Tìm theo
Letrozole
Các tên gọi khác (3) :
  • Femara
  • Letrozol
  • Letrozole
Thuốc chống ung thư và tác động vào hệ thống miễn dịch
Thuốc Gốc
Small Molecule
CAS: 112809-51-5
ATC: L02BG04
ĐG : Kaiser Foundation Hospital
CTHH: C17H11N5
PTK: 285.3027
Letrozole (INN, trade name Femara®) is an oral non-steroidal aromatase inhibitor that has been introduced for the adjuvant treatment of hormonally-responsive breast cancer Estrogens are produced by the conversion of androgens through the activity of the aromatase enzyme. Letrozole blocks production of estrogens in this way by competitive, reversible binding to the heme of its cytochrome P450 unit. The action is specific, and letrozole does not reduce production of mineralo- or corticosteroids. In contrast, the antiestrogenic action of tamoxifen, the major medical therapy prior to the arrival of aromatase inhibitors, is due to its interfering with the estrogen receptor, rather than inhibiting estrogen production. Letrozole is approved by the United States Food and Drug Administration (FDA) for the treatment of local or metastatic breast cancer that is hormone receptor positive or has an unknown receptor status in postmenopausal women. Side effects include signs and symptoms of hypoestrogenism. There is concern that long term use may lead to osteoporosis, which is why prescriptions of Letrozole are often accompanied by prescriptions of osteoporosis-fighting medication such as Fosamax. Letrozole has shown to reduce estrogen levels by 98 percent while raising testosterone levels. The anti-estrogen action of letrozole is preferred by athletes and bodybuilders for use during a steroid cycle to reduce bloating due to excess water retention and prevent the formation of gynecomastia related breast tissue that is a side effect of some anabolic steroids. Usage above 2.5 mg/day is known to potentially temporarily kill sex drive. Above 5mg/day for extended periods may cause kidney problems. Letrozole has also been shown to delay the fusing of the growth plates in adolescents. This may boost the effectiveness of growth hormone, and thus Letrozole is used to treat adolescents and children with short stature.
Nhận Dạng Quốc Tế & Đặc Tính Hóa Học
Công thức hóa học
C17H11N5
Phân tử khối
285.3027
Monoisotopic mass
285.101445377
InChI
InChI=1S/C17H11N5/c18-9-13-1-5-15(6-2-13)17(22-12-20-11-21-22)16-7-3-14(10-19)4-8-16/h1-8,11-12,17H
InChI Key
InChIKey=HPJKCIUCZWXJDR-UHFFFAOYSA-N
IUPAC Name
4-[(4-cyanophenyl)(1H-1,2,4-triazol-1-yl)methyl]benzonitrile
Traditional IUPAC Name
letrozole
SMILES
N#CC1=CC=C(C=C1)C(N1C=NC=N1)C1=CC=C(C=C1)C#N
Độ tan chảy
184-185 °C
Độ hòa tan
7.99e-02 g/l
logP
2.5
logS
-3.5
pKa (Strongest Basic)
2.17
PSA
78.29 Å2
Refractivity
94.47 m3·mol-1
Polarizability
29.59 Å3
Rotatable Bond Count
3
H Bond Acceptor Count
4
H Bond Donor Count
0
Physiological Charge
0
Number of Rings
3
Bioavailability
1
Rule of Five
true
Ghose Filter
true
Dược Lực Học : Letrozole is an aromatase inhibitor used in the treatment of breast cancer. Aromatase inhibitors work by inhibiting the action of the enzyme aromatase, which converts androgens into estrogens by a process called aromatization. As breast tissue is stimulated by estrogens, decreasing their production is a way of suppressing recurrence of the breast tumor tissue.
