Arimidex
Anastrozole · Tablet · Oral
Uses
1 INDICATIONS AND USAGE ARIMIDEX is an aromatase inhibitor indicated for:
• Adjuvant treatment of postmenopausal women with hormone receptor-positive early breast cancer ( 1.1 )
• First-line treatment of postmenopausal women with hormone receptor-positive or hormone receptor-unknown locally advanced or metastatic breast cancer ( 1.2 )
• Treatment of advanced breast cancer in postmenopausal women with disease progression following tamoxifen therapy. Patients with ER-negative disease and patients who did not respond to previous tamoxifen therapy rarely responded to ARIMIDEX ( 1.3 ) 1.1 Adjuvant Treatment ARIMIDEX is indicated for adjuvant treatment of postmenopausal women with hormone receptor-positive early breast cancer. 1.2 First-Line Treatment ARIMIDEX is indicated for the first-line treatment of postmenopausal women with hormone receptor-positive or hormone receptor-unknown locally advanced or metastatic breast cancer. 1.3 Second-Line Treatment ARIMIDEX is indicated for the treatment of advanced breast cancer in postmenopausal women with disease progression following tamoxifen therapy. Patients with ER-negative disease and patients who did not respond to previous tamoxifen therapy rarely responded to ARIMIDEX.
Dosage and administration
One 1 mg tablet taken once daily ( 2.1 ) 2.1 Recommended Dose The dose of ARIMIDEX is one 1 mg tablet taken once a day. For patients with advanced breast cancer, ARIMIDEX should be continued until tumor progression. ARIMIDEX can be taken with or without food. For adjuvant treatment of early breast cancer in postmenopausal women, the optimal duration of therapy is unknown. In the ATAC trial, ARIMIDEX was administered for five years [see Clinical Studies ( 14.1 )] . No dosage adjustment is necessary for patients with renal impairment or for elderly patients [see Use in Specific Populations ( 8.6 )] . 2.2 Patients with Hepatic Impairment No changes in dose are recommended for patients with mild-to-moderate hepatic impairment. ARIMIDEX has not been studied in patients with severe hepatic impairment [see Use in Specific Populations ( 8.7 )] .
Dosage forms and strengths
The tablets are white, biconvex, film-coated containing 1 mg of anastrozole. The tablets are impressed on one side with a logo consisting of a letter “A” (upper case) with an arrowhead attached to the foot of the extended right leg of the “A” and on the reverse with the tablet strength marking “Adx 1”. 1 mg tablets ( 3 )
Contraindications
Hypersensitivity ARIMIDEX is contraindicated in any patient who has shown a hypersensitivity reaction to the drug or to any of the excipients. Observed reactions include anaphylaxis, angioedema, and urticaria [see Adverse Reactions ( 6.2 )] . Patients with demonstrated hypersensitivity to ARIMIDEX or any excipient ( 4 )
Warnings and precautions
• In women with pre-existing ischemic heart disease, an increased incidence of ischemic cardiovascular events occurred with ARIMIDEX use compared to tamoxifen use. Consider risks and benefits. ( 5.1 , 6.1 )
• Decreases in bone mineral density may occur. Consider bone mineral density monitoring. ( 5.2 , 6.1 )
• Increases in total cholesterol may occur. Consider cholesterol monitoring. ( 5.3 , 6.1 )
• Embryo-Fetal Toxicity: ARIMIDEX may cause fetal harm. Advise patients of the potential risk to a fetus and to use effective contraception. ( 5.4 , 8.1 ) 5.1 Ischemic Cardiovascular Events In women with pre-existing ischemic heart disease, an increased incidence of ischemic cardiovascular events was observed with ARIMIDEX in the ATAC trial (17% of patients on ARIMIDEX and 10% of patients on tamoxifen). Consider risk and benefits of ARIMIDEX therapy in patients with pre-existing ischemic heart disease [see Adverse Reactions ( 6.1 )] . 5.2 Bone Effects Results from the ATAC trial bone substudy at 12 and 24 months demonstrated that patients receiving ARIMIDEX had a mean decrease in both lumbar spine and total hip bone mineral density (BMD) compared to baseline. Patients receiving tamoxifen had a mean increase in both lumbar spine and total hip BMD compared to baseline. Consider bone mineral density monitoring in patients treated with ARIMIDEX [see Adverse Reactions ( 6.1 )] . 5.3 Cholesterol During the ATAC trial, more patients receiving ARIMIDEX were reported to have elevated serum cholesterol compared to patients receiving tamoxifen (9% versus 3.5%, respectively) [see Adverse Reactions ( 6.1 )] . 5.4 Embryo-Fetal Toxicity Based on findings from animal studies and its mechanism of action, ARIMIDEX can cause fetal harm when administered to a pregnant woman. 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/m 2 basis. Advise pregnant women and females of reproductive potential of the potential risk to a fetus. Advise females of reproductive potential to use effective contraception during therapy with ARIMIDEX and for at least 3 weeks after the last dose [see Use in Specific Populations ( 8.1 , 8.3 ) and Clinical Pharmacology ( 12.1 )] .
