (T4) is a synthetically prepared levo isomer of thyroxine, the major hormone secreted from the thyroid gland. Thyroxine is released from thyroglobulin by proteolysis and secreted into the blood. Thyroxine is peripherally deiodinated to form triiodothyronine (T3) which exerts a broad spectrum of stimulatory effects on cell metabolism. Thyroid hormone increases the metabolic rate of cells of all tissues in the body. In the fetus and newborn, thyroid hormone is important for the growth and development of all tissues including bones and the brain. In adults, thyroid hormone helps to maintain brain function, food metabolism, and body temperature, among other effects. The symptoms of thyroid deficiency relieved by levothyroxine include slow speech, lack of energy, weight gain, hair loss, dry thick skin and unusual sensitivity to cold.
Cơ Chế Tác Dụng : The major hormone derived from the thyroid gland. Thyroxine is synthesized via the iodination of tyrosines (monoiodotyrosine) and the coupling of iodotyrosines (diiodotyrosine) in the thyroglobulin. Thyroxine is released from thyroglobulin by proteolysis and secreted into the blood. Thyroxine is peripherally deiodinated to form triiodothyronine which exerts a broad spectrum of stimulatory effects on cell metabolism. [PubChem] Levothyroxine acts like the endogenous thyroid hormone thyroxine (T4, a tetra-iodinated tyrosine derivative). In the liver and kidney, T4 is converted to T3, the active metabolite. In order to increase solubility, the thyroid hormones attach to thyroid hormone binding proteins, thyroxin-binding globulin, and thyroxin-binding prealbumin (transthyretin). Transport and binding to thyroid hormone receptors in the cytoplasm and nucleus then takes place. Thus by acting as a replacement for natural thyroxine, symptoms of thyroxine deficiency are relieved.
Dược Động Học :
▧ Absorption :
Bioavailability varies from 48% to 80%. Human studies have confirmed the importance of an intact jejunum and ileum for levothyroxine absorption and have shown some absorption from the duodenum.
▧ Protein binding :
> 99% to serum proteins, including thyroxine-binding globulin (TBG), thyroxine-binding prealbumin (TBPA), and albumin (TBA)
▧ Metabolism :
Approximately 70% of secreted T4 is deiodinated to equal amounts of T3 and reverse triiodothyronine (rT3), which is calorigenically inactive. Elimination of T4 and T3 involves hepatic conjugation to glucuronic and sulfuric acids. The hormones undergo enterohepatic circulation as conjugates are hydrolyzed in the intestine and reabsorbed. Conjugated compounds that reach the colon are hydrolyzed and eliminated as free compounds in the feces. Other minor T4 metabolites have been identified.
▧ Route of Elimination :
Thyroid hormones are primarily eliminated by the kidneys.
▧ Half Life :
T4, 6 to 7 days. T3, 1 to 2 days.
Độc Tính : LD50=20 mg/kg (orally in rat). Hypermetabolic state indistinguishable from thyrotoxicosis of endogenous origin. Symptoms of thyrotoxicosis include weight loss, increased appetite, palpitations, nervousness, diarrhea, abdominal cramps, sweating, tachycardia, increased pulse and blood pressure, cardiac arrhythmias, tremors, insomnia, heat intolerance, fever, and menstrual irregularities.
Chỉ Định : For use alone or in combination with antithyroid agents to treat hypothyroidism, goiter, chronic lymphocytic thyroiditis, myxedema coma, and stupor.
Tương Tác Thuốc :
  • Acenocoumarol The thyroid hormone, levothyroxine, increase the anticoagulant effect of acenocoumarol.
  • Anisindione The thyroid hormone, levothyroxine, increase the anticoagulant effect of anisindione.
  • Calcium Calcium decreases absorption of levothyroxine
  • Calcium Acetate Calcium salts such as calcium acetate may diminish the therapeutic effect of thyroid products such as levothyroxine. Separate the doses of the thyroid product and the oral calcium supplement by at least 4 hours. Monitor for decreased therapeutic effects of thyroid products if an oral calcium supplement is initiated/dose increased, or increased effects if an oral calcium supplement is discontinued/dose decreased.
