U.S. Department of Health & Human Services Divider Arrow National Institutes of Health Divider Arrow NCATS

Details

Stereochemistry ACHIRAL
Molecular Formula C17H11N5
Molecular Weight 285.3027
Optical Activity NONE
Defined Stereocenters 0 / 0
E/Z Centers 0
Charge 0

SHOW SMILES / InChI
Structure of LETROZOLE

SMILES

N#CC1=CC=C(C=C1)C(N2C=NC=N2)C3=CC=C(C=C3)C#N

InChI

InChIKey=HPJKCIUCZWXJDR-UHFFFAOYSA-N
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

HIDE SMILES / InChI

Molecular Formula C17H11N5
Molecular Weight 285.3027
Charge 0
Count
Stereochemistry ACHIRAL
Additional Stereochemistry No
Defined Stereocenters 0 / 0
E/Z Centers 0
Optical Activity NONE

Description
Curator's Comment: description was created based on several sources, including https://www.ncbi.nlm.nih.gov/pubmed/?term=17912632

Letrozole (trade name Femara), a nonsteroidal aromatase inhibitor. Femara is indicated for the adjuvant treatment of postmenopausal women with hormone receptor positive early breast cancer. Also is indicated for the extended adjuvant treatment of early breast cancer in postmenopausal women, who have received 5 years of adjuvant tamoxifen therapy. Femara has to be used for first-line treatment of postmenopausal women with hormone receptor positive or unknown, locally advanced or metastatic breast cancer and for the treatment of advanced breast cancer in postmenopausal women with disease progression following antiestrogen therapy. Treatment of breast cancer thought to be hormonally responsive (i.e., estrogen and/or progesterone receptor positive or receptor unknown) has included a variety of efforts to decrease estrogen levels (ovariectomy, adrenalectomy, hypophysectomy) or inhibit estrogen effects (antiestrogens and progestational agents). These interventions lead to decreased tumor mass or delayed progression of tumor growth in some women. In postmenopausal women, estrogens are mainly derived from the action of the aromatase enzyme, which converts adrenal androgens (primarily androstenedione and testosterone) to estrone and estradiol. The suppression of estrogen biosynthesis in peripheral tissues and in the cancer tissue itself can therefore be achieved by specifically inhibiting the aromatase enzyme. Letrozole inhibits the conversion of androgens to estrogens. Letrozole selectively inhibits gonadal steroidogenesis but has no significant effect on adrenal mineralocorticoid or glucocorticoid synthesis. 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. Treatment of women with letrozole significantly lowers serum estrone, estradiol and estrone sulfate and has not been shown to significantly affect adrenal corticosteroid synthesis, aldosterone synthesis, or synthesis of thyroid hormones. Letrozole is rapidly and completely absorbed from the gastrointestinal tract and absorption is not affected by food. Metabolism to a pharmacologically inactive carbinol metabolite (4,4'¬ methanol-bisbenzonitrile) and renal excretion of the glucuronide conjugate of this metabolite is the major pathway of letrozole clearance. In human microsomes with specific CYP isozyme activity, CYP3A4 metabolized letrozole to the carbinol metabolite while CYP2A6 formed both this metabolite and its ketone analog. In human liver microsomes, letrozole strongly inhibited CYP2A6 and moderately inhibited CYP2C19. The most common side effects are sweating, hot flashes, arthralgia (joint pain), and fatigue

Originator

Approval Year

Targets

Targets

Primary TargetPharmacologyConditionPotency
7.27 nM [IC50]
Conditions

Conditions

ConditionModalityTargetsHighest PhaseProduct
Primary
FEMARA

Approved Use

1.1 Adjuvant Treatment of Early Breast Cancer Letrozole tablets are indicated for the adjuvant treatment of postmenopausal women with hormone receptor positive early breast cancer. 1.2 Extended Adjuvant Treatment of Early Breast Cancer Letrozole tablets are indicated for the extended adjuvant treatment of early breast cancer in postmenopausal women, who have received 5 years of adjuvant tamoxifen therapy. The effectiveness of letrozole tablets in extended adjuvant treatment of early breast cancer is based on an analysis of disease-free survival in patients treated with letrozole tablets for a median of 60 months [see Clinical Studies (14.2, 14.3)