Side effects
Serious adverse reactions with ARIMIDEX occurring in less than 1 in 10,000 patients, are: 1) skin reactions such as lesions, ulcers, or blisters; 2) allergic reactions with swelling of the face, lips, tongue, and/or throat. This may cause difficulty in swallowing and/or breathing; and 3) changes in blood tests of the liver function, including inflammation of the liver with symptoms that may include a general feeling of not being well, with or without jaundice, liver pain or liver swelling [see Adverse Reactions ( 6.2 )] . Common adverse reactions (occurring with an incidence of ≥10%) in women taking ARIMIDEX included: hot flashes, asthenia, arthritis, pain, arthralgia, hypertension, depression, nausea and vomiting, rash, osteoporosis, fractures, back pain, insomnia, headache, bone pain, peripheral edema, increased cough, dyspnea, pharyngitis and lymphedema. In the ATAC trial, the most common reported adverse reaction (>0.1%) leading to discontinuation of therapy for both treatment groups was hot flashes, although there were fewer patients who discontinued therapy as a result of hot flashes in the ARIMIDEX group. Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. In the early breast cancer (ATAC) study, the most common (occurring with an incidence of ≥10%) side effects occurring in women taking ARIMIDEX included: hot flashes, asthenia, arthritis, pain, arthralgia, pharyngitis, hypertension, depression, nausea and vomiting, rash, osteoporosis, fractures, back pain, insomnia, headache, peripheral edema and lymphedema, regardless of causality. ( 6.1 ) In the advanced breast cancer studies, the most common (occurring with an incidence of >10%) side effects occurring in women taking ARIMIDEX included: hot flashes, nausea, asthenia, pain, headache, back pain, bone pain, increased cough, dyspnea, pharyngitis and peripheral edema. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact ANI Pharmaceuticals, Inc. at 1-855-204-1431 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 6.1 Clinical Trials Experience Adjuvant Therapy Adverse reaction data for adjuvant therapy are based on the ATAC trial [see Clinical Studies ( 14.1 )] . The median duration of adjuvant treatment for safety evaluation was 59.8 months and 59.6 months for patients receiving ARIMIDEX 1 mg and tamoxifen 20 mg, respectively. Adverse reactions occurring with an incidence of at least 5% in either treatment group during treatment or within 14 days of the end of treatment are presented in Table 1. Table 1 - Adverse reactions occurring with an incidence of at least 5% in either treatment group during treatment, or within 14 days of the end of treatment in the ATAC trial The combination arm was discontinued due to lack of efficacy benefit at 33 months of follow-up. Body system and adverse reactions by COSTART preferred term COSTART Coding Symbols for Thesaurus of Adverse Reaction Terms. A patient may have had more than 1 adverse reaction, including more than 1 adverse reaction in the same body system. ARIMIDEX 1 mg (N N=Number of patients receiving the treatment. = 3092) Tamoxifen 20 mg (N = 3094) Body as a whole Asthenia 575 (19) 544 (18) Pain 533 (17) 485 (16) Back pain 321 (10) 309 (10) Headache 314 (10) 249 (8) Abdominal pain 271 (9) 276 (9) Infection 285 (9) 276 (9) Accidental injury 311 (10) 303 (10) Flu syndrome 175 (6) 195 (6) Chest pain 200 (7) 150 (5) Neoplasm 162 (5) 144 (5) Cyst 138 (5) 162 (5) Cardiovascular Vasodilatation 1104 (36) 