Arimidex

Name: Arimidex

Other uses for this medicine

Anastrozole is also sometimes used to prevent breast cancer in women who are at high risk of developing the disease. Talk to your doctor about the risks of using this drug for your condition.

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Do I need a prescription for anastrozole-oral?

Yes

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Reviewed on 10/3/2014 References REFERENCE: FDA Prescribing Information

Arimidex Overview

Arimidex is a prescription medication used to treat breast cancer in postmenopausal women. It specifically treats hormone receptor-positive tumors that are fueled by estrogen. Arimidex belongs to a group of drugs called aromatase inhibitors. These medications work by blocking an enzyme called aromatase that helps your body make estrogen. 

Arimidex comes in tablet form and is usually taken once a day, with or without food. Common side effects of Arimidex include hot flashes, weakness, joint pain, headache, and swelling.

Arimidex Drug Class

Arimidex is part of the drug class:

  • Aromatase inhibitors

Side Effects of Arimidex

Arimidex may cause serious side effects. See the "Arimidex Precautions" section.

Common side effects in women taking Arimidex include the following:

  • hot flashes
  • weakness
  • joint pain
  • carpal tunnel syndrome (tingling, pain, coldness, weakness in parts of the hand)
  • pain
  • sore throat
  • mood changes
  • high blood pressure
  • depression
  • nausea and vomiting
  • thinning of the hair (hair loss)
  • rash
  • back pain
  • sleep problems
  • bone pain
  • headache
  • swelling
  • increased cough
  • shortness of breath
  • lymphedema (build up of lymph fluid in the tissues of your affected arm)
  • trigger finger (a condition in which one of your fingers or your thumb catches in a bent position)

This is not a complete list of Arimidex side effects. Ask your doctor or pharmacist for more information.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Arimidex Interactions

Tell your doctor about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

  • tamoxifen. You should not take Arimidex if you take tamoxifen. Taking Arimidex with tamoxifen may lower the amount of Arimidex in your blood and may cause Arimidex not to work as well.
  • estrogen-containing medicines
  • hormone replacement therapy
  • birth control pills
  • estrogen creams
  • vaginal rings
  • vaginal suppositories 

This is not a complete list of Arimidex drug interactions. Ask your doctor or pharmacist for more information.

Arimidex Overdose

If you take too much Arimidex, call your healthcare provider or local Poison Control Center, or seek emergency medical attention right away.

If this medication is administered by a healthcare provider in a medical setting, it is unlikely that an overdose will occur. However, if overdose is suspected, seek emergency medical attention.

What is the most important information I should know about anastrozole?

Anastrozole may not work as well if you take it together with estrogen medication (such as hormone replacement therapy, estrogen creams, or birth control pills, injections, implants, skin patches, and vaginal rings).

Anastrozole may increase your risk of a stroke or blood clot. Call your doctor at once if you have sudden numbness or weakness, (especially on one side of the body), sudden severe headache, slurred speech, or problems with vision or balance.

Uses for Arimidex

Breast Cancer

Initial (primary) adjuvant therapy in postmenopausal women with early-stage hormone receptor-positive breast cancer.1 20 61

Sequential adjuvant therapy† following 2–3 years of adjuvant tamoxifen for early-stage hormone receptor-positive breast cancer in postmenopausal women.20

Extended adjuvant therapy† following 5 years of adjuvant tamoxifen for early-stage hormone receptor-positive breast cancer in postmenopausal women.54

Aromatase inhibitors are a treatment of choice for adjuvant hormonal therapy to lower risk of breast cancer recurrence in postmenopausal women with early-stage hormone receptor-positive breast cancer.20 61 An aromatase inhibitor-containing regimen is modestly more effective than tamoxifen alone.20 61

