anastrozole
Anastrozole (Arimidex) is prescription oral medication used to treat certain types of breast cancer, including both early and advanced or metastatic stages. It's FDA approved only for postmenopausal women, or those who have already gone through menopause. This medication belongs to a class called aromatase inhibitors, which works by lowering estrogen levels in the body. You take one tablet by mouth once a day, with or without food. Common side effects include hot flashes, weakness, and joint pain.
What is Anastrozole (Arimidex)?
What is Anastrozole (Arimidex) used for?
- Early breast cancer (HR+) in postmenopausal women
- Advanced or metastatic breast cancer HR+ or HR unknown in postmenopausal women
- Advanced breast cancer in postmenopausal women whose cancer has worsened after treatment with tamoxifen
How Anastrozole (Arimidex) works
Anastrozole (Arimidex) is an aromatase inhibitor, meaning it blocks a protein in your body called aromatase. Aromatase helps make estrogen, a hormone that can cause some types of breast cancer to grow.
By blocking aromatase, anastrozole (Arimidex) lowers estrogen levels in your body. This helps slow down or stop the growth of breast cancer that depends on estrogen to grow.
Drug facts
More on Anastrozole (Arimidex) essentials
Side effects of Anastrozole (Arimidex)
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Common Side Effects
Early breast cancer:
- Hot flashes (36%)
- Muscle and joint problems (36%)
- Tiredness (19%)
- Changes in mood (19%)
- Nausea and vomiting (13%)
- Bone fractures (10%)
Advanced or metastatic breast cancer:
- Nausea and vomiting (34%)
- Hot flashes (26%)
Advanced breast cancer that's worsened after tamoxifen treatment:
- Nausea and vomiting (29%)
- Hot flashes (13%)
Less Common Side Effects
Early breast cancer:
- Cataracts
- Vaginal bleeding
- Vaginal discharge
Advanced or metastatic breast cancer:
- Depression
- Vaginal dryness
- Vaginal bleeding
- Tiredness
- Weight gain
Advanced breast cancer that's worsened after tamoxifen treatment:
- Swelling in the arms and legs
- Vaginal dryness
- Weight gain
Anastrozole (Arimidex) serious side effects
Contact your healthcare provider immediately if you experience any of the following.
- Heart disease: chest pain, shortness of breath, lightheadedness
More on Anastrozole (Arimidex) side effects
The following Anastrozole (Arimidex) 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.
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Pros and cons of Anastrozole (Arimidex)
Pros
- Oral tablet taken once a day
- Can be taken with or without food
- Helps reduce the risk of breast cancer coming back
Cons
- Only FDA approved to treat postmenopausal women
- Commonly causes hot flashes, joint pain, weakness
- Typically need to take it for at least 5 years
Pharmacist tips for Anastrozole (Arimidex)
- Take anastrozole (Arimidex) once a day with or without food. Try to take it at the same time each day to help you remember.
- If you miss a dose of anastrozole (Arimidex), take it as soon as you remember. If it’s almost time for your next dose, skip the missed one and take your regular dose. Don’t take two doses at once.
- Anastrozole (Arimidex) can weaken your bones, making them more prone to fractures. Your oncologist might recommend that you take calcium or vitamin D to strengthen your bones.
- Anastrozole (Arimidex) might raise cholesterol levels, which can raise your risk for serious heart disease. Your oncologist might order regular blood tests to make sure your cholesterol stays in a healthy range.
- 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.
- If you notice tingling, numbness, or a tickling feeling while taking anastrozole (Arimidex), contact your care team right away. These could be side effects that need attention.
- Avoid taking any medications that contain estrogen while taking anastrozole (Arimidex). Since this medication works to lower estrogen levels, adding more estrogen can make it not work as well.
- If you can become pregnant, use birth control while taking anastrozole (Arimidex) and for at least 3 weeks after your last dose. Contact your oncologist right away if you become pregnant or think you might be pregnant during treatment.
Common questions about Anastrozole (Arimidex)
You can take anastrozole (Arimidex) with or without food. But since this medication can cause hot flashes, you might want to limit spicy foods, caffeine, and alcohol, as these can make hot flashes worse. Talk to your oncologist if your symptoms become bothersome or don’t improve.
In studies, some people taking anastrozole (Arimidex) reported weight gain. But it's worth noting that weight gain is common during breast cancer treatment in general, not just with this medication. Talk to your oncologist if weight gain is a concern. They might suggest lifestyle changes like regular exercise and eating a balanced diet.
No. Anastrozole (Arimidex) isn't a chemotherapy drug. It's a type of hormone therapy that works by lowering estrogen levels in the body. Unlike chemotherapy, which kills all fast-growing cells (including cancer cells), anastrozole (Arimidex) slows or stops the growth of certain types of breast cancers that need estrogen to grow. It’s often used after chemotherapy or surgery to help prevent the cancer from coming back.
It can. In studies, some people who took anastrozole (Arimidex) experienced high blood pressure. If you notice symptoms like headaches, dizziness, or vision changes, talk to your oncologist. They can check your blood pressure and help manage it if needed.
Anastrozole (Arimidex) stays in your system for quite a while, around 8 to 10 days. It has a half-life of about 50 hours, which means it takes that long for your body to remove half of one dose. But this can vary slightly depending on your age, liver health, and other medical conditions.
During studies, a small percentage of people (2-5%) taking anastrozole (Arimidex) had hair loss or hair thinning. You might not see this right away since it can take several months to even years for changes to appear. If hair loss becomes a concern, discuss it with your oncologist.
Most people take anastrozole (Arimidex) for about 5 to 10 years. But taking it for many years can raise the risk of side effects, such as bone thinning, joint pain, or hot flashes. Whether you should continue beyond 10 years depends on your personal risk and how well you tolerate the medication. Always talk with your oncologist before making any changes to your treatment plan.
Yes. Anastrozole (Arimidex) can make you feel tired or fatigued. If your tiredness is severe or doesn’t get better, talk to your oncologist. They can check for other causes and suggest ways to help you feel better.
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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 blocked heart arteries
Anastrozole (Arimidex) can raise your risk of heart disease, especially if you've had blocked heart arteries in the past. Your oncologist will consider the risks and benefits before deciding if this medication is right for you. Get medical help right away if you start to have chest pain or feel out of breath while taking anastrozole (Arimidex).
Bone loss
Over time, anastrozole (Arimidex) can weaken your bones, which raises your risk for fractures, especially in your spine, hip, or wrist. This happens because the medication lowers estrogen levels, and estrogen plays an important role in keeping bones strong.
Your oncologist might recommend bone mineral density (BMD) testing before and during your treatment to make sure your bones stay healthy. These tests help monitor the strength and thickness of your bones. Your oncologist might also suggest you take calcium or vitamin D to help keep your bones strong during treatment.
Rise in cholesterol levels
Some people who take anastrozole (Arimidex) can develop a rise in cholesterol levels. Having too much cholesterol in your blood can clog your blood vessels and raise your risk of heart attack or stroke. Your oncologist might order regular blood tests to check your cholesterol while you’re taking this medication.
Harm to unborn baby
Anastrozole (Arimidex) can be harmful to an unborn baby. While most people taking this medication have already gone through menopause, some oncologists may prescribe it off-label for women who haven’t. If there’s any chance you could 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
Tablet| Dosage | Quantity | Price as low as | Price per unit |
|---|---|---|---|
| 1mg | 12 tablets | $10.07 | $0.84 |
Typical dosage 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.
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