1264 (41) Hypertension 402 (13) 349 (11) Digestive Nausea 343 (11) 335 (11) Constipation 249 (8) 252 (8) Diarrhea 265 (9) 216 (7) Dyspepsia 206 (7) 169 (6) Gastrointestinal disorder 210 (7) 158 (5) Hemic and lymphatic Lymphedema 304 (10) 341 (11) Anemia 113 (4) 159 (5) Metabolic and nutritional Peripheral edema 311 (10) 343 (11) Weight gain 285 (9) 274 (9) Hypercholesterolemia 278 (9) 108 (3.5) Musculoskeletal Arthritis 512 (17) 445 (14) Arthralgia 467 (15) 344 (11) Osteoporosis 325 (11) 226 (7) Fracture 315 (10) 209 (7) Bone pain 201 (7) 185 (6) Arthrosis 207 (7) 156 (5) Joint Disorder 184 (6) 160 (5) Myalgia 179 (6) 160 (5) Nervous system Depression 413 (13) 382 (12) Insomnia 309 (10) 281 (9) Dizziness 236 (8) 234 (8) Anxiety 195 (6) 180 (6) Paresthesia 215 (7) 145 (5) Respiratory Pharyngitis 443 (14) 422 (14) Cough increased 261 (8) 287 (9) Dyspnea 234 (8) 237 (8) Sinusitis 184 (6) 159 (5) Bronchitis 167 (5) 153 (5) Skin and appendages Rash 333 (11) 387 (13) Sweating 145 (5) 177 (6) Special Senses Cataract Specified 182 (6) 213 (7) Urogenital Leukorrhea 86 (3) 286 (9) Urinary tract infection 244 (8) 313 (10) Breast pain 251 (8) 169 (6) Breast Neoplasm 164 (5) 139 (5) Vulvovaginitis 194 (6) 150 (5) Vaginal Hemorrhage Vaginal Hemorrhage without further diagnosis. 122 (4) 180 (6) Vaginitis 125 (4) 158 (5) Certain adverse reactions and combinations of adverse reactions were prospectively specified for analysis, based on the known pharmacologic properties and side effect profiles of the two drugs (see Table 2). Table 2 - Number of Patients with Pre-specified Adverse Reactions in ATAC Trial Patients with multiple events in the same category are counted only once in that category. ARIMIDEX N=3092 (%) Tamoxifen N=3094 (%) Odds-ratio 95% CI Hot Flashes 1104 (36) 1264 (41) 0.80 0.73 − 0.89 Musculoskeletal Events Refers to joint symptoms, including joint disorder, arthritis, arthrosis and arthralgia.
Drug interactions
• Tamoxifen: Do not use in combination with ARIMIDEX. No additional benefit seen over tamoxifen monotherapy. ( 7.1 , 14.1 )
• Estrogen-containing products: Combination use may diminish activity of ARIMIDEX. ( 7.2 ) 7.1 Tamoxifen Co-administration of anastrozole and tamoxifen in breast cancer patients reduced anastrozole plasma concentration by 27%. However, the co-administration of anastrozole and tamoxifen did not affect the pharmacokinetics of tamoxifen or N-desmethyltamoxifen. At a median follow-up of 33 months, the combination of ARIMIDEX and tamoxifen did not demonstrate any efficacy benefit when compared with tamoxifen in all patients as well as in the hormone receptor-positive subpopulation. This treatment arm was discontinued from the trial [see Clinical Studies ( 14.1 )] . Based on clinical and pharmacokinetic results from the ATAC trial, tamoxifen should not be administered with anastrozole. 7.2 Estrogen Estrogen-containing therapies should not be used with ARIMIDEX as they may diminish its pharmacological action. 7.3 Warfarin In a study conducted in 16 male volunteers, anastrozole did not alter the exposure (as measured by C max and AUC) and anticoagulant activity (as measured by prothrombin time, activated partial thromboplastin time, and thrombin time) of both R- and S-warfarin. 7.4 Cytochrome P450 Based on in vitro and in vivo results, it is unlikely that co-administration of ARIMIDEX 1 mg will affect other drugs as a result of inhibition of cytochrome P450 [see Clinical Pharmacology ( 12.3 )] .