Launch Date

1997
Cmax

Cmax

ValueDoseCo-administeredAnalytePopulation
128 nM
2.5 mg single, oral
dose: 2.5 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
LETROZOLE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: FEMALE
food status: UNKNOWN
AUC

AUC

ValueDoseCo-administeredAnalytePopulation
4.26 μM × h
2.5 mg single, oral
dose: 2.5 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
LETROZOLE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: FEMALE
food status: UNKNOWN
T1/2

T1/2

ValueDoseCo-administeredAnalytePopulation
41.9 h
2.5 mg single, oral
dose: 2.5 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
LETROZOLE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: FEMALE
food status: UNKNOWN
Doses

Doses

DosePopulationAdverse events​
30 mg 1 times / day single, oral
Highest studied dose
Dose: 30 mg, 1 times / day
Route: oral
Route: single
Dose: 30 mg, 1 times / day
Sources:
healthy, Mean age 28.4 years
n = 3
Health Status: healthy
Age Group: Mean age 28.4 years
Sex: M
Population Size: 3
Sources:
2.5 mg 1 times / day multiple, oral
Recommended
Dose: 2.5 mg, 1 times / day
Route: oral
Route: multiple
Dose: 2.5 mg, 1 times / day
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P4.PDF - p.10
unhealthy, Mean age 63.6 years
n = 174
Health Status: unhealthy
Condition: breast cancer
Age Group: Mean age 63.6 years
Sex: F
Population Size: 174
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P4.PDF - p.10
Other AEs: Bilirubin abnormal, Aspartate aminotransferase abnormal...
Other AEs:
Bilirubin abnormal (grade 3, 5%)
Aspartate aminotransferase abnormal (grade 3, 3%)
ALT increased (grade 3, 3%)
Gamma-glutamyltransferase increased (grade 3, 6%)
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P4.PDF - p.10
2.5 mg 1 times / day multiple, oral
Recommended
Dose: 2.5 mg, 1 times / day
Route: oral
Route: multiple
Dose: 2.5 mg, 1 times / day
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P5.PDF - p.40
unhealthy, Mean age 66 years
n = 185
Health Status: unhealthy
Condition: breast cancer
Age Group: Mean age 66 years
Sex: F
Population Size: 185
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P5.PDF - p.40
Disc. AE: Hypercalcemia, Cerebrovascular accident...
Other AEs: Bilirubin abnormal, Aspartate aminotransferase abnormal...
AEs leading to
discontinuation/dose reduction:
Hypercalcemia
Cerebrovascular accident
Other AEs:
Bilirubin abnormal (grade 3, 3%)
Aspartate aminotransferase abnormal (grade 3, 4%)
ALT increased (grade 3, 1%)
Gamma-glutamyltransferase increased (grade 3, 9%)
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P5.PDF - p.40
10 mg 1 times / day multiple, oral
Highest studied dose
Dose: 10 mg, 1 times / day
Route: oral
Route: multiple
Dose: 10 mg, 1 times / day
Sources:
unhealthy, Mean age 71.6 years
n = 12
Health Status: unhealthy
Condition: breast cancer
Age Group: Mean age 71.6 years
Sex: F
Population Size: 12
Sources:
62.5 mg 1 times / day single, oral
Studied dose
Dose: 62.5 mg, 1 times / day
Route: oral
Route: single
Dose: 62.5 mg, 1 times / day
Sources:
unknown
n = 1
AEs