ASCO states that most postmenopausal women with early-stage hormone receptor-positive breast cancer should consider receiving an aromatase inhibitor during the course of adjuvant therapy, either as primary (initial) therapy or following 2–3 years of tamoxifen (sequential therapy), for a total of 5 years of adjuvant endocrine therapy.61 Data also support switching to an aromatase inhibitor following 5 years of adjuvant tamoxifen (extended adjuvant therapy).61 ASCO states that women who receive extended adjuvant therapy should receive tamoxifen for 5 years followed by an aromatase inhibitor for 3–5 years.61

Consider adverse effects, patient preference, and preexisting conditions when selecting an adjuvant regimen.61 Joint disorders (arthritis, arthrosis, arthralgia), fractures, and elevated cholesterol reported more frequently in patients receiving adjuvant anastrozole,1 whereas adverse gynecologic effects (endometrial cancer, vaginal discharge, vaginal bleeding), hot flushes, ischemic cerebrovascular events, and venous thromboembolism reported more frequently in those receiving adjuvant tamoxifen.1 50

First-line therapy for hormone receptor-positive (i.e., estrogen receptor-positive, progesterone receptor-positive, or both) or hormone receptor-unknown locally advanced or metastatic breast cancer in postmenopausal women.1 15 20

Second-line therapy for advanced breast cancer in postmenopausal women with disease progression following tamoxifen therapy.1 20 Usually ineffective in patients with estrogen receptor-negative breast cancer and those who fail tamoxifen therapy.1

Has been used for reduction in the incidence of breast cancer† in women at high risk for developing the disease.44

Arimidex Pharmacokinetics

Absorption

Bioavailability

Rapidly and well absorbed after oral administration, with peak plasma concentrations usually attained within 2 hours under fasting conditions.1

Steady-state plasma concentrations achieved in about 7 days.1

Onset

Serum estradiol concentrations reduced by approximately 70% within 24 hours of a 1-mg dose1 and by approximately 80% after 14 days of daily dosing.1

Duration

Suppression of serum estradiol concentrations maintained for up to 6 days after discontinuance of daily anastrozole administration.1

Food

Food reduces rate but does not affect extent of absorption.1

Distribution

Extent

Anastrozole crosses the placenta in animals;1 not known whether anastrozole crosses the placenta in humans.1

Not known whether anastrozole is distributed into milk.1

Plasma Protein Binding

40%.1

Elimination

Metabolism

Undergoes N-dealkylation, hydroxylation, and glucuronidation in the liver to multiple, pharmacologically inactive, metabolites.1

Elimination Route

Hepatic metabolism (85%) and renal excretion (10%).1

Half-life

Approximately 50 hours.1

Special Populations

No evidence of altered pharmacokinetics observed in women >80 years of age compared with women <50 years of age.1

Individuals with severe renal impairment (Clcr <30 mL/minute): Renal clearance decreased by approximately 50%, but total body clearance decreased by only 10%.1

Individuals with stable hepatic cirrhosis (related to alcohol abuse): Clearance reduced by approximately 30% compared with those with normal hepatic function;1 however, plasma concentrations within range compared with individuals with normal hepatic function.1

What do I need to tell my doctor BEFORE I take Arimidex?

  • If you have an allergy to anastrozole or any other part of Arimidex (anastrozole).
  • If you are allergic to any drugs like this one, any other drugs, foods, or other substances. Tell your doctor about the allergy and what signs you had, like rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other signs.
  • If you are pregnant or may be pregnant. Do not take this medicine if you are pregnant.
  • If you have not been through menopause or you are still able to have a baby.
  • If you are taking any of these drugs: Estrogen products or tamoxifen.

This is not a list of all drugs or health problems that interact with Arimidex.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take this medicine with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

How do I store and/or throw out Arimidex?

  • Store at room temperature.
  • Store in a dry place. Do not store in a bathroom.
  • Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
  • Check with your pharmacist about how to throw out unused drugs.

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.

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.

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.

Clinical Trials Experience

Adjuvant Therapy

Adverse reaction data for adjuvant therapy are based on the ATAC trial [see Clinical Studies]. 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*

Body system and adverse reactions by COSTART preferred term* ARIMIDEX 1 mg
(N§ = 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¶ 122 (4) 180 (6)
Vaginitis 125 (4) 158 (5)
* The combination arm was discontinued due to lack of efficacy benefit at 33 months of follow-up.
†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.
§ N=Number of patients receiving the treatment.
¶Vaginal Hemorrhage without further diagnosis.