Use in specific populations
• Lactation: Do not breastfeed. ( 8.2 )
• Females and Males of Reproductive Potential: Verify pregnancy status prior to initiation of ARIMIDEX. ( 8.3 )
• Pediatric patients: Efficacy has not been demonstrated for pubertal boys of adolescent age with gynecomastia or girls with McCune-Albright Syndrome and progressive precocious puberty. ( 8.4 ) 8.1 Pregnancy Risk Summary Based on findings from animal studies and its mechanism of action, ARIMIDEX may cause fetal harm when administered to a pregnant woman [see Clinical Pharmacology ( 12.1 )] . There are no studies of ARIMIDEX use in pregnant women. 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/m 2 basis. Advise pregnant women and females of reproductive potential of the potential risk to a fetus. The background risk of major birth defects and miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Animal Data In animal reproduction studies, pregnant rats and rabbits received anastrozole during organogenesis at doses equal to or greater than 0.1 and 0.02 mg/kg/day, respectively, (about 1 and 1/3 the recommended human dose on a mg/m 2 basis, respectively). In both species, anastrozole crossed the placenta, and there was increased pregnancy loss (increased pre- and/or post-implantation loss, increased resorption, and decreased numbers of live fetuses). In rats, these effects were dose related, and placental weights were significantly increased at doses equal to or greater than 0.1 mg/kg/day. Fetotoxicity, including delayed fetal development (i.e., incomplete ossification and depressed fetal body weights), occurred in rats at anastrozole doses of 1 mg/kg/day that produced peak plasma levels 19 times higher than serum levels in humans at the therapeutic dose (AUC 0-24hr 9 times higher). In rabbits, anastrozole caused pregnancy failure at doses equal to or greater than 1.0 mg/kg/day (about 16 times the recommended human dose on a mg/m 2 basis). 8.2 Lactation Risk Summary There are no data on the presence of anastrozole or its metabolites in human milk, or its effects on the breast-fed child or on milk production. Because many drugs are excreted in human milk and because of the tumorigenicity shown for anastrozole in animal studies, or the potential for serious adverse reactions in the breast-fed child from ARIMIDEX, advise lactating women not to breastfeed during treatment with ARIMIDEX and for 2 weeks after the last dose. 8.3 Females and Males of Reproductive Potential Pregnancy Testing Verify the pregnancy status of females of reproductive potential prior to initiation of ARIMIDEX. Contraception Females Based on animal studies, ARIMIDEX can cause fetal harm when administered to a pregnant woman [see Use in Specific Populations ( 8.1 )] . Advise females of reproductive potential to use effective contraception during treatment with ARIMIDEX and for at least 3 weeks after the last dose. Infertility Females Based on studies in female animals, ARIMIDEX may impair fertility in females of reproductive potential [see Nonclinical Toxicology ( 13.1 )] . 8.4 Pediatric Use Clinical studies in pediatric patients included a placebo-controlled trial in pubertal boys of adolescent age with gynecomastia and a single-arm trial in girls with McCune-Albright Syndrome and progressive precocious puberty. The efficacy of ARIMIDEX in the treatment of pubertal gynecomastia in adolescent boys and in the treatment of precocious puberty in girls with McCune-Albright Syndrome has not been demonstrated. Gynecomastia Study A randomized, double-blind, placebo-controlled, multi-center study enrolled 80 boys with pubertal gynecomastia aged 11 to 18 years. Patients were randomized to a daily regimen of either ARIMIDEX 1 mg or placebo. After 6 months of treatment there was no statistically significant difference in the percentage of patients who experienced a ≥50% reduction in gynecomastia (primary efficacy analysis). Secondary efficacy analyses (absolute change in breast volume, the percentage of patients who had any reduction in the calculated volume of gynecomastia, breast pain resolution) were consistent with the primary efficacy analysis. Serum estradiol concentrations at Month 6 of treatment were reduced by 15.4% in the ARIMIDEX group and 4.5% in the placebo group. Adverse reactions that were assessed as treatment-related by the investigators occurred in 16.3% of the ARIMIDEX-treated patients and 8.1% of the placebo-treated patients with the most frequent being acne (7% ARIMIDEX and 2.7% placebo) and headache (7% ARIMIDEX and 0% placebo); all other adverse reactions showed small differences between treatment groups. One patient treated with ARIMIDEX discontinued the trial because of testicular enlargement. The mean baseline-subtracted change in testicular volume after 6 months of treatment was + 6.6 ± 7.9 cm 3 in the ARIMIDEX-treated patients and + 5.2 ± 8.0 cm 3 in the placebo group. McCune-Albright Syndrome Study A multi-center, single-arm, open-label study was conducted in 28 girls with McCune-Albright Syndrome and progressive precocious puberty aged 2 to <10 years. All patients received a 1 mg daily dose of ARIMIDEX. The trial duration was 12 months. Patients were enrolled on the basis of a diagnosis of typical (27/28) or atypical (1/27) McCune-Albright Syndrome, precocious puberty, history of vaginal bleeding, and/or advanced bone age.
