Treatment Name: Anastrozole (Arimidex®)
How does anastrozole work?
Anastrozole is designed to inhibit an enzyme (a protein) in your body called aromatase. Aromatase is responsible for helping produce estradiol (a type of estrogen). When anastrozole inhibits aromatase, less estrogen is produced in the body, and less estrogen is able to bind to the receptors on breast cancer cells. Since certain breast cancer cells need estrogen to grow and divide, aromatase is given to prevent estrogen from being made.
Goals of therapy:
Anastrozole is commonly taken to prevent the cancer from coming back in the same breast or the other breast.
- Usual starting dose: Anastrozole 1 mg oral tablet by mouth daily
Anastrozole is usually taken at home. Anastrozole therapy is often recommended to be taken for 3 to 5 years total. Anastrozole is only indicated for use in post-menopausal women and should not be used by pre-menopausal women.
In a multi-drug regimen, each medication has unique side effects. When these medicines are given together, drug-related side effects reported in clinical studies give the best estimate of what to expect. In clinical studies, the most commonly reported side effects with anastrozole are shown here. Side effects sometimes have percentage ranges [example 2 – 16%] because they differed between in clinical studies:
A note about side effect percentages
- Hot flashes (34%)
- Joint pain (28%)
- Fatigue (2 - 16%)
- Mood changes (16%)
- Nausea or vomiting (11%)
- Vaginal bleeding (5%)
- Cataracts (4%)
- Vaginal discharge (3%)
- Heart attack (3%)
- Stroke (1%)
- Blood clots (3%)
- Bone fractures (hip, spine, or wrist: 1 - 6%)
- Endometrial cancer (0.1% = 1 in 1,000 patients)
*Anastrozole was associated with less hot flashes, vaginal discharge or vaginal bleeding, stroke, blood clots, and endometrial cancer, compared to tamoxifen. However, joint problems as well as bone fractures of the spine and wrist (not hip) were more common with anastrozole than with tamoxifen.
Importantly, not all people who experience a side effect from Arimidex® (anastrozole) will experience it in the same way. It may be mild in some or severe in others, depending upon the individual. Everybody is different. Additionally, side effects may vary over time. For some, side effects may be a reason to delay or switch treatment, reduce the dose, or avoid future treatment with a certain medication altogether.
Side effects may be treatable when they occur or preventable by taking certain medications before they happen. When medications are taken to prevent a problem, this is known as prophylaxis, or "prophy" for short.
After starting treatment with Arimidex®, be sure to come back and watch all of the side effect videos shown below. Each of these videos contain valuable information about side effect management that will hopefully help you to both feel better and stay out of the hospital.
How often is monitoring needed?
Labs (blood tests) may be checked before treatment and every one to three months thereafter as needed. Labs often include: Complete Blood Count (CBC), Comprehensive Metabolic Panel (CMP), triglycerides, and blood cholesterol levels.
How often is imaging needed?
Imaging may be checked before treatment and as often as every two to six months during treatment. Imaging may include: bone scans, magnetic resonance imaging (MRI), and computerized tomography (CT) scans. DEXA (dual energy x-ray absorptiometry) scans may be performed to monitor your bone mineral density.
How might blood test results/imaging affect treatment?
Depending upon the results, your doctor may advise to continue anastrozole as planned, or delay or switch therapy.
- Ask your doctor before taking estrogen replacement therapy or other medications that contain estrogen as they may decrease the effectiveness of anastrozole
- A pharmacist should ALWAYS review your medication list to ensure that drug interactions are prevented or managed appropriately
- Clinical trials may exist for breast cancer. Ask your doctor if any studies are currently enrolling in your area. If not, go to clinicaltrials.gov to search for other centers offering study medications.
Patient Assistance & Co-payment Coverage
Patients under the age of 65 years, or those with private insurance plans:
If you have insurance and are looking for patient assistance or copay assistance for Anastrozole (Arimidex®), we have provided links that may help.
Visit our Patient Assistance page and click the links to various patient assistance programs for help paying for Anastrozole (Arimidex®). Depending upon your income, they may be able to help cover the cost of:
For Branded medications (may be available for generic medications too), check with the manufacturer to determine if a co-pay card is offered and if it could reduce your monthly copay.
- If you are uninsured, check with the manufacturer to determine if you are eligible to receive medication at no cost.
Medicare and Medicaid patients (Patients 65 years or older):
The clinic providing treatment will likely pre-authorize medications and immune therapies such as Anastrozole (Arimidex®) and are the best source to help you understand drug cost.
- Ask to speak with a patient assistance technician or financial counselor at the clinic or hospital administering this therapy.
What is Emotional Wellness?
Emotional wellness is having a positive outlook balanced with a realistic understanding of current life events. This requires both an awareness and acceptance of your emotions. It is with this knowledge that you can develop a plan to take the necessary actions to positively impact your life.
Emotional wellness uses an ongoing process to continually reflect on the stressors of life in a constructive manner to move forward and create happiness.
Because emotional wellness is deeply connected with physical, social, and spiritual wellness, pursuing it often becomes particularly difficult in times of major illness. Despite this difficulty, working toward emotional wellness has been connected to improved treatment outcomes and a higher likelihood of achieving goals of therapy.