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*

  ARIMIDEX
N=3092 (%)
Tamoxifen
N=3094 (%)
Odds-ratio 95% CI
Hot Flashes 1104 (36) 1264 (41) 0.80 0.73 -0.89
Musculoskeletal Events'1 1100 (36) 911 (29) 1.32 1.19 -1.47
Fatigue/Asthenia 575 (19) 544 (18) 1.07 0.94 -1.22
Mood Disturbances 597 (19) 554 (18) 1.10 0.97 - 1.25
Nausea and Vomiting 393 (13) 384 (12) 1.03 0.88 -1.19
All Fractures 315 (10) 209 (7) 1.57 1.30 -1.88
Fractures of Spine, Hip, or Wrist 133 (4) 91 (3) 1.48 1.13 -1.95
  Wrist/Colles’ fractures 67 (2) 50 (2)
  Spine fractures 43 (1) 22 (1)
  Hip fractures 28 (1) 26 (1)
Cataracts 182 (6) 213 (7) 0.85 0.69 -1.04
Vaginal Bleeding 167 (5) 317(10) 0.50 0.41 -0.61
Ischemic Cardiovascular Disease 127 (4) 104 (3) 1.23 0.95 -1.60
Vaginal Discharge 109 (4) 408 (13) 0.24 0.19 -0.30
Venous Thromboembolic events 87 (3) 140 (5) 0.61 0.47 -0.80
Deep Venous Thromboembolic Events 48 (2) 74 (2) 0.64 0.45 -0.93
Ischemic Cerebrovascular Event 62 (2) 88 (3) 0.70 0.50 -0.97
Endometrial Cancer* 4 (0.2) 13 (0.6) 0.31 0.10 -0.94
* Patients with multiple events in the same category are counted only once in that category.
†Refers to joint symptoms, including joint disorder, arthritis, arthrosis and arthralgia.
‡ Percentages calculated based upon the numbers of patients with an intact uterus at baseline

Ischemic Cardiovascular Events

Between treatment arms in the overall population of 6186 patients, there was no statistical difference in ischemic cardiovascular events (4% ARIMIDEX vs. 3% tamoxifen).

In the overall population, angina pectoris was reported in 71/3092 (2.3%) patients in the ARIMIDEX arm and 51/3094 (1.6%) patients in the tamoxifen arm; myocardial infarction was reported in 37/3092 (1.2%) patients in the ARIMIDEX arm and 34/3094 (1.1%) patients in the tamoxifen arm.

In women with pre-existing ischemic heart disease 465/6186 (7.5%), the incidence of ischemic cardiovascular events was 17% in patients on ARIMIDEX and 10% in patients on tamoxifen. In this patient population, angina pectoris was reported in 25/216 (11.6%) patients receiving ARIMIDEX and 13/249 (5.2%) patients receiving tamoxifen; myocardial infarction was reported in 2/216 (0.9%) patients receiving ARIMIDEX and 8/249 (3.2%) patients receiving tamoxifen.

Bone Mineral Density Findings

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.

Because ARIMIDEX lowers circulating estrogen levels it may cause a reduction in bone mineral density.

A post-marketing trial assessed the combined effects of ARIMIDEX and the bisphosphonate risedronate on changes from baseline in BMD and markers of bone resorption and formation in postmenopausal women with hormone receptor-positive early breast cancer. All patients received calcium and vitamin D supplementation. At 12 months, small reductions in lumbar spine bone mineral density were noted in patients not receiving bisphosphonates. Bisphosphonate treatment preserved bone density in most patients at risk of fracture.

Postmenopausal women with early breast cancer scheduled to be treated with ARIMIDEX should have their bone status managed according to treatment guidelines already available for postmenopausal women at similar risk of fragility fracture.

