Arimidex (generic: anastrozole) 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 is a prescription medicine used:
- in the treatment of early breast cancer:
- after surgery
- in women whose breast cancer is hormone receptor-positive
- for the first treatment of breast cancer that has spread to nearby tissue or lymph nodes (locally advanced) or has spread to other parts of the body (metastatic), in women whose breast cancer is hormone receptor-positive or the hormone receptors are not known
- for treatment of advanced breast cancer, if the cancer has grown, or the disease has spread after tamoxifen therapy
This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.
Arimidex may cause serious side effects. See "Drug Precautions" section.
Common side effects in women taking Arimidex include:
- hot flashes
- joint pain
- carpal tunnel syndrome (tingling, pain, coldness, weakness in parts of the hand)
- sore throat
- mood changes
- high blood pressure
- nausea and vomiting
- thinning of the hair (hair loss)
- back pain
- sleep problems
- bone pain
- 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.
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 are taking:
- 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 may cause serious side effects including:
- Heart disease. Women with early breast cancer, who have a history of blockages in heart arteries (ischemic heart disease) and who take Arimidex may have a slight increase in this type of heart disease compared to similar patients who take tamoxifen. Stop taking Arimidex and call your doctor right away if you have chest pain or shortness of breath. These can be symptoms of heart disease.
- Osteoporosis (bone softening and weakening). Arimidex lowers estrogen in your body, which may cause your bones to become softer and weaker. This can increase your chance of fractures, specifically of the spine, hip and wrist. Your doctor may order a test for you called a bone mineral density study before you start taking Arimidex and during treatment with Arimidex as needed.
- increased blood cholesterol (fat in the blood). Your doctor may do blood tests to check your cholesterol while you are taking Arimidex.
- skin reactions. Stop taking Arimidex and call your doctor right away if you get any skin lesions, ulcers, or blisters.
- severe allergic reactions. Get medical help right away if you get:
- swelling of your face, lips, tongue, or throat
- trouble swallowing or breathing
- liver problems. Arimidex can cause inflammation of your liver and changes in liver function blood tests. Your doctor may check you for this.Stop taking Arimidex and call your doctor right away if you have any of these signs or symptoms of a liver problem:
- a general feeling of not being well
- yellowing of your skin or whites of your eyes
- pain on the right side of your stomach-area (abdomen)
Do not take Arimidex if you:
- are pregnant, think you may be pregnant, or plan to get pregnant
- have not finished menopause (are premenopausal)
- are allergic to any of the ingredients in Arimidex
- are a man or child.
- are taking tamoxifen or estrogen-containing medicines
Medicines can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of Arimidex there are no specific foods that you must exclude from your diet when receiving Arimidex.
Before taking Arimidex, tell your doctor about all your medical conditions, including if you:
- have not finished menopause.
- have or had a heart problem
- have a condition called osteoporosis
- have high cholesterol
- are pregnant or breastfeeding.
Tell your doctor about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements.
Tell your doctor if you are pregnant or are planning to become pregnant. Arimidex may harm your unborn child.
Tell your doctor if you are breastfeeding or are planning to breastfeed. It is not known if Arimidex is excreted in breast milk or if it will harm your baby.
Take Arimidex exactly as prescribed by your doctor. Keep taking Arimidex for as along as your doctor prescribes it for you.
Arimidex comes as a tablet to be taken by mouth with or without food. It is usually taken once a day. If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose. Take your next regularly scheduled dose. Do not take two doses at the same time.
Arimidex is usually taken once daily with or without food. Take Arimidex exactly as prescribed by your doctor.
The dose of Arimidex is one 1 mg tablet taken once a day. For patients with advanced breast cancer, Arimidex should be continued until tumor progression. Arimidex can be taken with or without food. For adjuvant treatment of early breast cancer in postmenopausal women, the optimal duration of therapy is unknown. In the ATAC trial, Arimidex was administered for five years. No dosage adjustment is necessary for patients with renal impairment or for elderly patients.
If you have taken too much Arimidex seek emergency medical help or contact your local Poison Control Center right away.
Arimidex is available in 1 mg tablets.
Active ingredient: anastrozole
Inactive ingredients: lactose, magnesium stearate, hydroxypropylmethylcellulose, polyethylene glycol, povidone, sodium starch glycolate, and titanium dioxide.
- Store Arimidex at 68°F to 77°F (20°C to 25°C).
- Keep Arimidex and all medicines out of the reach of children.
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