Generic drug: fulvestrant

Brand name: Faslodex

What is Faslodex (fulvestrant), and how does it work?

Faslodex (fulvestrant) is a prescription medicine used to treat advanced breast cancer or breast cancer that has spread to other parts of the body (metastatic).

Faslodex may be used alone, if you have gone through menopause, and your advanced breast cancer is:

  • hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative and has not been previously treated with endocrine therapy or
  • HR-positive and has progressed after endocrine therapy.

Faslodex may be used in combination with ribociclib, if you have gone through menopause, and your advanced or metastatic breast cancer is HR-positive and HER2-negative, and has not been previously treated with endocrine therapy or has progressed after endocrine therapy.

Faslodex may be used in combination with palbociclib or abemaciclib if your advanced or metastatic breast cancer is HR-positive and HER2-negative, and has progressed after endocrine therapy.

What are the side effects of Faslodex?

Faslodex may cause serious side effects, including:

  • Injection site related nerve damage. Call your healthcare provider if you develop any of the following symptoms in your legs following a Faslodex injection:

The most common side effects of Faslodex include:

Faslodex may cause fertility problems in males and females. Talk to your healthcare provider if you plan to become pregnant.

Tell your healthcare provider if you have any side effect that bothers you or that does not go away.

These are not all of the possible side effects with Faslodex. For more information, ask your healthcare provider or pharmacist.

Call your healthcare provider for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

SLIDESHOW

Breast Cancer Awareness: Symptoms, Diagnosis, and Treatment See Slideshow

What is the dosage for Faslodex?

Recommended Dose

Monotherapy
  • The recommended dose of Faslodex is 500 mg to be administered intramuscularly into the buttocks (gluteal area)slowly (1 -2 minutes per injection) as two 5 mL injections, one in each buttock,on Days 1, 15, 29, and once monthly thereafter.
Combination Therapy
  • When Faslodex is used in combination with palbociclib, abemaciclib, or ribociclib, the recommended doseof Faslodex is 500 mg to be administered intramuscularly into the buttocks (gluteal area) slowly (1 -2 minutes per injection) as two 5 mL injections, onein each buttock,on Days1, 15, 29,and once monthly thereafter.
  • When Faslodex is used in combination with palbociclib, the recommended dose of palbociclib is a 125 mg capsule taken orally once daily for 21 consecutive days followed by 7 days off treatment to comprise a complete cycle of 28 days. Palbociclib should be taken with food. Refer to the Full Prescribing Information for palbociclib.
  • When Faslodex is used in combination with abemaciclib, the recommended dose of abemaciclib is 150 mg orally, twice daily. Abemaciclib may betaken with or without food.Refer to the Full Prescribing Information for abemaciclib.
  • When Faslodex is used in combination with ribociclib, the recommended dose of ribociclib is 600 mg taken orally, once daily for 21 consecutive days followed by 7 days off treatment resulting in a complete cycle of 28 days. Ribociclib can be taken with or without food. Refer to the Full Prescribing Information for ribociclib.
  • Pre/perimenopausal women treated with the combination ofFaslodex pluspalbociclib, abemaciclib, or ribociclib, should be treated with luteinizing hormone-releasing hormone (LHRH) agonists according to current clinical practice standards.

Dose Modification

Monotherapy

Hepatic Impairment

  • A dose of 250 mg is recommended for patients with moderate hepatic impairment (Child-Pugh class B) to be administered intramuscularly into the buttock (gluteal area) slowly (1 -2 minutes) as one 5 mL injection on Days 1, 15, 29, and once monthly thereafter.
  • Faslodex has not been evaluated in patients with severe hepatic impairment (Child-Pugh class C).
Combination Therapy
  • When Faslodex is used in combination with palbociclib, abemaciclib, or ribociclib, refer to monotherapy dose modification instructions for Faslodex.
  • Refer to the Full Prescribing Information of co-administered palbociclib, abemaciclib, or ribociclib for dose modification guidelines in the eventof toxicities, for use with concomitant medications, and other relevant safety information.

What drugs interact with Faslodex?

  • There are no known drug-drug interactions. Although, fulvestrant is metabolized by CYP 3A4 in vitro, drug interactions studies with ketoconazole or rifampin did not alter fulvestrant pharmacokinetics.
  • Dose adjustment is not needed in patients co-prescribed CYP 3A4 inhibitors or inducers.

Is Faslodex safe to use while pregnant or breastfeeding?

  • Based on findings from animal studies and its mechanism of action, Faslodex can cause fetal harm when administered to a pregnant woman.
  • There are no available data in pregnant women to inform the drug-associated risk.
  • There is no information regarding the presence of fulvestrant in human milk, nor of its effects on milk production or breastfed infant.
  • Fulvestrant can be detected in rat milk.
  • Because of the potential for serious adverse reactions in breastfed infants from Faslodex, advise a lactating woman not to breastfeed during treatment with Faslodex and for one year after the final dose.

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Medically Reviewed on 4/29/2021
References
All sections courtesy of the U.S. Food and Drug Administration