Cholesterol

During the ATAC trial, more patients receiving ARIMIDEX were reported to have an elevated serum cholesterol compared to patients receiving tamoxifen (9% versus 3.5%, respectively).

A post-marketing trial also evaluated any potential effects of ARIMIDEX on lipid profile. In the primary analysis population for lipids (ARIMIDEX alone), there was no clinically significant change in LDL-C from baseline to 12 months and HDL-C from baseline to 12 months.

In secondary population for lipids (ARIMIDEX+risedronate), there also was no clinically significant change in LDL-C and HDL-C from baseline to 12 months.

In both populations for lipids, there was no clinically significant difference in total cholesterol (TC) or serum triglycerides (TG) at 12 months compared with baseline.

In this trial, treatment for 12 months with ARIMIDEX alone had a neutral effect on lipid profile. Combination treatment with ARIMIDEX and risedronate also had a neutral effect on lipid profile.

The trial provides evidence that postmenopausal women with early breast cancer scheduled to be treated with ARIMIDEX should be managed using the current National Cholesterol Education Program guidelines for cardiovascular risk-based management of individual patients with LDL elevations.

Other Adverse Reactions

Patients receiving ARIMIDEX had an increase in joint disorders (including arthritis, arthrosis and arthralgia) compared with patients receiving tamoxifen. Patients receiving ARIMIDEX had an increase in the incidence of all fractures (specifically fractures of spine, hip and wrist) [315 (10%)] compared with patients receiving tamoxifen [209 (7%)].

Patients receiving ARIMIDEX had a higher incidence of carpal tunnel syndrome [78 (2.5%)] compared with patients receiving tamoxifen [22 (0.7%)].

Vaginal bleeding occurred more frequently in the tamoxifen-treated patients versus the ARIMIDEX-treated patients 317 (10%) versus 167 (5%), respectively.

Patients receiving ARIMIDEX had a lower incidence of hot flashes, vaginal bleeding, vaginal discharge, endometrial cancer, venous thromboembolic events and ischemic cerebrovascular events compared with patients receiving tamoxifen.

10-Year Median Follow-Up Safety Results From The ATAC Trial

Results are consistent with the previous analyses.

Serious adverse reactions were similar between ARIMIDEX (50%) and tamoxifen (51%).

  • Cardiovascular events were consistent with the known safety profiles of ARIMIDEX and tamoxifen.
  • The cumulative incidences of all first fractures (both serious and non-serious, occurring either during or after treatment) was higher in the ARIMIDEX group (15%) compared to the tamoxifen group (11%). This increased first fracture rate during treatment did not continue in the post-treatment follow-up period.
  • The cumulative incidence of new primary cancers was similar in the ARIMIDEX group (13.7%) compared to the tamoxifen group (13.9%). Consistent with the previous analyses, endometrial cancer was higher in the tamoxifen group (0.8%) compared to the ARIMIDEX group (0.2%).
  • The overall number of deaths (during or off-trial treatment) was similar between the treatment groups. There were more deaths related to breast cancer in the tamoxifen than in the ARIMIDEX treatment group.
First-Line Therapy

Adverse reactions occurring with an incidence of at least 5% in either treatment group of trials 0030 and 0027 during or within 2 weeks of the end of treatment are shown in Table 3.

Table 3 : Adverse Reactions Occurring with an Incidence of at Least 5% in Trials 0030 and 0027

