diethylstilbestrol

G03CC05

Forms & Strengths

Oral tablets: 1 mg, 5 mg (historically available; largely withdrawn globally due to toxicity and teratogenicity)

Adult Dosing

Prostate carcinoma (historical): 1 mg to 3 mg orally once daily
Menopausal symptoms (historical): 0.1 mg to 0.5 mg orally daily
Postcoital contraception (historical 'morning-after pill'): 25 mg orally twice daily for 5 consecutive days starting within 72 hours of unprotected intercourse

Pediatric Dosing

Indications

Palliative treatment of advanced androgen-dependent prostate cancer (historical)
Postcoital emergency contraception (historical)
Severe vasomotor symptoms of menopause (historical)

Mechanism of Action

Non-steroidal synthetic estrogen that binds to estrogen receptors in target tissues
Suppresses luteinizing hormone (LH) and follicle-stimulating hormone (FSH) release via negative feedback
Reduces serum testosterone concentrations to castrate levels in males

Contraindications

Known or suspected pregnancy (severe teratogenicity and risk of clear-cell adenocarcinoma in female offspring)
Active thrombophlebitis or thromboembolic disorders
History of estrogen-dependent neoplasia (e.g., breast cancer)
Undiagnosed abnormal genital bleeding
Active liver disease or hepatic dysfunction

Adverse Reactions

Venous thromboembolism (deep vein thrombosis, pulmonary embolism)
Myocardial infarction and cerebrovascular accident
Gynecomastia, breast tenderness, and impotence in males
Nausea, vomiting, and anorexia
Fluid retention, edema, and hypertension
Transgenerational effects: vaginal clear-cell adenocarcinoma in female offspring exposed in utero

Drug Interactions

Anticoagulants (coumarin derivatives): estrogen may decrease efficacy, altering anticoagulant requirements
Hepatic enzyme inducers (e.g., rifampin, barbiturates, carbamazepine): may increase metabolism and decrease efficacy of estrogens
Corticosteroids: potential for enhanced pharmacologic effects and toxicity of corticosteroids
Antidiabetic agents: estrogens may impair glucose tolerance, necessitating dosage adjustment of insulin or oral hypoglycemics

Curated Content: Needs Vetting Before Put to Clinical Use