AEs

AESignificanceDosePopulation
ALT increased grade 3, 3%
2.5 mg 1 times / day multiple, oral
Recommended
Dose: 2.5 mg, 1 times / day
Route: oral
Route: multiple
Dose: 2.5 mg, 1 times / day
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P4.PDF - p.10
unhealthy, Mean age 63.6 years
n = 174
Health Status: unhealthy
Condition: breast cancer
Age Group: Mean age 63.6 years
Sex: F
Population Size: 174
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P4.PDF - p.10
Aspartate aminotransferase abnormal grade 3, 3%
2.5 mg 1 times / day multiple, oral
Recommended
Dose: 2.5 mg, 1 times / day
Route: oral
Route: multiple
Dose: 2.5 mg, 1 times / day
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P4.PDF - p.10
unhealthy, Mean age 63.6 years
n = 174
Health Status: unhealthy
Condition: breast cancer
Age Group: Mean age 63.6 years
Sex: F
Population Size: 174
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P4.PDF - p.10
Bilirubin abnormal grade 3, 5%
2.5 mg 1 times / day multiple, oral
Recommended
Dose: 2.5 mg, 1 times / day
Route: oral
Route: multiple
Dose: 2.5 mg, 1 times / day
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P4.PDF - p.10
unhealthy, Mean age 63.6 years
n = 174
Health Status: unhealthy
Condition: breast cancer
Age Group: Mean age 63.6 years
Sex: F
Population Size: 174
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P4.PDF - p.10
Gamma-glutamyltransferase increased grade 3, 6%
2.5 mg 1 times / day multiple, oral
Recommended
Dose: 2.5 mg, 1 times / day
Route: oral
Route: multiple
Dose: 2.5 mg, 1 times / day
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P4.PDF - p.10
unhealthy, Mean age 63.6 years
n = 174
Health Status: unhealthy
Condition: breast cancer
Age Group: Mean age 63.6 years
Sex: F
Population Size: 174
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P4.PDF - p.10
Cerebrovascular accident Disc. AE
2.5 mg 1 times / day multiple, oral
Recommended
Dose: 2.5 mg, 1 times / day
Route: oral
Route: multiple
Dose: 2.5 mg, 1 times / day
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P5.PDF - p.40
unhealthy, Mean age 66 years
n = 185
Health Status: unhealthy
Condition: breast cancer
Age Group: Mean age 66 years
Sex: F
Population Size: 185
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P5.PDF - p.40
Hypercalcemia Disc. AE
2.5 mg 1 times / day multiple, oral
Recommended
Dose: 2.5 mg, 1 times / day
Route: oral
Route: multiple
Dose: 2.5 mg, 1 times / day
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P5.PDF - p.40
unhealthy, Mean age 66 years
n = 185
Health Status: unhealthy
Condition: breast cancer
Age Group: Mean age 66 years
Sex: F
Population Size: 185
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P5.PDF - p.40
ALT increased grade 3, 1%
2.5 mg 1 times / day multiple, oral
Recommended
Dose: 2.5 mg, 1 times / day
Route: oral
Route: multiple
Dose: 2.5 mg, 1 times / day
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P5.PDF - p.40
unhealthy, Mean age 66 years
n = 185
Health Status: unhealthy
Condition: breast cancer
Age Group: Mean age 66 years
Sex: F
Population Size: 185
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P5.PDF - p.40
Bilirubin abnormal grade 3, 3%
2.5 mg 1 times / day multiple, oral
Recommended
Dose: 2.5 mg, 1 times / day
Route: oral
Route: multiple
Dose: 2.5 mg, 1 times / day
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P5.PDF - p.40
unhealthy, Mean age 66 years
n = 185
Health Status: unhealthy
Condition: breast cancer
Age Group: Mean age 66 years
Sex: F
Population Size: 185
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P5.PDF - p.40
Aspartate aminotransferase abnormal grade 3, 4%
2.5 mg 1 times / day multiple, oral
Recommended
Dose: 2.5 mg, 1 times / day
Route: oral
Route: multiple
Dose: 2.5 mg, 1 times / day
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P5.PDF - p.40
unhealthy, Mean age 66 years
n = 185
Health Status: unhealthy
Condition: breast cancer
Age Group: Mean age 66 years
Sex: F
Population Size: 185
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P5.PDF - p.40
Gamma-glutamyltransferase increased grade 3, 9%
2.5 mg 1 times / day multiple, oral
Recommended
Dose: 2.5 mg, 1 times / day
Route: oral
Route: multiple
Dose: 2.5 mg, 1 times / day
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P5.PDF - p.40
unhealthy, Mean age 66 years
n = 185
Health Status: unhealthy
Condition: breast cancer
Age Group: Mean age 66 years
Sex: F
Population Size: 185
Sources: Page: 20726_FEMARA%202.5MG_MEDR_P5.PDF - p.40
Overview

