Adverse Drug Reaction Classification System

Pharmaceutical Information
Drug Name Letrozole
Drug ID BADD_D01257
Description Letrozole, or CGS 20267, is an oral non-steroidal type II aromatase inhibitor first described in the literature in 1990.[A190543,A1559,L11623,L11626] It is a third generation aromatase inhibitor like [exemestane] and [anastrozole], meaning it does not significantly affect cortisol, aldosterone, and thyroxine.[A190546] Letrozole was granted FDA approval on 25 July 1997.[L11623]
Indications and Usage Letrozole is indicated to treat postmenopausal women with hormone receptor (HR) positive early breast cancer, postmenopausal women with early breast cancer who have periviously been treated with tamoxifen, and postmenopausal women with HR+ or unknown advanced breast cancer.[L11623] Letrozole, given with ribociclib, is indicated to treat pre, peri, and postmenopausal women with HR+ and human epidermal growth factor 2 (HER2) negative advanced or metastatic breast cancer.[L11626]
Marketing Status approved; investigational
ATC Code L02BG04
DrugBank ID DB01006
KEGG ID D00964
MeSH ID D000077289
PubChem ID 3902
TTD Drug ID D0C1WH
NDC Product Code 58623-0099; 62135-491; 63629-7819; 71205-587; 69988-0014; 50268-476; 68554-0039; 16729-034; 51991-759; 59651-180; 63850-0025; 57884-0011; 65096-0116; 13808-514; 63592-3376; 65129-1130; 0078-0249; 55111-809; 63850-7723; 0093-7620; 42291-374; 71335-1526; 63850-7701; 55111-646
UNII 7LKK855W8I
Synonyms Letrozole | 4,4'-(1H-1,2,4-triazol-1-yl-methylene)-bis(benzonitrile) | CGS 20267 | CGS-20267 | CGS20267 | Femara | Fémara
Chemical Information
Molecular Formula C17H11N5
CAS Registry Number 112809-51-5
SMILES C1=CC(=CC=C1C#N)C(C2=CC=C(C=C2)C#N)N3C=NC=N3
Chemical Structure
ADRs Induced by Drug
*The priority for ADR severity classification is based on FAERS assessment, followed by the most severe level in CTCAE rating. If neither is available, it will be displayed as 'Not available'.
**The 'Not Available' level is hidden by default and can be restored by clicking on the legend twice..
ADR Term ADReCS ID ADR Frequency (FAERS) ADR Severity Grade (FAERS) ADR Severity Grade (CTCAE)
Pelvic mass21.07.04.012; 08.03.05.009; 07.11.01.0280.000527%Not Available
Portal shunt24.08.06.007; 09.01.06.0230.000659%Not Available
Recurrent cancer16.16.01.0150.000790%Not Available
Toxic nodular goitre14.11.01.047; 05.02.02.0070.000263%Not Available
Concomitant disease progression08.01.03.0640.000527%Not Available
Live birth18.08.02.0070.000263%Not Available
Metastases to abdominal wall16.22.02.011; 07.16.05.0070.000395%Not Available
Lymphangiosis carcinomatosa24.09.02.007; 16.22.02.009; 01.09.01.0270.000395%Not Available
Bone swelling15.02.01.0060.000263%Not Available
Breast cancer metastatic21.05.01.016; 16.10.01.0080.006322%Not Available
Tenosynovitis stenosans15.07.01.0130.000922%Not Available
Hepatic mass09.01.08.0150.000263%Not Available
Hand deformity15.10.03.0070.000896%Not Available
Malignant peritoneal neoplasm16.13.04.005; 07.21.03.0050.000263%Not Available
Myosclerosis15.05.03.0320.000263%Not Available
Nail growth abnormal23.02.05.0240.000790%Not Available
Gastric fistula12.02.03.018; 07.11.05.0110.000263%
Ovarian cancer recurrent21.11.01.014; 16.12.04.0050.000659%Not Available
Retroperitoneal lymphadenopathy07.07.01.012; 01.09.01.0290.000395%Not Available
Skin plaque23.03.03.0440.000395%Not Available
Overlap syndrome23.03.02.018; 15.06.01.016; 10.04.04.0160.000395%Not Available
Basal ganglia infarction24.04.06.028; 17.08.01.0400.000263%Not Available
Exposed bone in jaw15.02.04.0340.000527%Not Available
Spinal pain17.10.01.020; 15.02.01.008; 08.01.08.0300.000263%Not Available
Preterm premature rupture of membranes18.02.02.0160.000263%Not Available
Invasive ductal breast carcinoma21.05.01.021; 16.10.01.0130.000922%Not Available
Invasive lobular breast carcinoma21.05.01.022; 16.10.01.0140.000711%Not Available
Pulmonary pain22.12.01.0100.000263%Not Available
B-cell lymphoma stage III16.28.01.006; 01.15.01.0060.000527%Not Available
Blood loss anaemia24.07.01.088; 01.03.02.0180.000263%Not Available
The 19th Page    First    Pre   19 20    Next   Last    Total 20 Pages
ADReCS-Target
Drug Name ADR Term Target
Tip:  Drug Name  ADR Term  Protein  Variation  Gene