Class: Aromatase inhibitor
- Tablets 1 mg
A selective nonsteroidal aromatase inhibitor. It lowers serum estradiol concentrations.
Absorption is rapid, with T max at about 2 h. Food decreases C max by 16% and delays T max to 5 h.
40% protein bound.
Metabolized in the liver (N-dealkylation, hydroxylation, and glucuronidation) via CYP1A2, CYP2C8/2C9, and CYP3A4.
Half-life is approximately 50 h; approximately 10% is excreted in the urine. Approximately 85% undergoes hepatic metabolism.
Special PopulationsRenal Function Impairment
Renal Cl decreased proportionally with CrCl and was approximately 50% lower in those with severe renal function impairment (CrCl less than 30 mL/min per 1.73 m 2 ); this reduced total body Cl by 10%. No dosage adjustment is needed for renal impairment.Hepatic Function Impairment
Oral Cl was approximately 30% lower in those with stable hepatic cirrhosis, but plasma concentrations were within normal range. Dosage adjustment is not necessary. Has not been studied in patients with severe hepatic impairment.Elderly
The pharmacokinetics of anastrozole are not affected by age.Children
Safety and efficacy not established.
Indications and Usage
Advanced breast cancer in postmenopausal women with progression following tamoxifen therapy; first-line treatment of postmenopausal women with hormone receptor–positive or hormone receptor unknown locally advanced or metastatic breast cancer; for adjuvant treatment of postmenopausal women with hormone receptor–positive early breast cancer.
Women who are or plan to become pregnant; premenopausal women; patients who have shown hypersensitivity reaction to the drug or any of the excipients.
Dosage and AdministrationBreast Cancer
PO 1 mg every day with or without food.Unlabeled Uses
PO 1 mg once daily for a mean duration of 4.7 mo (range, 1 to 24 mo).
Store tablets at controlled room temperature (68° to 77°F).
Estrogens may diminish the actions of anastrozole. Coadministration is not recommended.
May reduce blood estradiol levels. This may affect the efficacy of oral contraceptives.Tamoxifen
Coadministration is not recommended.
Laboratory Test Interactions
Elevations of gamma glutamyltransferase (GGT) levels have been observed among patients with liver metastases.
Vasodilation (36%); hypertension (13%); ischemic CV disease, thromboembolic disease (4%); venous thromboembolic events (3%); deep venous thromboembolic events, ischemic cerebrovascular event (2%).
Asthenia, mood disturbances (19%); headache (18%); depression (13%); insomnia (10%); dizziness (8%); paraesthesia (7%); anxiety (6%); hypertonia (3%); lethargy (1%).
Rash (11%); sweating (5%); erythema multiforme, mucocutaneous disorder, Stevens-Johnson (postmarketing).
Pharyngitis (14%); cataract specified (6%).
GI disturbance (34%); nausea (20%); vomiting (11%); abdominal pain, constipation, diarrhea (9%); anorexia (8%); dyspepsia, GI disorder (7%); dry mouth (6%).
Breast pain, UTI (8%); vulvovaginitis (6%); breast neoplasm, vaginal hemorrhage (5%); vaginal discharge, vaginitis (4%); leucorrhea (3%); vaginal dryness (2%).
Lymphedema (10%); anemia (4%); leukopenia (postmarketing).
Increased alkaline phosphatase, ALT, AST, bilirubin, GGT; hepatitis (postmarketing).
Allergic reactions including anaphylaxis, angioedema, and urticaria (postmarketing).
Edema (11%); peripheral edema (10%); hypercholesterolemia, weight gain (9%).
Musculoskeletal events (36%); arthritis (17%); arthralgia (15%); back pain, bone pain (12%); osteoporosis (11%); fracture (10%); arthrosis, pelvic pain (7%); joint disorder, myalgia (6%).
Dyspnea, increased cough (11%); sinusitis (6%); bronchitis (5%).
Hot flashes (36%); pain (17%); accidental injury (10%); infection (9%); chest pain, flu syndrome (7%); cyst, neoplasm (5%); tumor flare (3%).
Monitor cholesterol levels and BMD periodically.
Category X .
Safety and efficacy not established.
May decrease BMD.
Consider the risks and benefits in patients with preexisting ischemic heart disease.
May increase serum cholesterol levels.
Patients who did not respond to tamoxifen rarely respond to anastrozole.
- Advise patient that medication can be taken without regard to meals, but to take with food if GI upset occurs.
- Advise women that anastrazole may cause fetal harm. Advise patients to avoid becoming pregnant.
- Instruct patient to immediately report any of the following to the health care provider: dizziness or fainting, pain in groin or calves, sharp chest pain or sudden shortness of breath, sudden severe headache, vision or speech problems, weakness or numbness of arms or legs.
- Advise patient that drug may cause dizziness and to use caution while driving or performing other tasks requiring mental alertness.
- Advise patient that this medicine may decrease bone strength, which may increase the risk of fractures.
- Advise patient with preexisting ischemic heart disease of the increased risk of CV events.
- Advise patients that this medication may increase cholesterol.
Copyright © 2009 Wolters Kluwer Health.