Information about Fulvestrant
Liver safety of Fulvestrant
Fulvestrant therapy can be associated with serum enzyme elevations, but has yet to be linked to instances of clinically apparent acute liver injury in the published literature.
Mechanism of action of Fulvestrant
Fulvestrant (ful ves' trant) is a steroidal antiestrogen that is potent and direct antagonist or "down regulator" of the estrogen receptor. Fulvestrant is a synthetic derivative of estradiol and binds to the estrogen receptor with 100 times more potency than tamoxifen. It not only blocks the effects of estrogen, but also alters the structure of the estrogen receptor and further decreases the intracellular effects of estrogen. Unlike tamoxifen, fulvestrant is a pure antiestrogen and has no estrogen receptor agonist activity. Fulvestrant has been found to be as effective as tamoxifen as a first line agent to treat metastatic breast cancer, and is similar in efficacy to the aromatase inhibitors in women with progressive disease despite tamoxifen therapy.
FDA approval information for Fulvestrant
Fulvestrant was approved for use in the United States in 2002.
Clinical use of Fulvestrant
Dosage and administration for Fulvestrant
Fulvestrant is available as a liquid solution in 5 mL vials of 250 mg for intramuscular injection under the brand name Faslodex. The usual dose for treating breast cancer is 500 mg given in two intramuscular injections in the buttocks (slowly, over 1-2 minutes) on days 1, 15 and 29, and then monthly thereafter.
Side effects of Fulvestrant
Common side effects include injection site pain and reactions, nausea, anorexia, fatigue, headache, backache, muscle pains, host flashes, cough, dyspnea and constipation. Rare, but potentially severe side effects include hypersensitivity reactions.