fulvestrant

High Alert

Hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer in postmenopausal women not previously treated with endocrine therapy (as monotherapy).
HR-positive advanced breast cancer in postmenopausal women with progressive disease that has not responded to endocrine therapy (as monotherapy).
HR-positive, HER2-negative advanced or metastatic breast cancer in women with disease progression after endocrine therapy (in combination with palbociclib or abemaciclib).
HR-positive, HER2-negative advanced or metastatic breast cancer in women as initial endocrine-based therapy or following disease progression on endocrine therapy (in combination with ribociclib).

Action ⬆ ⬇

Competitively binds to estrogen receptors. Binding results in downregulation of estrogen receptor protein in cancerous breast tissue.

Therapeutic effects:

Decreased progression of HR-positive breast cancer.

Pharmacokinetics ⬆ ⬇

Absorption: Well absorbed following IM administration.

Distribution: Rapidly and extensively distributed.

Protein Binding: 99%.

Metabolism/Excretion: Mostly metabolized by the liver; negligible renal elimination.

Half-Life: 40 days.

Time/Action Profile ⬆ ⬇

(effect on estrogen receptors)

ROUTE	ONSET	PEAK	DURATION
IM	rapid	7 days	30 days

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Bleeding disorders, thrombocytopenia, concurrent anticoagulant therapy;
Severe hepatic impairment;
OB: Pregnancy;
Lactation: Lactation.

Use Cautiously in:

Moderate hepatic impairment;
Rep: Women of reproductive potential;
Pedi: Safety and effectiveness not established in children.

Adv. Reactions/Side Effects ⬆ ⬇

CV: chest pain, edema

Derm: hot flushing, rash, sweating

EENT: pharyngitis

GI: abdominal pain, constipation, diarrhea, nausea, vomiting, anorexia

GU: ↓fertility, pelvic pain, urinary tract infection

Hemat: anemia

Local: pain/inflammation at injection site

MS: back pain, bone pain, arthritis

Neuro: headache, weakness, anxiety, depression, dizziness, injection site-related neurological events (including sciatica and neuropathy), insomnia, paresthesia

Resp: cough, dyspnea

Misc: fever, flu syndrome

Interactions ⬆ ⬇

Drug-drug:

None reported.

Route/Dosage ⬆ ⬇

Monotherapy

IM (Adults ): 500 mg on Days 1, 15, and 29, and then once monthly.

Hepatic Impairment

IM (Adults ): Moderate hepatic impairment: 250 mg on Days 1, 15, and 29, and then once monthly.

In Combination with Palbociclib, Abemaciclib, or Ribociclib

IM (Adults ): 500 mg on Days 1, 15, and 29, and then once monthly. Pre-/perimenopausal women should also be treated with luteinizing hormone-releasing hormone (LHRH) agonist therapy.

Hepatic Impairment

IM (Adults ): Moderate hepatic impairment: 250 mg on Days 1, 15, and 29, and then once monthly (given as a single injection).

Availability ⬆ ⬇

(Generic available)

Solution for injection (prefilled syringes): 50 mg/mL

Assessment ⬆ ⬇

Assess patient for pain and other side effects periodically during therapy.

Lab Test Considerations:

A negative pregnancy test should be determined within 7 days of starting therapy.
- May interfere with estradiol measurement resulting in falsely ↑ estradiol levels.

Implementation ⬆ ⬇

IM: Follow proper technique for injection using the manufacturer's instructions for the use of the SafetyGlide syringe and needle. Inject slowly over 1–2 min into the gluteus muscle. A 500-mg dose should be injected as two 5-mL injections, one in each buttock. Ventrogluteal is the preferred site. If dorsogluteal site is used, use caution; proximity of sciatic nerve increases risk of sciatica, neuralgia, neuropathic pain, and peripheral neuropathy.

Patient/Family Teaching ⬆ ⬇

Inform patient that fulvestrant may cause mild pain and inflammation at injection site.
Inform patient of potential for adverse reactions and advise them to notify health care professional.
Advise patient to report an ↑ in pain so treatment with analgesics can be initiated.
Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications.
Rep: May cause fetal harm. Advise females of reproductive potential to use effective contraception during and for at least 1 yr after last dose and to avoid breastfeeding during and for 1 yr after last dose. May impair fertility in female and male patients of reproductive potential.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