Overview

CYP3A4CYP2C9CYP2D6hERG



Drug as perpetrator​Drug as victim

Drug as victim

TargetModalityActivityMetaboliteClinical evidence
no
no
no
no
no
no
no
no
no
no
yes
yes (co-administration study)
Comment: The effect of a 400 mg b.i.d treatment with cimetidine for 7 days on the letrozole pharmacokinetics after a single 2.5-mg dose was investigated in 16 healthy subjects [Protocol 004], A slight but statistically significant decrease in systemic exposure and an increase in Cmax were observed when letrozole was administered together with cimetidine (table below).
Page: 4.0
yes
yes (co-administration study)
Comment: The effect of a 400 mg b.i.d treatment with cimetidine for 7 days on the letrozole pharmacokinetics after a single 2.5-mg dose was investigated in 16 healthy subjects [Protocol 004], A slight but statistically significant decrease in systemic exposure and an increase in Cmax were observed when letrozole was administered together with cimetidine (table below).
Page: 4.0
PubMed

PubMed

TitleDatePubMed
Aromatase inhibitors.
2001
Aromatase and aromatase inhibitors.
2001
[Neoadjuvant use of the aromatase inhibitor letrozole in uterine cancer: endocrine and clinical effects].
2001
Metastatic breast cancer: understanding current management options.
2001 Apr
Developmental regulation of morphological differentiation of placental villous trophoblast in the baboon.
2001 Apr
Flare and tumor lysis syndrome with atypical features after letrozole therapy in advanced breast cancer. A case report.
2001 Apr-Jun
Promising results for Arimidex and Femara.
2001 Dec
Future use of selective estrogen receptor modulators and aromatase inhibitors.
2001 Dec
Neoadjuvant endocrine therapy for breast cancer: medical perspectives.
2001 Dec
The role of tamoxifen and aromatase inhibitors/inactivators in postmenopausal patients.
2001 Dec
Comparative clinical pharmacology and pharmacokinetic interactions of aromatase inhibitors.
2001 Dec
Aromatase and COX-2 expression in human breast cancers.
2001 Dec
Aromatase overexpression transgenic mice model: cell type specific expression and use of letrozole to abrogate mammary hyperplasia without affecting normal physiology.
2001 Dec
FDA panel recommends two new cancer drugs for approval.
2001 Feb 7
Intracellular aromatase and its relevance to the pharmacological efficacy of aromatase inhibitors.
2001 Jan-Mar
Endocrine therapy in the treatment of metastatic breast cancer.
2001 Jun
A specific aromatase inhibitor and potential increase in adult height in boys with delayed puberty: a randomised controlled trial.
2001 Jun 2
Femara approved as first-line breast cancer therapy.
2001 May-Jun
Formestane, a steroidal aromatase inhibitor after failure of non-steroidal aromatase inhibitors (anastrozole and letrozole): is a clinical benefit still achievable?
2001 Nov
Preoperative treatment of postmenopausal breast cancer patients with letrozole: A randomized double-blind multicenter study.
2001 Nov
Pre-operative endocrine therapy for postmenopausal women: when and why?
2001 Nov
