Fulvestrant

Generic name: fulvestrant
Brand name: Fasoldex

Drug Class: Estrogen Receptor Antagonist

Dosage Form: Injection

Route of Administration: Intramuscular

Dose:

• Typically administered as 500 mg once a month

Mechanism of Action: Fulvestrant competitively binds to estrogen receptors on various target tissues, including breast cancer cells, without any estrogen agonist effects. This binding leads to degradation of the estrogen receptors, inhibiting the cellular effects of estrogens and leading to tumor regression.

Drug Usage Cases: Fulvestrant is used in the treatment of hormone receptor-positive metastatic breast cancer in postmenopausal women with disease progression following anti-estrogen therapy.

Drug Contraindications: Contraindicated in patients with known hypersensitivity to the drug or any of its components and in pregnant women due to its potential for harming the fetus.

Side Effects: Common side effects include injection site pain, nausea, and fatigue. Serious side effects can include liver enzyme elevations, thromboembolism, and bone marrow depression.

Warnings: Fulvestrant should be used with caution in patients with bleeding diatheses, thrombocytopenia, or anticoagulant use. Liver function should be monitored due to potential hepatotoxicity.

Use During Pregnancy or Breastfeeding: Classified under FDA Pregnancy Category D. It is known to cause harm when administered to a pregnant woman and is contraindicated in pregnant women. There is insufficient information on the excretion of fulvestrant in human milk.