Drug reference

tamoxifen citrate

Selective estrogen receptor modulator (SERM) · Antineoplastic, Infertility Agent

Selective estrogen receptor modulator (SERM)Antineoplastic, Infertility Agent

CDSCO approved

EXCRETION

—

not curated

INTERACTIONS

—

none in our sources

PREGNANCY

FDA category + note

Mechanism

It acts as potent estrogen antagonist in breast carcinoma cells, blood vessels and at some peripheral sites, but as partial agonist in uterus, bone, liver and pituitary.

Indications

Primary breast carcinoma in premenopausal women (ER-positive)Metastatic breast carcinoma in premenopausal women (ER-positive)Surgically treated cancer of male breastPrimary prophylaxis of breast cancer in high-risk womenAdjuvant therapy for breast carcinoma (postmastectomy)Male infertility

Dosing

Adult: 20 mg/day in 1 or 2 doses, max. 40 mg/day
Max dose: 40 mg/day

Pharmacokinetics

Duration

long duration of action

Half-life

biphasic plasma t½ (10 hours and 7 days)

Metabolism

metabolites are more potent antiestrogens

Excretion

primarily in bile

Contraindications

Increased risk of deep vein thrombosis
Existing endometrial hyperplasia or carcinoma

Side effects

Common

Hot flushesVomitingVaginal bleedingVaginal dischargeMenstrual irregularitiesDermatitis (infrequent)Anorexia (infrequent)Depression (infrequent)Mild leucopenia (infrequent)Ocular changes (infrequent)

Serious