Body system
Adverse Reaction*
Number (%) of subjects
ARIMIDEX (N=506) Tamoxifen (N=511)
Whole body
Asthenia 83 (16) 81(16)
Pain 70(14) 73 (14)
Back pain 60(12) 68 (13)
Headache 47 (9) 40 (8)
Abdominal pain 40 (8) 38 (7)
Chest pain 37 (7) 37 (7)
Flu syndrome 35 (7) 30 (6)
Pelvic pain 23 (5) 30 (6)
Cardiovascular
Vasodilation 128 (25) 106 (21)
Hypertension 25 (5) 36 (7)
Digestive
Nausea 94 (19) 106 (21)
Constipation 47 (9) 66 (13)
Diarrhea 40 (8) 33 (6)
Vomiting 38 (8) 36 (7)
Anorexia 26 (5) 46 (9)
Metabolic and Nutritional
Peripheral edema 51 (10) 41 (8)
Musculoskeletal
Bone pain 54 (11) 52 (10)
Nervous
Dizziness 30 (6) 22 (4)
Insomnia 30 (6) 38 (7)
Depression 23 (5) 32 (6)
Hypertonia 16 (3) 26 (5)
Respiratory
Cough increased 55 (11) 52 (10)
Dyspnea 51 (10) 47 (9)
Pharyngitis 49 (10) 68 (13)
Skin and appendages
Rash 38 (8) 34 (8)
Urogenital
Leukorrhea 9 (2) 31 (6)
* A patient may have had more than 1 adverse event.

Less frequent adverse experiences reported in patients receiving ARIMIDEX l mg in either Trial 0030 or Trial 0027 were similar to those reported for second-line therapy.

Based on results from second-line therapy and the established safety profile of tamoxifen, the incidences of 9 pre-specified adverse event categories potentially causally related to one or both of the therapies because of their pharmacology were statistically analyzed. No significant differences were seen between treatment groups.

Table 4 : Number of Patients with Pre-specified Adverse Reactions in Trials 0030 and 0027

Adverse Reaction* Number (n) and Percentage of Patients
ARIMIDEX 1 mg
(N=506)
n (%)
NOLVADEX 20 mg
(N=511)
n (%)
Depression 23 (5) 32 (6)
Tumor Flare 15 (3) 18 (4)
Thromboembolic Disease† 18 (4) 33 (6)
Venous† 5 15
Coronary and Cerebral‡ 13 19
Gastrointestinal Disturbance 170 (34) 196 (38)
Hot Flushes 134 (26) 118 (23)
Vaginal Dryness 9 (2) 3 (1)
Lethargy 6 (1) 15 (3)
Vaginal Bleeding 5 (1) 11 (2)
Weight Gain 11 (2) 8 (2)
* A patient may have had more than 1 adverse reaction.
†Includes pulmonary embolus, thrombophlebitis, retinal vein thrombosis.
‡ Includes myocardial infarction, myocardial ischemia, angina pectoris, cerebrovascular accident, cerebral ischemia and cerebral infarct.

Second-Line Therapy

ARIMIDEX was tolerated in two controlled clinical trials (i.e., Trials 0004 and 0005), with less than 3.3% of the ARIMIDEX-treated patients and 4.0% of the megestrol acetate-treated patients withdrawing due to an adverse reaction.

The principal adverse reaction more common with ARIMIDEX than megestrol acetate was diarrhea. Adverse reactions reported in greater than 5% of the patients in any of the treatment groups in these two controlled clinical trials, regardless of causality, are presented below:

Table 5 :Number (N) and Percentage of Patients with Adverse Reactions in Trials 0004 and 0005