Developmental maturation of primate placental trophoblast: placental cytosolic and secretory phospholipase A2 expression after estrogen suppression of baboons.
2001 Oct
Aromatase inhibitors: treatment of advanced breast cancer.
2001 Oct 1
Advances in aromatase inhibition: clinical efficacy and tolerability in the treatment of breast cancer.
2001 Sep
Use of ErbB-1 and ErbB-2 to select endocrine therapy for breast cancer: will it play in Peoria?
2001 Sep 15
Defining the galaxy of gene expression in breast cancer.
2002
Estrogen as therapy for breast cancer.
2002
Novel treatment of delayed male puberty with aromatase inhibitors.
2002
Recent advances in breast cancer (the Twenty-fourth San Antonio Breast Cancer Symposium, December, 2001).
2002
Tamoxifen resistant and refractory breast cancer: the value of aromatase inhibitors.
2002
Antiaromatase agents: evolving role in adjuvant therapy.
2002 Apr
Short-term effects of anastrozole treatment on insulin-like growth factor system in postmenopausal advanced breast cancer patients.
2002 Apr
[CGS 20267 (Letrozole), a new aromatase inhibitor: early phase II study for postmenopausal women with advanced breast cancer].
2002 Apr
New breast cancer drugs expand treatment options.
2002 Apr
Aromatase inhibition improves ovarian response to follicle-stimulating hormone in poor responders.
2002 Apr
[Superiority of letrozole compared with tamoxifen as first line therapy of postmenopausal women with advanced breast cancer: results of a phase III study of the International Letrozole Breast Cancer Group].
2002 Feb
Superior efficacy of letrozole versus tamoxifen as first-line therapy.
2002 Feb 1
Influence of letrozole and anastrozole on total body aromatization and plasma estrogen levels in postmenopausal breast cancer patients evaluated in a randomized, cross-over study.
2002 Feb 1
Genetic or enzymatic disruption of aromatase inhibits the growth of ectopic uterine tissue.
2002 Jul
Human ejaculated spermatozoa contain active P450 aromatase.
2002 Jul
Effects of the aromatase inhibitor letrozole on normal breast epithelial cell proliferation and metabolic indices in postmenopausal women: a pilot study for breast cancer prevention.
2002 Jul
Endocrine effects of nonsteroidal aromatase inhibitors and their clinical impact.
2002 Jul 1
Exemestane: a potent irreversible aromatase inactivator and a promising advance in breast cancer treatment.
2002 Jun
Letrozole for the management of breast cancer.
2002 Jun
Approval summary: letrozole in the treatment of postmenopausal women with advanced breast cancer.
2002 Mar
Aromatase inhibitors in breast cancer.
2002 Mar
Endocrine and clinical endpoints of exemestane as neoadjuvant therapy.
2002 Mar-Apr
Anti-aromatase agents in the treatment and prevention of breast cancer.
2002 Mar-Apr
[CGS20267 (Letrozole), a new aromatase inhibitor: late phase II study for postmenopausal women with advanced or recurrent breast cancer (no. 1)--investigation of recommended clinical dose CGS20267 Study Group].
2002 May
Letrozole in the treatment of breast cancer.
2002 May
Patents