Pregnancy
8.1 Pregnancy Risk Summary Based on findings from animal studies and its mechanism of action, ARIMIDEX may cause fetal harm when administered to a pregnant woman [see Clinical Pharmacology ( 12.1 )] . There are no studies of ARIMIDEX use in pregnant women. 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/m 2 basis. Advise pregnant women and females of reproductive potential of the potential risk to a fetus. The background risk of major birth defects and miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Animal Data In animal reproduction studies, pregnant rats and rabbits received anastrozole during organogenesis at doses equal to or greater than 0.1 and 0.02 mg/kg/day, respectively, (about 1 and 1/3 the recommended human dose on a mg/m 2 basis, respectively). In both species, anastrozole crossed the placenta, and there was increased pregnancy loss (increased pre- and/or post-implantation loss, increased resorption, and decreased numbers of live fetuses). In rats, these effects were dose related, and placental weights were significantly increased at doses equal to or greater than 0.1 mg/kg/day. Fetotoxicity, including delayed fetal development (i.e., incomplete ossification and depressed fetal body weights), occurred in rats at anastrozole doses of 1 mg/kg/day that produced peak plasma levels 19 times higher than serum levels in humans at the therapeutic dose (AUC 0-24hr 9 times higher). In rabbits, anastrozole caused pregnancy failure at doses equal to or greater than 1.0 mg/kg/day (about 16 times the recommended human dose on a mg/m 2 basis).
Pediatric use
8.4 Pediatric Use Clinical studies in pediatric patients included a placebo-controlled trial in pubertal boys of adolescent age with gynecomastia and a single-arm trial in girls with McCune-Albright Syndrome and progressive precocious puberty. The efficacy of ARIMIDEX in the treatment of pubertal gynecomastia in adolescent boys and in the treatment of precocious puberty in girls with McCune-Albright Syndrome has not been demonstrated. Gynecomastia Study A randomized, double-blind, placebo-controlled, multi-center study enrolled 80 boys with pubertal gynecomastia aged 11 to 18 years. Patients were randomized to a daily regimen of either ARIMIDEX 1 mg or placebo. After 6 months of treatment there was no statistically significant difference in the percentage of patients who experienced a ≥50% reduction in gynecomastia (primary efficacy analysis). Secondary efficacy analyses (absolute change in breast volume, the percentage of patients who had any reduction in the calculated volume of gynecomastia, breast pain resolution) were consistent with the primary efficacy analysis. Serum estradiol concentrations at Month 6 of treatment were reduced by 15.4% in the ARIMIDEX group and 4.5% in the placebo group. Adverse reactions that were assessed as treatment-related by the investigators occurred in 16.3% of the ARIMIDEX-treated patients and 8.1% of the placebo-treated patients with the most frequent being acne (7% ARIMIDEX and 2.7% placebo) and headache (7% ARIMIDEX and 0% placebo); all other adverse reactions showed small differences between treatment groups. One patient treated with ARIMIDEX discontinued the trial because of testicular enlargement. The mean baseline-subtracted change in testicular volume after 6 months of treatment was + 6.6 ± 7.9 cm 3 in the ARIMIDEX-treated patients and + 5.2 ± 8.0 cm 3 in the placebo group. McCune-Albright Syndrome Study A multi-center, single-arm, open-label study was conducted in 28 girls with McCune-Albright Syndrome and progressive precocious puberty aged 2 to <10 years. All patients received a 1 mg daily dose of ARIMIDEX. The trial duration was 12 months. Patients were enrolled on the basis of a diagnosis of typical (27/28) or atypical (1/27) McCune-Albright Syndrome, precocious puberty, history of vaginal bleeding, and/or advanced bone age. Patients’ baseline characteristics included the following: a mean chronological age of 5.9 ± 2.0 years, a mean bone age of 8.6 ± 2.6 years, a mean growth rate of 7.9 ± 2.9 cm/year and a mean Tanner stage for breast of 2.7 ± 0.81. Compared to pre-treatment data there were no on-treatment statistically significant reductions in the frequency of vaginal bleeding days, or in the rate of increase of bone age (defined as a ratio between the change in bone age over the change of chronological age). There were no clinically significant changes in Tanner staging, mean ovarian