Peringatan Keamanan

Overdose data in humans is not readily available, however 1 reported case was not associated with serious adverse reactions.L11623 Animal studies do not report serious adverse effects with high dose treatment.A190564 Patients experiencing and overdose should be treated with symptomatic and supportive measures.L11623

Oral doses over 2000mg/kg were associated with reduced motor activity, ataxia, dyspnea, and death in mice and rats.L11623

Letrozole

DB01006

small molecule approved investigational

Deskripsi

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

Struktur Molekul 2D

Berat 285.3027
Wujud solid

Peta Jejaring Molekuler
Legenda: Obat • Target • Gen • Enzim • (Panah → menunjukkan arah efek / relasi) • Transporter • Carrier

Profil Farmakokinetik

Waktu Paruh (Half-Life) The terminal elimination half life of letrozole is approximately 42h in healthy volunteers, but longer in breast cancer patients.[A190546,A190555,L11623]
Volume Distribusi The volume of distribution of letrozole is 1.87L/kg.[A190546]
Klirens (Clearance) The average clearance after a single dose of letrozole was 1.52L/h and at steady state was 1.20L/h.[A190555]

Absorpsi

Letrozole is 99.9% orally bioavailable.A190546 A 2.5mg oral dose reaches a Cmax of 104nmol/L with a Tmax of 8.10h, and an AUC of 7387nmol\*h/L.A190555

Metabolisme

Letrozole is metabolized by CYP2A6 to a ketone analog metabolite, which is further metabolized by CYP3A4 and CYP2A6 to 4,4'-(hydroxymethylene)dibenzonitrile.A33288 4,4'-(hydroxymethylene)dibenzonitrile is glucuronidated by UGT2B7.A190549

Rute Eliminasi

Letrozole is 90% eliminated in the urine.L11623 75% of the dose is recovered as a glucuronide metabolite, 9% is in the form of the ketone and carbinol metabolites, and 6% is recovered in urine as unchanged letrozole.A33288,L11623

