polyestradiol phosphate

L02AA02

Forms & Strengths

Adult Dosing

Palliative treatment of advanced prostatic carcinoma: 80 mg to 160 mg (2 to 4 mL) intramuscularly every 2 to 4 weeks
Maintenance dose: adjusted based on clinical response and serum acid phosphatase levels, typically 40 mg to 80 mg every 2 to 4 weeks

Pediatric Dosing

Indications

Mechanism of Action

Polymerized ester of estradiol that acts as a slow-release estrogen depot
Suppresses luteinizing hormone (LH) release via negative feedback on the hypothalamus-pituitary axis
Reduces serum testosterone concentrations to castrate levels, inhibiting growth of androgen-dependent prostate cancer tissue

Contraindications

Known or suspected carcinoma of the breast (except in appropriately selected patients being treated for metastatic disease)
Active deep vein thrombosis, pulmonary embolism, or a history of these conditions
Active or recent arterial thromboembolic disease (e.g., stroke, myocardial infarction)
Undiagnosed abnormal genital bleeding
Severe hepatic impairment or active liver disease
Known hypersensitivity to estradiol or any component of the formulation

Adverse Reactions

Thromboembolic events (deep vein thrombosis, pulmonary embolism, myocardial infarction, stroke)
Cardiovascular events (fluid retention, hypertension, congestive heart failure)
Endocrine/Metabolic effects (gynecomastia, impotence, decreased libido, weight gain)
Hepatic effects (elevated liver transaminases, jaundice)
Other effects (nausea, vomiting, headache, dizziness, injection site reactions)

Drug Interactions

Coadministration with CYP3A4 inducers (e.g., rifampin, carbamazepine, phenytoin) may decrease estrogen efficacy
Coadministration with CYP3A4 inhibitors (e.g., ketoconazole, erythromycin) may increase estrogen exposure
Estrogens may reduce the efficacy of anticoagulants (e.g., warfarin), though increased thrombosis risk warrants extreme caution with combination
May decrease the therapeutic efficacy of antihypertensive agents due to fluid retention and sodium-retaining properties

Curated Content: Needs Vetting Before Put to Clinical Use