What are the medical uses of tamoxifen


Synonym: (Z) -2- [4- (1,2-Diphenylbut-1-enyl) phenoxy] -N, N-dimethylethylamine
Trade name: Ebefen®, Mandofen®, Nolvadex® i.a.

1 definition

Tamoxifen is a drug that belongs to the selective estrogen receptor modulators (SERM) and is mainly used to treat breast cancer.

2 chemistry

Tamoxifen has the molecular formula C.26H29NO and a molar mass of 371.51 g mol-1. The melting point is 97 ° C.

3 Mechanism of Action

Tamoxifen blocks the cytoplasmic estrogen receptors via competitive inhibition, which leads to a reduction in cell division activity in estrogen-dependent tissues. The drug therefore acts as a cytostatic agent.

4 pharmacokinetics

The prodrug tamoxifen is mainly metabolized by CYP3A4 to N-desmethyl tamoxifen and then by CYP2D6 to 4-hydroxy-N-desmethyl tamoxifen (endoxifen) and thereby activated. The metabolites show an increased affinity for estrogen receptors compared to tamoxifen. If polymorphisms of the CYP-2D6 gene are present, the patient's response to tamoxifen therapy will therefore vary.

5 indication

Tamoxifen is used primarily for hormone-receptor-positive breast cancer as adjuvant therapy after primary therapy and for the treatment of metastatic breast cancer. Further areas of application are:

6 dosage form

Tamoxifen is administered orally in the form of film-coated tablets and tablets.

7 side effects

The following side effects have been associated with tamoxifen:

Reversible retinopathy or cataracts can rarely occur.

8 interactions

9 contraindication

The administration of tamoxifen is contraindicated in children, during pregnancy and in nursing mothers.

10 Regulation notice

Tamoxifen requires a prescription.

11 sources

  • Regierer, Anne C. / Bolbrinker, Juliane / Possinger, K .: Individualization of systemic therapy for breast cancer. In: Der Bayerische Internist 29 (2009). H.3, pp.141-144.
  • Shang Y1: Molecular mechanisms of estrogen and SERMs in endometrial carcinogenesis. Nat Rev Cancer. 2006 May; 6 (5): 360-8.
  • Shapiro, CL., Law, A .: Side effects of adjuvant treatment of breast cancer. N Engl J Med. 2001 Jun 28; 344 (26)