Interaksi Makanan

1 Data
  • 1. Take with or without food. Food slows absorption without decreasing the quantity absorbed.

Interaksi Obat

374 Data
Cilostazol The serum concentration of Cilostazol can be increased when it is combined with Letrozole.
Tamoxifen The serum concentration of Letrozole can be decreased when it is combined with Tamoxifen.
Methadone The serum concentration of Methadone can be increased when it is combined with Letrozole.
Pentobarbital The metabolism of Letrozole can be increased when combined with Pentobarbital.
Tranylcypromine The metabolism of Letrozole can be decreased when combined with Tranylcypromine.
Nicotine The metabolism of Nicotine can be decreased when combined with Letrozole.
Nevirapine The metabolism of Nevirapine can be decreased when combined with Letrozole.
Valproic acid The metabolism of Valproic acid can be decreased when combined with Letrozole.
Acetaminophen The metabolism of Acetaminophen can be decreased when combined with Letrozole.
Chlorzoxazone The metabolism of Chlorzoxazone can be decreased when combined with Letrozole.
Clozapine The metabolism of Clozapine can be decreased when combined with Letrozole.
Montelukast The metabolism of Montelukast can be decreased when combined with Letrozole.
Zidovudine The metabolism of Zidovudine can be decreased when combined with Letrozole.
Cinnarizine The metabolism of Cinnarizine can be decreased when combined with Letrozole.
Flurazepam The metabolism of Flurazepam can be decreased when combined with Letrozole.
Metronidazole The metabolism of Metronidazole can be decreased when combined with Letrozole.
Formoterol The metabolism of Formoterol can be decreased when combined with Letrozole.
Methoxyflurane The metabolism of Methoxyflurane can be decreased when combined with Letrozole.
Selegiline The metabolism of Selegiline can be decreased when combined with Letrozole.
Nifedipine The metabolism of Nifedipine can be decreased when combined with Letrozole.
Halothane The metabolism of Halothane can be decreased when combined with Letrozole.
Ifosfamide The metabolism of Ifosfamide can be decreased when combined with Letrozole.
Sevoflurane The metabolism of Sevoflurane can be decreased when combined with Letrozole.
Arformoterol The metabolism of Arformoterol can be decreased when combined with Letrozole.
Antipyrine The metabolism of Antipyrine can be decreased when combined with Letrozole.
Flunitrazepam The metabolism of Flunitrazepam can be decreased when combined with Letrozole.
Phenacetin The metabolism of Phenacetin can be decreased when combined with Letrozole.
Flunarizine The metabolism of Flunarizine can be decreased when combined with Letrozole.
Lorcaserin The metabolism of Lorcaserin can be decreased when combined with Letrozole.
Clomethiazole The metabolism of Clomethiazole can be decreased when combined with Letrozole.
Vortioxetine The metabolism of Vortioxetine can be decreased when combined with Letrozole.
Propacetamol The metabolism of Propacetamol can be decreased when combined with Letrozole.
Tegafur-uracil The metabolism of Tegafur-uracil can be decreased when combined with Letrozole.
Asunaprevir The metabolism of Asunaprevir can be decreased when combined with Letrozole.
Miconazole The metabolism of Letrozole can be decreased when combined with Miconazole.
Azelastine The metabolism of Azelastine can be decreased when combined with Letrozole.
Plitidepsin The metabolism of Plitidepsin can be decreased when combined with Letrozole.
Cisapride The metabolism of Cisapride can be decreased when combined with Letrozole.
Phenytoin The metabolism of Letrozole can be increased when combined with Phenytoin.
Pitolisant The serum concentration of Letrozole can be decreased when it is combined with Pitolisant.
Metreleptin The metabolism of Letrozole can be increased when combined with Metreleptin.
Leuprolide The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Leuprolide is combined with Letrozole.
Somatotropin The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Somatotropin is combined with Letrozole.
Daptomycin The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Daptomycin is combined with Letrozole.
Pravastatin The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Pravastatin is combined with Letrozole.
Baclofen The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Baclofen is combined with Letrozole.
Cladribine The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Cladribine is combined with Letrozole.
Pamidronic acid The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Pamidronic acid is combined with Letrozole.
Mefloquine The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Mefloquine is combined with Letrozole.
Tacrine The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Tacrine is combined with Letrozole.
Carbimazole The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Carbimazole is combined with Letrozole.
Cerivastatin The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Cerivastatin is combined with Letrozole.
Trimethoprim The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Trimethoprim is combined with Letrozole.
Betamethasone The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Betamethasone is combined with Letrozole.
Cimetidine The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Cimetidine is combined with Letrozole.
Lercanidipine The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Lercanidipine is combined with Letrozole.
Ciprofloxacin The metabolism of Letrozole can be decreased when combined with Ciprofloxacin.
Vincristine The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Vincristine is combined with Letrozole.
Propylthiouracil The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Propylthiouracil is combined with Letrozole.
Methotrexate The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Methotrexate is combined with Letrozole.
Enalapril The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Enalapril is combined with Letrozole.
Nizatidine The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Nizatidine is combined with Letrozole.
Ivermectin The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Ivermectin is combined with Letrozole.
Chloroquine The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Chloroquine is combined with Letrozole.
Triamcinolone The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Triamcinolone is combined with Letrozole.
Niacin The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Niacin is combined with Letrozole.
Alendronic acid The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Alendronic acid is combined with Letrozole.
Clofibrate The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Clofibrate is combined with Letrozole.
Stavudine The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Stavudine is combined with Letrozole.
Nafarelin The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Nafarelin is combined with Letrozole.
Amphotericin B The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Amphotericin B is combined with Letrozole.
Mycophenolate mofetil The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Mycophenolate mofetil is combined with Letrozole.
Lamivudine The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Lamivudine is combined with Letrozole.
Ibandronate The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Ibandronate is combined with Letrozole.
Propofol The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Propofol is combined with Letrozole.
Terbinafine The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Terbinafine is combined with Letrozole.
Penicillamine The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Penicillamine is combined with Letrozole.
Ranitidine The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Ranitidine is combined with Letrozole.
Eprosartan The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Eprosartan is combined with Letrozole.
Risedronic acid The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Risedronic acid is combined with Letrozole.
Bumetanide The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Bumetanide is combined with Letrozole.
Ethanol The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Ethanol is combined with Letrozole.
Salmeterol The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Salmeterol is combined with Letrozole.
Isoniazid The metabolism of Letrozole can be decreased when combined with Isoniazid.
Methyldopa The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Methyldopa is combined with Letrozole.
Isotretinoin The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Isotretinoin is combined with Letrozole.
Cytarabine The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Cytarabine is combined with Letrozole.
Ganciclovir The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Ganciclovir is combined with Letrozole.
Sulfamethoxazole The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Letrozole is combined with Sulfamethoxazole.
Minocycline The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Letrozole is combined with Minocycline.
Procainamide The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Letrozole is combined with Procainamide.
Fenofibrate The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Letrozole is combined with Fenofibrate.
Norfloxacin The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Letrozole is combined with Norfloxacin.
Atorvastatin The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Letrozole is combined with Atorvastatin.
Fluvastatin The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Letrozole is combined with Fluvastatin.
Rosuvastatin The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Letrozole is combined with Rosuvastatin.
Ofloxacin The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Letrozole is combined with Ofloxacin.
Procarbazine The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Letrozole is combined with Procarbazine.
Captopril The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Letrozole is combined with Captopril.
Metoclopramide The risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Letrozole is combined with Metoclopramide.

