Anastrozole is used to treat breast cancer in women after menopause. Some breast cancers are made to grow faster by a natural hormone called estrogen. Anastrozole decreases the amount of estrogen the body makes and helps to slow or reverse the growth of these breast cancers.
How to use Anastrozole
Read the Patient Information Leaflet if available from your pharmacist before you start taking anastrozole and each time you get a refill. If you have any questions, ask your doctor or pharmacist.
Take this medication by mouth with or without food as directed by your doctor, usually once a day.
What Anastrozole Is Used For:
- Anastrozole is used to treat breast cancer in postmenopausal women.
Note: If a drug has been approved for one use, physicians sometimes elect to use this same drug for other problems if they believe it might be helpful.
How Anastrozole Is Given:
- Anastrozole is a pill, taken by mouth.
- You should take anastrozole at about the same time each day.
- You may take anastrozole with or without food.
- If you miss a dose of anastrozole, take it as soon as you remember unless it is almost time for the next dose. Do not take a double dose to make up a missed dose.
- You should not stop taking anastozole without discussing with your physician, even if you feel well.
The amount of anastrozole that you will receive depends on many factors, including your general health or other health problems, and the type of cancer or condition being treated. Your doctor will determine your dose and how long you will be taking anastrozole.
Important things to remember about the side effects of anastrozole:
- Most people do not experience all of the anastrozole side effects listed.
- Anastrozole side effects are often predictable in terms of their onset, duration, and severity.
- Anastrozole side effects will improve after therapy is complete.
- Anastrozole side effects may be quite manageable: There are many options to help minimize or prevent the side effects of anastrozole.
The following side effects are common (occurring in greater than 30%) for patients taking Anastrozole:
- Hot Flashes
- Muscle/Joint pain
- Stomach upset
The following side effects are less common (occurring in 10-29%) for patients taking anastrozole:
- Decreased energy
- Mood disturbances
- Sore throat
- High blood pressure
- Osteoporosis (Weak bones)
- Back pain
- Insomnia (Trouble sleeping)
- Peripheral edema and lymphedema (fluid build-up)
- Dyspnea (difficulty breathing)
- Increased cough
Not all side effects are listed above, some that are rare (occurring in less than 10% of patients) are not listed here. However, you should always inform your health care provider if you experience any unusual symptoms.
Contact your health care provider immediately, day or night and go to the nearest emergency room, if you should experience any of the following symptoms:
- New or worsening chest pain
- Shortness of breath
- Swelling of the face, lips, tongue and/or throat
- Difficulty swallowing and/or breathing.
The following symptoms require medical attention, but are not emergency situations. Contact your health care provider within 24 hours of noticing any of the following:
- Vaginal bleeding (similar to a period)
- Tickling, Tingling, or Numbness of your skin
- Nausea (interfering with ability to eat and unrelieved with prescribed medication)
- Vomiting (vomiting more than 4-5 times in a 24 hour period)
- Yellowing of your skin or the whites of your eyes
- Pain on the right side of your stomach-area
Always inform your health care provider if you experience any unusual symptoms.
- Before starting anastrozole treatment, make sure you tell your doctor about any other medications you are taking (including over-the-counter drugs, vitamins, or herbal remedies)
- Anastrozole interacts with certain medications. Make sure you tell your doctor if you are taking these medications:
- Estrogen/estradiol-containing medications (commonly used for menopause and birth-control)
- Before starting anastrozole treatment, make sure you tell your doctor about health conditions you have including: heart conditions, osteoporosis, and abnormal cholesterol. Anastrozole may cause increased risk for heart disease. Talk with your healthcare provider to weigh the benefit and risks.
- Inform your health care professional if you have not had menopause yet (premenopausal).
- Inform your health care professional if you are pregnant or may be pregnant prior to starting this treatment. Anastrozole is pregnancy category X (anastrozole may be hazardous to the fetus. Anastrozole is contraindicted in women who are pregnant or may become pregnant).
- Anastrozole may enter breast milk. It is unclear what effect this may have on babies. Tell your doctor if you are breastfeeding or plan to breastfeed.