- Molecular NameLetrozole
- SynonymLetrozol; letrozole
- Weight285.31
- Drugbank_IDDB01006
- ACS_NO112809-51-5
- Show 2D model
- LogP (experiment)3.385
- LogP (predicted, AB/LogP v2.0)2.5
- pkaN/A
- LogD (pH=7, predicted)2.5
- Solubility (experiment)N/A
- LogS (predicted, ACD/Labs)(ph=7)-4.56
- LogSw (predicted, AB/LogsW2.0)0.05
- Sw (mg/ml) (predicted, ACD/Labs)0.01
- No.of HBond Donors0
- No.of HBond Acceptors5
- No.of Rotatable Bonds5
- TPSA78.29
- StatusFDA approved
- AdministrationN/A
- PharmacologyAn oral non-steroidal aromatase inhibitor for the treatment of hormonally-responsive breast cancer after surgery.
- Absorption_value100.0
- Absorption (description)Letrozole is rapidly and completely absorbed after oral administration which can be affected by the presence of food. Peak concentrations tend to be larger when the drug is administered without food and these concentrations are reached in about half the time compared with individuals who are administered letrozole with food.
- Caco_2N/A
- Bioavailability100.0
- Protein binding60.0
- Volume of distribution (VD)1.87 L/kg
- Blood/Plasma Partitioning ratio (D_blood)The concentration of letrozole in erythrocytes is approx. 80% of that found in plasma.
- MetabollsmMetabolized by CYP3A4 and CYP2A6
- Half life45 h
- ExcretionApprox. 90% of the dose is excreted in urine; 75% as the glucuronide of the metabolite, 9% unidentified metabolites and 6% unchanged drug. Steady state plasma concentrations are reached within 2 to 6 weeks and remain constant over time without accumulation of the drug.
- Urinary Excretion3.9
- Clerance0.58 ml/min/kg
- ToxicityThe adverse events of Letrozole occured in more than 5% of breast cancer patients treated with Tamoxifen and Letrozole include Hot Flashes, Arthralgia/Arthritis, Night Sweats, Weight Increase, Nausea, Fatigue (Lethargy, Malaise, Asthenia), Edema, Myalgia, Bone Fractures.
- LD50 (rat)N/A
- LD50 (mouse)N/A