volume, mean uterine volume and mean predicted adult height. A small but statistically significant reduction of growth rate from 7.9 ± 2.9 cm/year to 6.5 ± 2.8 cm/year was observed but the absence of a control group precludes attribution of this effect to treatment or to other confounding factors such as variations in endogenous estrogen levels commonly seen in McCune-Albright Syndrome patients. Five patients (18%) experienced adverse reactions that were considered possibly related to ARIMIDEX. These were nausea, acne, pain in an extremity, increased alanine transaminase and aspartate transaminase, and allergic dermatitis. Pharmacokinetics in Pediatric Patients Following 1 mg once daily multiple administration in pediatric patients, the mean time to reach the maximum anastrozole concentration was 1 hr. The mean (range) disposition parameters of anastrozole in pediatric patients were described by a CL/F of 1.54 L/h (0.77-4.53 L/h) and V/F of 98.4 L (50.7-330.0 L). The terminal elimination half-life was 46.8 h, which was similar to that observed in postmenopausal women treated with anastrozole for breast cancer. Based on a population pharmacokinetic analysis, the pharmacokinetics of anastrozole was similar in boys with pubertal gynecomastia and girls with McCune-Albright Syndrome.
Geriatric use
8.5 Geriatric Use In studies 0030 and 0027, about 50% of patients were 65 or older. Patients ≥ 65 years of age had moderately better tumor response and time to tumor progression than patients < 65 years of age regardless of randomized treatment. In studies 0004 and 0005, 50% of patients were 65 or older. Response rates and time to progression were similar for the over 65 and younger patients. In the ATAC study, 45% of patients were 65 years of age or older. The efficacy of ARIMIDEX compared to tamoxifen in patients who were 65 years or older (N=1413 for ARIMIDEX and N=1410 for tamoxifen, the hazard ratio for disease-free survival was 0.93 [95% CI: 0.80, 1.08]) was less than efficacy observed in patients who were less than 65 years of age (N=1712 for ARIMIDEX and N=1706 for tamoxifen, the hazard ratio for disease-free survival was 0.79 [95% CI: 0.67, 0.94]). The pharmacokinetics of anastrozole are not affected by age.
Overdosage
Clinical trials have been conducted with ARIMIDEX, up to 60 mg in a single dose given to healthy male volunteers and up to 10 mg daily given to postmenopausal women with advanced breast cancer; these dosages were tolerated. A single dose of ARIMIDEX that results in life-threatening symptoms has not been established. There is no specific antidote to overdosage and treatment must be symptomatic. In the management of an overdose, consider that multiple agents may have been taken. Vomiting may be induced if the patient is alert. Dialysis may be helpful because ARIMIDEX is not highly protein bound. General supportive care, including frequent monitoring of vital signs and close observation of the patient, is indicated.
Description
(anastrozole) tablets for oral administration contain 1 mg of anastrozole, a non-steroidal aromatase inhibitor. It is chemically described as 1,3-Benzenediacetonitrile, a, a, a', a'-tetramethyl-5-(1H-1,2,4-triazol-1-ylmethyl). Its molecular formula is C 17 H 19 N 5 and its structural formula is: Anastrozole is an off-white powder with a molecular weight of 293.4. Anastrozole has moderate aqueous solubility (0.5 mg/mL at 25°C); solubility is independent of pH in the physiological range. Anastrozole is freely soluble in methanol, acetone, ethanol, and tetrahydrofuran, and very soluble in acetonitrile. Each tablet contains as inactive ingredients: lactose, magnesium stearate, hypromellose, polyethylene glycol, povidone, sodium starch glycolate, and titanium dioxide. Chemical Structure for anastrozole
Mechanism of action
12.1 Mechanism of Action The growth of many cancers of the breast is stimulated or maintained by estrogens. In postmenopausal women, estrogens are mainly derived from the action of the aromatase enzyme, which converts adrenal androgens (primarily androstenedione and testosterone) to estrone and estradiol. The suppression of estrogen biosynthesis in peripheral tissues and in the cancer tissue itself can therefore be achieved by specifically inhibiting the aromatase enzyme. Anastrozole is a selective non-steroidal aromatase inhibitor. It significantly lowers serum estradiol concentrations and has no detectable effect on formation of adrenal corticosteroids or aldosterone.
