anastrozole

High Alert

Adjuvant treatment of postmenopausal hormone receptor-positive early breast cancer.
Initial therapy in women with postmenopausal hormone receptor-positive or hormone receptor unknown, locally advanced, or metastatic breast cancer.
Advanced postmenopausal breast cancer in women with disease progression despite tamoxifen therapy.

Action ⬆ ⬇

Inhibits the enzyme aromatase, which is partially responsible for conversion of precursors to estrogen.

Therapeutic effects:

Lowers levels of circulating estrogen, which may halt progression of estrogen-sensitive breast cancer.

Pharmacokinetics ⬆ ⬇

Absorption: 83–85% absorbed following oral administration.

Distribution: Unknown.

Metabolism/Excretion: 85% metabolized by the liver; 11% excreted renally.

Half-Life: 50 hr.

Time/Action Profile ⬆ ⬇

(lowering of serum estradiol)

ROUTE	ONSET	PEAK	DURATION
PO	within 24 hr	14 days	6 days‡

‡Following cessation of therapy.

Contraind./Precautions ⬆ ⬇

Contraindicated in:

OB: Pregnancy;
Lactation: Lactation.

Use Cautiously in:

Ischemic heart disease;
Rep: Women of reproductive potential;
Pedi: Safety and effectiveness not established in children.

Adv. Reactions/Side Effects ⬆ ⬇

CV: angina, MI, peripheral edema

Derm: hot flashes, rash, sweating

EENT: pharyngitis

F and E: hypercalcemia

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

GU: ↓fertility (females), pelvic pain, vaginal bleeding, vaginal dryness

Metab: ↑weight, hypercholesterolemia

MS: back pain, arthritis, bone pain, carpal tunnel syndrome, fracture, myalgia

Neuro: headache, weakness, dizziness., paresthesia

Resp: cough, dyspnea

Misc: pain, HYPERSENSITIVITY REACTIONS (INCLUDING ANAPHYLAXIS AND ANGIOEDEMA)

Interactions ⬆ ⬇

Drug-drug:

None reported.

Route/Dosage ⬆ ⬇

PO (Adults ): 1 mg once daily.

Availability ⬆ ⬇

(Generic available)

Tablets: 1 mg

Assessment ⬆ ⬇

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

Lab Test Considerations:

Obtain a negative pregnancy test before starting therapy.May cause ↑ GGT, AST, ALT, alkaline phosphatase, total cholesterol, and LDL cholesterol levels.

Implementation ⬆ ⬇

PO: Take medication consistently with regard to food.

Patient/Family Teaching ⬆ ⬇

Instruct patient to take medication as directed. Take missed doses as soon as remembered unless it is almost time for next dose. Do not double doses. Advise patient to read the Patient Information leaflet before starting and with each Rx refill; changes may occur.
- Inform patient of potential for adverse reactions, and advise patient to notify health care professional immediately if allergic reactions (swelling of the face, lips, tongue, and/or throat, difficulty in swallowing and/or breathing), liver problems (general feeling of not being well, yellowing of skin or whites of eyes, pain on the right side of abdomen), skin reactions (lesions, ulcers, or blisters), or chest pain occurs.
- Advise patient that vaginal bleeding may occur during first few wk after changing over from other hormonal therapy. Continued bleeding should be evaluated.
- Teach patient to report increase in pain so treatment can be initiated.
- May cause fetal harm. Advise female patients of reproductive potential to use effective contraception during and for at least 3 wk after last dose of therapy, to avoid breastfeeding for at least 2 wk after last dose, and to notify health care professional immediately if pregnancy is planned or suspected. May impair female fertility.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