Cơ Chế Tác Dụng : Letrozole (INN, trade name Femara®) is an oral non-steroidal aromatase inhibitor that has been introduced for the adjuvant treatment of hormonally-responsive breast cancer Estrogens are produced by the conversion of androgens through the activity of the aromatase enzyme. Letrozole blocks production of estrogens in this way by competitive, reversible binding to the heme of its cytochrome P450 unit. The action is specific, and letrozole does not reduce production of mineralo- or corticosteroids. In contrast, the antiestrogenic action of tamoxifen, the major medical therapy prior to the arrival of aromatase inhibitors, is due to its interfering with the estrogen receptor, rather than inhibiting estrogen production. Letrozole is approved by the United States Food and Drug Administration (FDA) for the treatment of local or metastatic breast cancer that is hormone receptor positive or has an unknown receptor status in postmenopausal women. Side effects include signs and symptoms of hypoestrogenism. There is concern that long term use may lead to osteoporosis, which is why prescriptions of Letrozole are often accompanied by prescriptions of osteoporosis-fighting medication such as Fosamax. Letrozole has shown to reduce estrogen levels by 98 percent while raising testosterone levels. The anti-estrogen action of letrozole is preferred by athletes and bodybuilders for use during a steroid cycle to reduce bloating due to excess water retention and prevent the formation of gynecomastia related breast tissue that is a side effect of some anabolic steroids. Usage above 2.5 mg/day is known to potentially temporarily kill sex drive. Above 5mg/day for extended periods may cause kidney problems. Letrozole has also been shown to delay the fusing of the growth plates in adolescents. This may boost the effectiveness of growth hormone, and thus Letrozole is used to treat adolescents and children with short stature. Letrozole is a nonsteroidal competitive inhibitor of the aromatase enzyme system; it inhibits the conversion of androgens to estrogens. In adult nontumor- and tumorbearing female animals, letrozole is as effective as ovariectomy in reducing uterine weight, elevating serum Leuteinizing hormone (LH), and causing the regression of estrogen-dependent tumors. In contrast to ovariectomy, treatment with letrozole does not lead to an increase in serum (folicile stimulating hormone (FSH). Letrozole selectively inhibits gonadal steroidogenesis but has no significant effect on adrenal mineralocorticoid or glucocorticoid synthesis.
Dược Động Học :
▧ Absorption :
Rapidly and completely absorbed. Absorption is not affected by food.
▧ Metabolism :
Primarily hepatic via CYP3A4 and CYP2A6. Letrozole inhibits the aromatase enzyme by competitively binding to the heme of the cytochrome P450 subunit of the enzyme, resulting in a reduction of estrogen biosynthesis in all tissues. It is metabolized slowly to an inactive metabolite whose glucuronide conjugate is excreted renally, representing the major clearance pathway.
▧ Half Life :
2 days
Chỉ Định : For the extended adjuvant treatment of early breast cancer in postmenopausal women who have received 5 years of adjuvant tamoxifen therapy. Also for first-line treatment of postmenopausal women with hormone receptor positive or hormone receptor unknown locally advanced or metastatic breast cancer. Also indicated for the treatment of advanced breast cancer in postmenopausal women with disease progression following antiestrogen therapy.
Liều Lượng & Cách Dùng : Tablet - Oral
Dữ Kiện Thương Mại
Giá thị trường
  • Biệt dược thương mại : Femara 2.5 mg tablet
    Giá bán buôn : USD >16.87
    Đơn vị tính : tablet
Nhà Sản Xuất
  • Công ty :
    Sản phẩm biệt dược : Femara
Đóng gói
Tài Liệu Tham Khảo Thêm
drugbank
http://www.drugbank.ca/drugs/DB01006
PubChem Compound
http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=3902
PubChem Substance
http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=46504610
KEGG Compound
http://www.genome.jp/dbget-bin/www_bget?cpd:C08163
KEGG Drug
http://www.genome.jp/dbget-bin/www_bget?drug:D00964
ChemSpider
http://www.chemspider.com/Chemical-Structure.3765.html
BindingDB
http://www.bindingdb.org/bind/chemsearch/marvin/MolStructure.jsp?monomerid=13061
PharmGKB
http://www.pharmgkb.org/drug/PA450196
Wikipedia
http://en.wikipedia.org/wiki/Letrozole
RxList
http://www.rxlist.com/cgi/generic2/letroz.htm
Drugs.com
http://www.drugs.com/cdi/letrozole.html
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