Target Protein

Aromatase CYP19A1

Referensi & Sumber

Synthesis reference: Peter MacDonald, Ettore Bigatti, Pierluigi Rossetto, Zvi Harel, "Process for the preparation of letrozole." U.S. Patent US20070066831, issued March 22, 2007.
Artikel (PubMed)
  • PMID: 2149502
    Bhatnagar AS, Hausler A, Schieweck K, Lang M, Bowman R: Highly selective inhibition of estrogen biosynthesis by CGS 20267, a new non-steroidal aromatase inhibitor. J Steroid Biochem Mol Biol. 1990 Dec 20;37(6):1021-7. doi: 10.1016/0960-0760(90)90460-3.
  • PMID: 17912633
    Bhatnagar AS: The discovery and mechanism of action of letrozole. Breast Cancer Res Treat. 2007;105 Suppl 1:7-17. doi: 10.1007/s10549-007-9696-3. Epub 2007 Oct 3.
  • PMID: 23965986
    Precht JC, Schroth W, Klein K, Brauch H, Krynetskiy E, Schwab M, Murdter TE: The letrozole phase 1 metabolite carbinol as a novel probe drug for UGT2B7. Drug Metab Dispos. 2013 Nov;41(11):1906-13. doi: 10.1124/dmd.113.053405. Epub 2013 Aug 21.
  • PMID: 11745921
    Pfister CU, Martoni A, Zamagni C, Lelli G, De Braud F, Souppart C, Duval M, Hornberger U: Effect of age and single versus multiple dose pharmacokinetics of letrozole (Femara) in breast cancer patients. Biopharm Drug Dispos. 2001 Jul;22(5):191-7. doi: 10.1002/bdd.273.
  • PMID: 18728707
    Nabholtz JM: Long-term safety of aromatase inhibitors in the treatment of breast cancer. Ther Clin Risk Manag. 2008 Feb;4(1):189-204.
  • PMID: 8476774
    Schieweck K, Bhatnagar AS, Batzl C, Lang M: Anti-tumor and endocrine effects of non-steroidal aromatase inhibitors on estrogen-dependent rat mammary tumors. J Steroid Biochem Mol Biol. 1993 Mar;44(4-6):633-6. doi: 10.1016/0960-0760(93)90270-7.
  • PMID: 25695958
    Dave N, Chow LM, Gudelsky GA, LaSance K, Qi X, Desai PB: Preclinical pharmacological evaluation of letrozole as a novel treatment for gliomas. Mol Cancer Ther. 2015 Apr;14(4):857-64. doi: 10.1158/1535-7163.MCT-14-0743. Epub 2015 Feb 18.
  • PMID: 19198839
    Jeong S, Woo MM, Flockhart DA, Desta Z: Inhibition of drug metabolizing cytochrome P450s by the aromatase inhibitor drug letrozole and its major oxidative metabolite 4,4'-methanol-bisbenzonitrile in vitro. Cancer Chemother Pharmacol. 2009 Oct;64(5):867-75. doi: 10.1007/s00280-009-0935-7. Epub 2009 Feb 7.

Contoh Produk & Brand

Produk: 83 • International brands: 0
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