Fulvestrant (fulvestrant)
Last reviewed · Source: First Databank (FDB) drug data
Overview
Fulvestrant, an estrogen antagonist, is an antineoplastic agent.
Fulvestrant, a 7alpha-alkylsulfinyl analog of estradiol, is an estrogen antagonist. Data from animal studies indicate that fulvestrant does not possess estrogen-agonist activity. The drug competitively binds to and downregulates estrogen receptors in human breast cancer cells.
Fulvestrant has been shown to inhibit the growth of tamoxifen-resistant as well as estrogen-sensitive human breast cancer (MCF-7) cell lines in vitro and in vivo. Data from studies in animals indicate that the drug also may block the uterotropic action of estradiol. Fulvestrant does not appear to exhibit peripheral steroidal effects in postmenopausal women, as evidenced by an absence of appreciable changes in plasma concentrations of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) after receiving 250 mg of fulvestrant IM monthly.
Peak plasma concentrations of fulvestrant are attained approximately 7 days after IM administration and persist for at least 1 month. Steady-state plasma fulvestrant concentrations usually are achieved within 3-6 months when the drug is administered once-monthly by IM injection. Fulvestrant appears to be rapidly and extensively distributed, principally into the extravascular space.
The drug is approximately 99% bound to plasma proteins, with very low-density lipoprotein (VLDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, and high-density lipoprotein (HDL)-cholesterol being the major binding components.
Fulvestrant is extensively metabolized, principally in the liver. Metabolism of fulvestrant appears to involve a combination of various biotransformation pathways (e.g., oxidation, aromatic hydroxylation, conjugation) that are similar to those responsible for the elimination of endogenous steroids. Results from in vitro studies indicate that the cytochrome P-450 (CYP) 3A4 isoenzyme (CYP3A4) may be the only CYP microsomal enzyme involved in the oxidation of fulvestrant; however, the relative contribution of CYP and non-CYP routes in vivo currently is not known.
Metabolites of fulvestrant exhibit pharmacologic activity that is similar to or less than that of the parent compound. The elimination half-life of fulvestrant is about 40 days. Approximately 90 and less than 1% of fulvestrant is excreted in feces and urine, respectively, as metabolites.
USES: Fulvestrant is used to treat certain types of breast cancer. Breast cancer cells need the hormone estrogen in order to grow. Fulvestrant works by blocking the effect of estrogen, slowing tumor cell growth.
Generic name: fulvestrant
Pronunciation: (ful-VES-trant)
Reference product & biosimilars
No reference, biosimilar or interchangeable associated with this drug.
Today’s intelligence on Fulvestrant
Indications
The following indications are listed for Fulvestrant:
- Hormone Receptor (Hr)-Positive, Her2-Negative Advanced Female Breast Cancer
- Hormone Receptor Positive Postmenopausal Advanced Breast Cancer
Also known as: Hormone Receptor (Hr)-Positive, Her2-Negative Metastatic Female Breast Cancer, Hr+, Human Epidermal Growth Factor Receptor 2 (Her2)- Advanced Breast Cancer In Woman, Hr+, Human Epidermal Growth Factor Receptor 2 (Her2)- Metastatic Female Breast.
Dosing
No dosing information is available for this tab.
No dosing information is available for this tab.
No dosing information is available for this tab.
No dosing information is available for this tab.
Drug interactions
There is no enhanced messaging for this drug.
There are no contraindication interactions for this drug.
There are no severe interactions for this drug.
There are no moderate interactions for this drug.
Contraindications
Known hypersensitivity to fulvestrant, benzyl alcohol, or any ingredient in the formulation.
There are no contraindication contraindications for this drug.
There are no severe contraindications for this drug.
There are no moderate contraindications for this drug.
Adverse reactions
The most common adverse effects of fulvestrant are adverse GI effects (e.g., nausea, vomiting, constipation, diarrhea, abdominal pain ), headache, back pain, vasodilation (hot flushes), and pharyngitis, which occurred in approximately 52, 15, 14, 18, and 16% of patients, respectively, who received the drug in clinical studies. Other adverse effects occurring in 5-23% of patients receiving fulvestrant (in order of descending frequency) include asthenia, pain, nutritional disorders, bone pain, dyspnea, injection site pain, increased cough, pelvic pain, anorexia, peripheral edema, rash, chest pain, flu syndrome, dizziness, insomnia, fever, paresthesia, urinary tract infection, depression, anxiety, and sweating. Injection site reactions with mild transient pain and inflammation were reported in 7% of patients receiving a single 5-mL injection of fulvestrant in one study and in 27% of those who received two 2.5-mL injections of the drug in another study.
Vaginal bleeding has been reported infrequently (less than 1%), usually during the first 6 weeks of changing from existing hormonal therapy to fulvestrant; however, if bleeding persists, the manufacturer states that further clinical evaluations may be necessary.
There are no severe adverse reactions for this drug.
There are no less severe adverse reactions for this drug.
Precautions
No enhanced messaging available.
Safety and efficacy of fulvestrant have not been established in pediatric patients.
Category D. (See Users Guide for a definition and see Warnings: Fetal/Neonatal Morbidity and Mortality, in Cautions for additional information.)
Fulvestrant is distributed into milk in rats; not known whether the drug is distributed into human milk. Discontinue nursing or the drug, taking into account the importance of the drug to the woman.
Objective response rates reported in patients 65 years of age and older (11-16%) appear to be slightly lower than those reported in younger adults (22-24%).
The pharmacokinetics of fulvestrant are not altered substantially by age; therefore, the manufacturer states that dosage adjustment is not necessary in geriatric patients.
ICD codes
No ICD codes are available for this drug.
Formulary status
Search health-plan coverage for this drug by ZIP code.
Choose the first character of a health plan name.
Last reviewed · Source: First Databank (FDB) drug data
On this page
Actions
Sign in to save favorites
Saving this drug requires a free Physicians Office Resource account.