Learn more about pursuing emotional wellness while receiving treatment with Anastrozole (Arimidex®)
What is Breast Cancer - early stage?
What is Early Stage Breast Cancer?
A disease of either the milk-producing glands known as lobules, or milk ducts, or other cells found in the breast. Early stage breast cancer may also affect the lymph nodes, but has not usually spread to other areas of the body. Breast cancer is the most common type of cancer diagnosed in women, but may rarely affect men as well. Breast cancer cells may have increased expression of estrogen receptors (ER positive or negative), progestin receptors (PR positive or negative), and/or HER-2 receptors (HER-2 positive or negative). The presence or lack of these receptors will help determine the most effective chemotherapy medications to give.
Genetic causes, such as the BRCA (pronounced "Bracka") mutation, significantly increase the risk of developing breast cancer. Other risk factors for breast cancer include family history of breast cancer, high fat diet, and obesity. The stage of breast cancer can vary at diagnosis and throughout treatment. Stages of breast cancer include I, II, III, and IV. The effectiveness of the treatment may depend upon the stage at diagnosis.
Types of breast cancer:
1. Hormone-receptor positive or negative (60 - 65% of patients)
- Estrogen Receptor positive (ER)+ or negative (ER)-
- Progestin Receptor positive (PR)+ or negative (PR)-
2. Hormone Epidermal growth factor Receptor-2 (HER-2) positive or negative (20 - 25% of patients)
- HER-2 + (positive)
- HER-2 - (negative)
3. Triple Negative (15 - 18% of patients)
NOTE: Treatment Options listed below are not all-inclusive. Other treatments may be available. ChemoExperts provides drug information and does not recommend any one treatment over another. Only your Doctor can choose which therapy is appropriate for you.
If you are interested in reading the clinical trials results, please click on references below:
1. Baum M, Budzar AU, Cuzick J, et al. Anastrozole alone or in combination with tamoxifen versus tamoxifen alone for adjuvant treatment of postmenopausal women with early breast cancer: first results of the ATAC randomised trial. Lancet. 2002;359:2131-2139.
2. Boccardo F, Rubagotti A, Puntoni M, et al. Switching to anastrozole versus continued tamoxifen treatment of early breast cancer: preliminary results of the Italian Tamoxifen Anastrozole Trial. J Clin Oncol. 2005;23:5138-5147.
What is a CBC?
A Complete Blood Count (CBC) is a frequently ordered blood test that tells clinicians the status of your: 1) White blood cell count, 2) Hemoglobin, and 3) Platelet count at the time the test was taken.
1) White blood cell count (WBC): is used to determine infection risk, or response to chemotherapy. Certain chemotherapy agents may harm our good infection-fighting cells. Sometimes chemotherapy may need to be delayed to allow these cells to recover.
2) Hemoglobin: is used to determine if someone is anemic. Anytime the hemoglobin is below 12 g/dL, the person is said to be anemic. Red blood cell transfusions, and sometimes iron can be given to restore the hemoglobin level, but anemia treatment should always aim at treating the underlying cause or condition.
3) Platelet count: is used to determine if the risk of bleeding is increased or if a platelet transfusion is required to prevent bleeding. Certain medications that increase bleeding risk, such as: aspirin, certain chemotherapy agents, and blood thinners, may need to be stopped temporarily until the platelet count is within a safe range.
What is a CMP?
A Comprehensive Metabolic Panel (CMP) is a frequently ordered blood test that tells clinicians the status of your: 1) Electrolytes & Acid/Base status, 2) Kidney function, 3) Liver function, 4) Blood sugar, and 5) Calcium at the time the test was taken. It is commonly used to monitor liver and kidney function when beginning new medications such as chemotherapy. A total of 14 tests are run simultaneously and are shown below.
Electrolytes & Acid/Base status:
1) Sodium, 2) Potassium, 3) Carbon dioxide, 4) Chloride
5) BUN (blood urea nitrogen), 6) Serum creatinine (Scr)
7) AST, 8) ALT, 9) Total bilirubin, 10) Alk Phos, 11) Albumin, 12) Total protein
13) Serum glucose
14) Serum calcium
What does Cure mean?The word “cure” means there are no cancer cells left in the body and cancer will never come back. Depending on the cancer type and stage, this may be the true goal of therapy. However, it is very difficult to prove all cancer cells are gone. Even though images, like X-rays and MRI’s, and blood tests may not show any signs of cancer, there can be a small amount of cancer cells still left in the body. Because of this, the word “remission” is used more often. This means there are no signs or symptoms of cancer. Patients in remission are followed closely for any signs of cancer returning. Sometimes, more chemotherapy may be given while in remission to prevent the cancer from coming back.
Doctors usually do not consider a patient “cured” until the chance of cancer returning is extremely low. If cancer does return, it usually happens within 5 years of having a remission. Because of this, doctors do not consider a patient cured unless the cancer has not come back within 5 years of remission. The five-year cutoff does not apply to all cancers.
A note about side effect percentagesThe number you see next to the percent sign (%) means how many people out of 100 are likely to experience this side effect.
For example, if the side effect is reported to occur in 8% of patients, this means that roughly 8 out of 100 people receiving this treatment will experience this side effect.