How supplied
(anastrozole) Tablets, 1 mg are supplied in bottles of 30 tablets (NDC 62559-670-30). Storage Store at controlled room temperature, 20 to 25°C (68 to 77°F) [see USP].
Patient information
See FDA approved patient labeling (Patient Information). Hypersensitivity Reactions Inform patients of the possibility of serious allergic reactions with swelling of the face, lips, tongue and/or throat (angioedema) which may cause difficulty in swallowing and/or breathing and to seek medical attention immediately [see Contraindications ( 4 )] . Ischemic Cardiovascular Events Patients with pre-existing ischemic heart disease should be informed that an increased incidence of cardiovascular events has been observed with ARIMIDEX use compared to tamoxifen use. Advise patients if new or worsening chest pain or shortness of breath occurs to seek medical attention immediately [see Warnings and Precautions ( 5.1 )] . Bone Effects Inform patients that ARIMIDEX lowers the level of estrogen. This may lead to a loss of the mineral content of bones, which might decrease bone strength. A possible consequence of decreased mineral content of bones is an increase in the risk of fractures [see Warnings and Precautions ( 5.2 )] . Cholesterol Inform patients that an increased level of cholesterol might be seen while receiving ARIMIDEX [see Warnings and Precautions ( 5.3 )] . Carpal Tunnel Patients should be informed that if they experience tickling, tingling, or numbness they should notify their health care provider [see Adverse Reactions ( 6.1 )] . Tamoxifen Patients should be advised not to take ARIMIDEX with Tamoxifen [see Clinical Studies ( 14.1 )] . Missed Doses Inform patients that if they miss a dose, take it as soon as they remember. If it is almost time for their next dose, skip the missed dose and take the next regularly scheduled dose. Patients should not take two doses at the same time. Embryo-Fetal Toxicity Advise females of reproductive potential of the potential risk to a fetus and to use effective contraception during ARIMIDEX therapy and for at least 3 weeks after the last dose. Advise females to contact their healthcare provider if they become pregnant, or if pregnancy is suspected, during treatment with ARMIDEX [see Warning and Precautions ( 5.4 ) and Use in Specific Populations ( 8.1 , 8.3 )] . Lactation Advise women not to breastfeed during ARIMIDEX treatment and for at least 2 weeks after the last dose [see Use in Specific Population ( 8.2 )] . Distributed by: ANI Pharmaceuticals, Inc. Baudette, MN 56623 ARIMIDEX is a registered trademark of the AstraZeneca group of companies and is licensed to ANI Pharmaceuticals, Inc. ani
Label text from the FDA structured product label by ANI Pharmaceuticals, Inc. (revised Mar 2, 2026). Long sections are shortened; the complete label is on DailyMed.
Active ingredients
- Anastrozole in 1 product
Arimidex NDC products (1)
| NDC | Strength & form | Labeler | Type |
|---|---|---|---|
| 62559-670 | Anastrozole 1 mg/1 Tablet | ANI Pharmaceuticals, Inc. | NDA |
Frequently asked questions
What is Arimidex used for?
1 INDICATIONS AND USAGE ARIMIDEX is an aromatase inhibitor indicated for: • Adjuvant treatment of postmenopausal women with hormone receptor-positive early breast cancer ( 1.1 ) • First-line treatment of postmenopausal women with hormone receptor-positive or hormone receptor-unknown locally advanced or metastatic breast cancer ( 1.2 ) • Treatment of advanced breast cancer in postmenopausal women…
What are the side effects of Arimidex?
Serious adverse reactions with ARIMIDEX occurring in less than 1 in 10,000 patients, are: 1) skin reactions such as lesions, ulcers, or blisters; 2) allergic reactions with swelling of the face, lips, tongue, and/or throat. This may cause difficulty in swallowing and/or breathing; and 3) changes in blood tests of the liver function, including inflammation of the liver with symptoms that may… See the full label for the complete list.
Who makes Arimidex?
Arimidex is listed by 1 labeler in the FDA NDC directory, including ANI Pharmaceuticals, Inc..