anastrozole
Anastrozole (Arimidex) is one of the first-choice options used for early or metastatic breast cancer, but it's only FDA approved to treat women who have gone through menopause (postmenopausal). It comes as an oral tablet that's typically taken daily. And common side effects include hot flashes, tiredness, nausea, and vomiting. Anastrozole (Arimidex) is available both as a generic medication and under the brand name Arimidex.
What is Anastrozole (Arimidex)?
What is Anastrozole (Arimidex) used for?
Early stage HR+ breast cancer in postmenopausal women
Advanced or metastatic HR+ breast cancer in postmenopausal women
Advanced breast cancer in postmenopausal women that's getting worse after treatment with tamoxifen
How Anastrozole (Arimidex) works
Anastrozole (Arimidex) is an aromatase inhibitor. Aromatase is a protein in your body that helps change other hormones into estrogen. By blocking aromatase, anastrozole (Arimidex) lowers the amount of estrogen in your body. This is helpful since estrogen can fuel the growth of certain types of breast cancer cells. Without estrogen, cancer cells won’t have the “fuel” they need to grow or spread.
Drug Facts
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What are the side effects of Anastrozole (Arimidex)?
Common Side Effects
- Hot flashes (36%)
- Muscle and joint problems (36%)
- Tiredness (19%)
- Changes in mood (19%)
- Nausea and vomiting (13%)
- Bone fractures (10%)
- Cataracts (6%)
- Vaginal bleeding (5%)
- Nausea and vomiting (34%)
- Hot flashes (26%)
- Depression (5%)
- Nausea and vomiting (29%)
- Hot flashes (13%)
- Swelling in the body (7%)
Other Side Effects
- Headache
- Blood clots
- Vaginal dryness
- Weight gain
- Constipation
- Trouble sleeping
- Dizziness
- Cough
- Back pain
- Dry mouth
- Rash
Serious Side Effects
- Heart disease: chest pain, shortness of breath, lightheadedness
Source: DailyMed
More on Anastrozole (Arimidex) side effects
The following side effects have also been reported
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
More common
Blurred vision
bone pain
chest pain or discomfort
dizziness
headache
nervousness
pounding in the ears
slow or fast heartbeat
swelling of the feet or lower legs
Less common
Arm, back, or jaw pain
chest tightness or heaviness
chills
cough producing mucus
difficult or painful urination
difficulty breathing
dizziness, severe
headache, continuing
hoarseness
increased blood pressure
lower back or side pain
pain, tenderness, bluish color, or swelling of the foot or leg
sweating
unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness
vaginal bleeding (unexpected and heavy)
Incidence not known
Blistering, peeling, or loosening of the skin
confusion
dark urine
difficulty swallowing
general tiredness and weakness
hives or welts, itching, skin rash
incoherent speech
increased urination
joint or muscle pain
large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or genitals
light-colored stools
loss of appetite
metallic taste
muscle weakness
puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
red skin lesions, often with a purple center
red, irritated eyes
sores, ulcers, or white spots in the mouth or on the lips
stomach pain
thirst
upper right abdominal pain
vomiting
yellow eyes and skin
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
More common
Back pain
belching
body aches or pain
congestion
decrease in height
feeling of warmth
flushing or redness of the skin, especially on the face and neck
increased appetite
indigestion
lack or loss of strength
mood or mental changes
pain in the back, ribs, arms, or legs
pain, general
pelvic pain
stomach discomfort or upset
tender, swollen glands in the neck
trouble in swallowing
voice changes
Less common
breast pain
dryness of the vagina
general feeling of discomfort or illness
joint stiffness
loss of hair
numbness or tingling of the hands or feet
shivering
sleepiness
trouble sleeping
Incidence not known
Difficulty in moving
muscle cramps or stiffness
swollen joints
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Pros and cons of Anastrozole (Arimidex)
Pros
Oral tablet that you only need to take once a day
Can be taken with or without food
Available as a lower-cost generic version
Cons
Only FDA approved for breast cancer in postmenopausal women
Can cause menopausal symptoms, such as hot flashes
Can weaken your bones and raise your risk for fractures
Pharmacist tips for Anastrozole (Arimidex)
Anastrozole (Arimidex) can cause side effects similar to menopausal symptoms, such as hot flashes. If these side effects become bothersome, inform your provider who can suggest ways to manage them safely.
Anastrozole (Arimidex) can weaken your bones, making them more prone to fractures. Your provider might recommend that you take calcium or vitamin D while taking anastrozole (Arimidex) to strengthen your bones.