Adverse Reaction* ARIMIDEX 1 mg
(N=262)
ARIMIDEX 10 mg
(N=246)
Megestrol Acetate 160 mg
(N=253)
n % n % n %
Asthenia 42 (16) 33 (13) 47 (19)
Nausea 41 (16) 48 (20) 28 (11)
Headache 34 (13) 44 (18) 24 (9)
Hot Flashes 32 (12) 29 (11) 21 (8)
Pain 28 (11) 38 (15) 29 (11)
Back Pain 28 (11) 26 (11) 19 (8)
Dyspnea 24 (9) 27 (11) 53 (21)
Vomiting 24 (9) 26 (11) 16 (6)
Cough Increased 22 (8) 18 (7) 19 (8)
Diarrhea 22 (8) 18 (7) 7 (3)
Constipation 18 (7) 18 (7) 21 (8)
Abdominal Pain 18 (7) 14 (6) 18 (7)
Anorexia 18 (7) 19 (8) 11 (4)
Bone Pain 17 (6) 26 (12) 19 (8)
Pharyngitis 16 (6) 23 (9) 15 (6)
Dizziness 16 (6) 12 (5) 15 (6)
Rash 15 (6) 15 (6) 19 (8)
Dry Mouth 15 (6) 11 (4) 13 (5)
Peripheral Edema 14 (5) 21 (9) 28 (11)
Pelvic Pain 14 (5) 17 (7) 13 (5)
Depression 14 (5) 6 (2) 5 (2)
Chest Pain 13 (5) 18 (7) 13 (5)
Paresthesia 12 (5) 15 (6) 9 (4)
Vaginal Hemorrhage 6 (2) 4 (2) 13 (5)
Weight Gain 4 (2) 9 (4) 30 (12)
Sweating 4 (2) 3 (1) 16 (6)
Increased Appetite 0 (0) 1 (0) 13 (5)
* A patient may have had more than one adverse reaction. Other less frequent (2% to 5%) adverse reactions reported in patients receiving ARIMIDEX l mg in either Trial 0004 or Trial 0005 are listed below. These adverse experiences are listed by body system and are in order of decreasing frequency within each body system regardless of assessed causality.

Body as a Whole: Flu syndrome; fever; neck pain; malaise; accidental injury; infection

Cardiovascular: Hypertension; thrombophlebitis

Hepatic: Gamma GT increased; SGOT increased; SGPT increased Hematologic: Anemia; leukopenia

Metabolic and Nutritional: Alkaline phosphatase increased; weight loss

Mean serum total cholesterol levels increased by 0.5 mmol/L among patients receiving ARIMIDEX. Increases in LDL cholesterol have been shown to contribute to these changes.

Musculoskeletal: Myalgia; arthralgia; pathological fracture

Nervous: Somnolence; confusion; insomnia; anxiety; nervousness

Respiratory: Sinusitis; bronchitis; rhinitis

Skin and Appendages: Hair thinning (alopecia); pruritus

Urogenital: Urinary tract infection; breast pain

The incidences of the following adverse reaction groups potentially causally related to one or both of the therapies because of their pharmacology, were statistically analyzed: weight gain, edema, thromboembolic disease, gastrointestinal disturbance, hot flushes, and vaginal dryness. These six groups, and the adverse reactions captured in the groups, were prospectively defined. The results are shown in the table below.

Table 6 : Number (n) and Percentage of Patients with Pre-specified Adverse Reactions in Trials 0004 and 0005

Adverse Reaction Group ARIMIDEX1 mg
(N=262)
ARIMIDEX10 mg
(N=246)
Megestrol Acetate160 mg
(N=253)
n (%) n (%) n (%)
Gastrointestinal Disturbance 77 (29) 81 (33) 54 (21)
Hot Flushes 33 (13) 29 (12) 35 (14)
Edema 19 (7) 28 (11) 35 (14)
Thromboembolic Disease 9 (3) 4 (2) 12 (5)
Vaginal Dryness 5 (2) 3 (1) 2 (1)
Weight Gain 4 (2) 10 (4) 30 (12)

Post-Marketing Experience

These adverse reactions are reported voluntarily from a population of uncertain size. Therefore, it is not always possible to estimate reliably their frequency or establish a causal relationship to drug exposure. The following have been reported in post-approval use of Arimidex:

  • Hepatobiliary events including increases in alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, gamma-GT, and bilirubin; hepatitis
  • Rash including cases of mucocutaneous disorders such as erythema multiforme and Stevens-Johnson syndrome
  • Cases of allergic reactions including angioedema, urticaria and anaphylaxis [see CONTRAINDICATIONS]
  • Myalgia, trigger finger and hypercalcemia (with or without an increase in parathyroid hormone)

Read the entire FDA prescribing information for Arimidex (Anastrozole)

Read More »

How should I take Arimidex?

Arimidex is usually taken once per day. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

You may take Arimidex with or without food.

You may need to keep taking this medication for up to 5 years. Follow your doctor's instructions.

Store at room temperature away from moisture and heat.

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