  • Calcium Chloride Calcium salts such as calcium chloride may diminish the therapeutic effect of thyroid products such as levothyroxine. Separate the doses of the thyroid product and the oral calcium supplement by at least 4 hours. Monitor for decreased therapeutic effects of thyroid products if an oral calcium supplement is initiated/dose increased, or increased effects if an oral calcium supplement is discontinued/dose decreased.
  • Cholestyramine The resin, cholestyramine, decreases the absorption of the thyroid hormone, levothyroxine.
  • Colestipol The resin, colestipol, decreases the absorption of the thyroid hormone, levothyroxine.
  • Dicoumarol The thyroid hormone, levothyroxine, increase the anticoagulant effect of dicumarol.
  • Digoxin The thyroid hormone, levothyroxine, decreases the effect of digoxin.
  • Iron Iron decreases absorption of levothyroxine
  • Iron Dextran Iron decreases the absorption of levothyroxine
  • Raloxifene Raloxifene decreases absorption of levothyroxine
  • Sucralfate Sucralfate decreases the effect of levothyroxine
  • Warfarin Levothyroxine may contribute to the anticoagulant effect of warfarin by increasing the metabolism of vitamin K-dependent clotting factors. Monitor for changes in prothrombin time and anticoagulant effects if levothyroxine is initiated, discontinued or dose changed.
Liều Lượng & Cách Dùng : Powder, for solution - Parenteral - 100 mcg/ml
Powder, for solution - Parenteral - 40 mcg/ml
Tablet - Oral - 100 mcg
Tablet - Oral - 112 mcg
Tablet - Oral - 125 mcg
Tablet - Oral - 137 mcg
Tablet - Oral - 150 mcg
Tablet - Oral - 175 mcg
Tablet - Oral - 200 mcg
Tablet - Oral - 25 mcg
Tablet - Oral - 300 mcg
Tablet - Oral - 50 mcg
Tablet - Oral - 75 mcg
Tablet - Oral - 88 mcg
Dữ Kiện Thương Mại
Giá thị trường
Nhà Sản Xuất
  • Công ty : GlaxoSmithKline
    Sản phẩm biệt dược : Eltroxin
  • Công ty : Merck
    Sản phẩm biệt dược : Euthyrox
  • Công ty : Merck
    Sản phẩm biệt dược : Eutirox
  • Công ty : Berlin-Chemie
    Sản phẩm biệt dược : Letrox
  • Công ty : Nycomed
    Sản phẩm biệt dược : Levaxin
  • Công ty : Forest
    Sản phẩm biệt dược : Levothroid
  • Công ty : Merck
    Sản phẩm biệt dược : Levothyrox
  • Công ty : Jones
    Sản phẩm biệt dược : Levoxyl
  • Công ty :
    Sản phẩm biệt dược : Novothyrox
  • Công ty : GlaxoSmithKline
    Sản phẩm biệt dược : Oroxine
  • Công ty : Abbott
    Sản phẩm biệt dược : Synthroid
  • Công ty : Merck
    Sản phẩm biệt dược : Thyrax
  • Công ty : IBSA
    Sản phẩm biệt dược : Tirosint
  • Công ty : Watson
    Sản phẩm biệt dược : Unithroid
Đóng gói
Tài Liệu Tham Khảo Thêm
drugbank
http://www.drugbank.ca/drugs/DB00451
PubChem Compound
http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=5819
PubChem Substance
http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=46507672
KEGG Compound
http://www.genome.jp/dbget-bin/www_bget?cpd:C01829
ChemSpider
http://www.chemspider.com/Chemical-Structure.5614.html
National Drug Code Directory
http://www.hipaaspace.com/Medical_Billing/Coding/National.Drug.Codes/PDF/0781-5180-01
PharmGKB
http://www.pharmgkb.org/drug/PA450221
Wikipedia
http://en.wikipedia.org/wiki/Levothyroxine
RxList
http://www.rxlist.com/cgi/generic/levothy.htm
PDRhealth
http://www.pdrhealth.com/drug_info/rxdrugprofiles/drugs/syn1421.shtml
Drugs.com
http://www.drugs.com/levothyroxine.html
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