Sample Use Guides

The recommended dose of Femara (letrozole) is one 2.5 mg tablet administered once a day, without regard to meals.
Route of Administration: Oral
After treatment of cells with letrozole (10 nM) for 24 and 48 h, significant inhibition of matrix metalloproteinases (MMP) levels was obtained. Furthermore, concurrent treatment of MCF-7, human epithelial breast cancer cells with 17-beta-estradiol in the presence of letrozole significantly suppressed the estradiol-induced stimulation of MMP levels. Letrozole is a potent in vitro inhibitor of cell proliferation and of type IV collagenases expressed by estrogen receptor (ER)-positive MCF-7 cells and may be of value for suppressing breast tumor growth and invasiveness.
Substance Class Chemical
Created
by admin
on Fri Dec 15 15:41:46 GMT 2023
Edited
by admin
on Fri Dec 15 15:41:46 GMT 2023
Record UNII
7LKK855W8I
Record Status Validated (UNII)
Record Version
  • Download
Name Type Language
LETROZOLE
EP   HSDB   INN   JAN   MART.   MI   ORANGE BOOK   USAN   USP   USP-RS   VANDF   WHO-DD  
USAN   INN  
Official Name English
CGS 20267
Code English
4,4'-(1H-1,2,4-TRIAZOL-1-YLMETHYLENE)DIBENZONITRILE
Systematic Name English
LETROZOLE [ORANGE BOOK]
Common Name English
LETROZOLE [USP MONOGRAPH]
Common Name English
LETROZOLE [USAN]
Common Name English
FEMARA
Brand Name English
CGS-20267
Code English
LETROZOLE COMPONENT OF KISQALI FEMARA CO-PACK
Brand Name English
KISQALI FEMARA CO-PACK COMPONENT LETROZOLE
Brand Name English
LETROZOLE [MART.]
Common Name English
LETROZOLE [USP-RS]
Common Name English
LETROZOLE [MI]
Common Name English
LETROZOLE [JAN]
Common Name English
LETROZOLE [EP IMPURITY]
Common Name English
LETROZOLE [EP MONOGRAPH]
Common Name English
Letrozole [WHO-DD]
Common Name English
BENZONITRILE, 4,4'-(1H-1,2,4-TRIAZOL-1-YLMETHYLENE)BIS-
Systematic Name English
NSC-759652
Code English
letrozole [INN]
Common Name English
LETROZOLE [HSDB]
Common Name English
Classification Tree Code System Code
LIVERTOX NBK548381
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
WHO-VATC QL02BG04
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
NDF-RT N0000175563
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
WHO-ATC L02BG04
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
NDF-RT N0000175080
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
NCI_THESAURUS C2018
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
Code System Code Type Description
MERCK INDEX
m6772
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
PRIMARY Merck Index
ChEMBL
CHEMBL1444
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PRIMARY
NCI_THESAURUS
C1527
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
PRIMARY
RXCUI
72965
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
PRIMARY RxNorm
IUPHAR
5209
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PRIMARY
USAN
EE-48
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PRIMARY
DRUG CENTRAL
1556
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PRIMARY
DRUG BANK
DB01006
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PRIMARY
CAS
112809-51-5
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
PRIMARY
CHEBI
6413
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
PRIMARY
MESH
C067431
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PRIMARY
SMS_ID
100000092486
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
PRIMARY
FDA UNII
7LKK855W8I
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
PRIMARY
EPA CompTox
DTXSID4023202
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
PRIMARY
WIKIPEDIA
LETROZOLE
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
PRIMARY
HSDB
7461
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
PRIMARY
DAILYMED
7LKK855W8I
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
PRIMARY
PUBCHEM
3902
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
PRIMARY
EVMPD
SUB08444MIG
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
PRIMARY
RS_ITEM_NUM
1356971
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
PRIMARY
LACTMED
Letrozole
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
PRIMARY
NSC
759652
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
PRIMARY
INN
7118
Created by admin on Fri Dec 15 15:41:46 GMT 2023 , Edited by admin on Fri Dec 15 15:41:46 GMT 2023
PRIMARY
Related Record Type Details
BASIS OF STRENGTH->SUBSTANCE
ASSAY (HPLC)
EP
METABOLIC ENZYME -> SUBSTRATE
BASIS OF STRENGTH->SUBSTANCE
CHROMATOGRAPHIC PURITY (HPLC/UV)
USP
METABOLIC ENZYME -> SUBSTRATE
METABOLIC ENZYME -> SUBSTRATE
TARGET -> INHIBITOR
Competitive inhibitor of the aromatase enzyme system; it inhibits the conversion of androgens to estrogens. 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.
Related Record Type Details
METABOLITE -> PARENT
MAJOR
URINE
Related Record Type Details
IMPURITY -> PARENT
CHROMATOGRAPHIC PURITY (HPLC/UV)
USP
IMPURITY -> PARENT
CHROMATOGRAPHIC PURITY (HPLC/UV)
EP
IMPURITY -> PARENT
CHROMATOGRAPHIC PURITY (HPLC/UV)
USP
IMPURITY -> PARENT
CHROMATOGRAPHIC PURITY (HPLC/UV)
EP
Related Record Type Details
ACTIVE MOIETY
Name Property Type Amount Referenced Substance Defining Parameters References
Volume of Distribution PHARMACOKINETIC