Anastrozole (Arimidex) might raise cholesterol levels in your blood. If your cholesterol gets too high, it can lead to serious heart disease. Regular blood tests might be necessary to monitor your cholesterol levels to make sure they stay within a healthy range.
Avoid taking any medications that contain estrogen while taking anastrozole (Arimidex). This is because anastrozole (Arimidex) works to lower estrogen levels, and taking extra estrogen can cause it to not work as well.
Frequently asked questions about Anastrozole (Arimidex)
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What are the risks and warnings for Anastrozole (Arimidex)?
Anastrozole (Arimidex) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Heart disease
Risk factors: History of heart disease
Anastrozole (Arimidex) can raise your risk for heart disease, especially if you already have a history of heart disease. Get medical help right away if you start to have chest pain or feel out of breath while taking anastrozole (Arimidex).
Bone thinning and weakness
Over time, anastrozole (Arimidex) can weaken your bones, which can put you at a higher risk for fractures, especially in your spine, hip, or wrist area. This is because anastrozole (Arimidex) works by lowering estrogen which is important in maintaining bone strength. Your provider might recommend bone mineral density (BMD) testing before and during your treatment with this medication to ensure that your bones remain healthy. This testing helps monitor the strength and density of your bones throughout the course of treatment.
High cholesterol
Some people taking anastrozole (Arimidex) can develop high cholesterol levels. Too much cholesterol in the blood can clog up blood vessels, raising your risk of heart attacks or strokes. You might have routine blood work done while you are taking the medication to check your cholesterol levels. And remember a healthy diet and exercise can help to lower your cholesterol.
Harm to unborn baby
Anastrozole (Arimidex) can be harmful to an unborn baby. Even though most people taking this medication will have already undergone menopause (postmenopausal), some providers might recommend it off-label for women who haven't undergone menopause (premenopausal). If there is a possibility that you can still become pregnant, use birth control while taking anastrozole (Arimidex) and for at least 3 weeks after your last dose to prevent pregnancy.
Anastrozole (Arimidex) dosage forms
| Dosage | Quantity | Price as low as | Price per unit |
|---|---|---|---|
| 1mg | 12 tablets | $9.74 | $0.81 |
Typical dosing for Anastrozole (Arimidex)
The typical dose is 1 mg by mouth daily.
Interactions between Anastrozole (Arimidex) and other drugs
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.
How much does Anastrozole (Arimidex) cost?
What are alternatives to Anastrozole (Arimidex)?
Early stage HR+ breast cancer in postmenopausal women
Advanced or metastatic HR+ breast cancer in postmenopausal women
Advanced breast cancer in postmenopausal women that's getting worse after treatment with tamoxifen
Early breast cancer in postmenopausal women who've had 2 to 3 years of treatment with tamoxifen
Advanced breast cancer in postmenopausal women whose cancer has worsened following treatment with tamoxifen
Breast cancer in females who have already gone through menopause:
What is the latest news about Anastrozole (Arimidex)?
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References
Best studies we foundAmerican Cancer Society. (2021). Chemotherapy for Breast Cancer.
American Cancer Society. (2023). Hormone Therapy for Breast Cancer in Men.
American Cancer Society. (2023). Hormone Therapy for Breast Cancer.
Breckenridge Pharmaceutical, Inc. (2023). ANASTROZOLE tablet [package insert]. DailyMed.
Eastell, R., et al. (2016). Effect of Anastrozole on Bone Mineral Density: 5-Year Results From the Anastrozole, Tamoxifen, Alone or in Combination Trial 18233230. Journal of Clinical Oncology.
Kligman, L., et al. (2010). Management of hot flashes in women with breast cancer. Current Oncology.
Makari-Judson, G., et al. (2014). Weight gain following breast cancer diagnosis: Implication and proposed mechanisms. World Journal of Clinical Oncology.
MedlinePlus. (2023). Bone mineral density test.
National Cancer Institute. (2021). Hot Flashes and Night Sweats (PDQ®)–Patient Version.
National Comprehensive Cancer Foundation. (2023). Metastatic breast cancer.
Pistelli, M., et al. (2018). Aromatase inhibitors in premenopausal women with breast cancer: the state of the art and future prospects. Current Oncology.
Punjani, N., et al. (2021). The Utilization and Impact of Aromatase Inhibitor Therapy in Men With Elevated Estradiol Levels on Testosterone Therapy. Sexual Medicine.
Sestak, I., et al. (2012). Weight change associated with anastrozole and tamoxifen treatment in postmenopausal women with or at high risk of developing breast cancer. bReast Cancer Research and Treatment.
Uscher, J. (2023). Hair loss. Breastcancer.org.
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