section name header

Pronunciation ⬇

ta-MOX-i-fen

Classifications ⬆ ⬇

Therapeutic Classification: antineoplastics

Pharmacologic Classification: antiestrogens

Indications ⬆ ⬇

High Alert

Action ⬆ ⬇

  • Competes with estrogen for binding sites in breast and other tissues.
  • Reduces DNA synthesis and estrogen response.
Therapeutic effects:
  • Suppression of tumor growth.
  • Reduced incidence of breast cancer in high-risk patients.

Pharmacokinetics ⬆ ⬇

Absorption: Well absorbed after oral administration.

Distribution: Widely distributed to tissues.

Metabolism/Excretion: Primarily metabolized by the liver via the CYP3A isoenzyme into N-desmethyltamoxifen and via the CYP2D6 isoenzyme into 4-hydroxytamoxifen. Both of these metabolites are further metabolized into endoxifen (N-desmethyltamoxifen via CYP2D6 and 4-hydroxytamoxifen via CYP3A). Both endoxifen and 4-hydroxytamoxifen are 30- to 100-fold more potent than tamoxifen in suppressing estrogen-dependent cell proliferation. The CYP2D6 enzyme system exhibits genetic polymorphism (∼7% of population may be poor metabolizers and may have significantly ↓ endoxifen concentrations and ↓ effectiveness of tamoxifen). Slowly eliminated in the feces. Minimal amounts excreted in the urine.

Half-Life: 7 days.

Time/Action Profile ⬆ ⬇

(tumor response)

ROUTEONSETPEAKDURATION
PO4–10 wkseveral moseveral wk



Contraind./Precautions ⬆ ⬇

Contraindicated in:

Use Cautiously in:

Adv. Reactions/Side Effects ⬆ ⬇

CV: DVT, edema

Derm: hot flashes

EENT: blurred vision

F and E: hypercalcemia

GI: nausea, vomiting

GU: UTERINE MALIGNANCIES, vaginal bleeding

Hemat: leukopenia, thrombocytopenia

MS: bone pain

Neuro: confusion, depression, headache, STROKE, weakness.

Resp: PE

Misc: tumor flare

Interactions ⬆ ⬇

Drug-drug:

Route/Dosage ⬆ ⬇

Metastatic Breast Cancer

Adjuvant Treatment of Breast Cancer

Prevention of Breast Cancer in High-Risk Women or Ductal Carcinoma in Situ

Availability ⬆ ⬇

(Generic available)

Assessment ⬆ ⬇

Lab Test Considerations:

Implementation ⬆ ⬇

Patient/Family Teaching ⬆ ⬇

Evaluation/Desired Outcomes ⬆ ⬇

US Brand Names ⬆ ⬇

Soltamox

Code ⬆

NDC Code