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Indications

REMS

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:

Availability

(Generic available)

Route/Dosage

Metastatic Breast Cancer

Adjuvant Treatment of Breast Cancer

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

US Brand Names

Soltamox

Action

Therapeutic Effects:

Classifications

Therapeutic Classification: antineoplastics

Pharmacologic Classification: antiestrogens

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

Patient/Family Teaching

Pronunciation

ta-MOX-i-fen audio

Code

NDC Code*