anastrozole (Rx)

Brand and Other Names:Arimidex
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Dosing & Uses

AdultPediatric

Dosage Forms & Strengths

tablet

  • 1mg

Breast Cancer

Postmenopausal women

Advanced

  • 1 mg PO once daily; continue until tumor progression

Early

  • Adjuvant treatment: 1 mg PO qDay; optimal duration unknown; 5 years in clinical trials

Administration

May be taken with or without food

Hepatic Impairment

Mild-to-moderate impairment or stable hepatic cirrhosis: Dose adjustment not necessary

Severe hepatic impairment: Not studied

Use not recommended

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Interactions

Interaction Checker

and anastrozole

No Results

     activity indicator 
    No Interactions Found
    Interactions Found

    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

          Minor

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            Adverse Effects

            >10%

            Hot flashes (12-36%)

            Vasodilation (25-36%)

            Fatigue (19%)

            Mood disturbances (19%)

            Nausea and vomiting (19%)

            Weakness (16-19%)

            Arthritis (17%)

            Pain (17%)

            Arthralgia (2-15%)

            Pharyngitis (14%)

            Depression (13%)

            Hypertension (2-13%)

            Bone pain (11%)

            Increased cough (11%)

            Osteoporosis (11%)

            Rash (8-11%)

            1-10%

            Accidental injury (10%)

            Back pain (10%)

            Fracture (10%)

            Headache (10%)

            Insomnia (10%)

            Peripheral edema (10%)

            Dyspnea (8-10%)

            Abdominal pain (9%)

            Infection (9%)

            Lymphedema (9%)

            Diarrhea (8-9%)

            Constipation (7-9%)

            Breast pain (8%)

            Dizziness (8%)

            Urinary tract infection (8%)

            Chest pain (7%)

            Dyspepsia (7%)

            Paresthesia (5-7%)

            Anxiety (6%)

            Cataracts (6%)

            Flu syndrome (6%)

            Sinusitis (6%)

            Vulvovaginitis (6%)

            Xerostomia (6%)

            Breast neoplasm (5%)

            Bronchitis (5%)

            Cyst (5%)

            Diaphoresis (5%)

            Neoplasm (5%)

            Vaginal bleeding (5%)

            Fractures of spine, hip, or wrist (4%)

            Ischemic cardiovascular disease (4%)

            Vaginal hemorrhage (4%)

            Vaginitis (4%)

            Leukorrhea (3-4%)

            Deep vein thrombosis (2%)

            Endometrial cancer (intact uterus at baseline) (2%)

            Ischemic cerebrovascular event (2%)

            Weight gain (2%)

            Lethargy (1%)

            Postmarketing Reports

            Hepatitis; increased alkaline phosphatase, aminotransferases, gamma-glutamyl transferase, and bilirubin

            Allergic reactions, including angioedema, urticaria, and anaphylaxis

            Rash, including mucocutaneous disorders (eg, erythema multiforme, Stevens-Johnson syndrome)

            Myalgia, trigger finger, and hypercalcemia (with or without increase in parathyroid hormone)

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            Warnings

            Contraindications

            Hypersensitivity

            May cause fetal harm or loss; use is contraindicated in women who are or may become pregnant

            Cautions

            Increased incidence of ischemic cardiovascular events in women with preexisting ischemic heart disease; use only if benefits greatly outweigh risks

            Decreases lumbar spine and total hip bone mineral density; increased risk of fractures and osteoporosis; concurrent use with bisphosphonates may be useful in patients at risk for fractures; follow available guidelines for bone mineral density management in postmenopausal women; patients with preexisting osteopenia are at higher risk for developing osteoporosis

            Elevated serum cholesterol reported; monitor closely; use with caution in patients with hyperlipidemias; monitor and manage cholesterol levels with current guidelines for patients with LDL elevations

            Affords no clinical benefit to premenopausal women with breast cancer

            Increased risk of ischemic cardiovascular events in patients with pre-existing ischemic cardiac disease

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            Pregnancy & Lactation

            Pregnancy

            Based on findings from animal studies and mechanism of action, therapy may cause fetal harm when administered to pregnant woman; there are no studies on use in pregnant women

            Advise pregnant women and females of reproductive potential of potential risk to a fetus

            Verify pregnancy status of females of reproductive potential prior to initiation of therapy

            Based on animal studies, therapy can cause fetal harm when administered to a pregnant woman

            Advise females of reproductive potential to use effective contraception during treatment and for at least 3 weeks after last dose

            Based on studies in female animals, treatment may impair fertility in females of reproductive potential

            Animal data

            • Anastrozole caused embryo-fetal toxicities in rats at maternal exposure that were 9 times the human clinical exposure, based on area under the curve (AUC); in rabbits, anastrozole caused pregnancy failure at doses equal to or greater than 16 times the recommended human dose on a mg/m2 basis

            Lactation

            There are no data on presence of drug or metabolites in human milk, or effects on breast-fed child or on milk production; because many drugs are excreted in human milk and because of tumorigenicity shown for anastrozole in animal studies, or potential for serious adverse reactions in breast-fed child from treatment, advise lactating women not to breastfeed during treatment and for 2 weeks after last dose

            Pregnancy Categories

            A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

            B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

            C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

            D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

            X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

            NA: Information not available.

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            Pharmacology

            Mechanism of Action

            Selective nonsteroidal aromatase inhibitor; prevents conversion of androstenedione to estrone and estradiol in peripheral tissues, thereby significantly lowering serum estradiol concentrations; has no effect on adrenal corticosteroids or aldosterone

            Absorption

            Peak plasma concentration: 2 hr without food; 5 hr with food

            Onset: 24 hr (70% reduction); 2 weeks (80% reduction)

            Time to steady-state levels: 7 days

            Distribution

            Protein bound: 40%

            Metabolism

            Metabolized in liver via N-dealkylation, hydroxylation, and glucuronidation (85%)

            Metabolite: Triazole (inactive)

            Enzymes inhibited: CYP1A2, CYP2C9, CYP3A4 (at high concentrations; inhibition not significant at usual dose)

            Elimination

            Half-life: 50 hr

            Dialyzable: Yes

            Excretion: Urine (10%)

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            Images

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            Formulary

            FormularyPatient Discounts

            Adding plans allows you to compare formulary status to other drugs in the same class.

            To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.

            Adding plans allows you to:

            • View the formulary and any restrictions for each plan.
            • Manage and view all your plans together – even plans in different states.
            • Compare formulary status to other drugs in the same class.
            • Access your plan list on any device – mobile or desktop.

            The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
            4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
            QL Quantity Limits
            Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
            ST Step Therapy
            Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
            OR Other Restrictions
            Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
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            Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.