Anastrozole is used to treat early hormone receptor-positive breast cancer. It is also used for first-line treatment of hormone receptor-positive or hormone receptor-unknown advanced or metastatic (cancer that has spread) breast cancer. Anastrozole is also used to treat advanced breast cancer that has grown or spread after tamoxifen treatment. This medicine is used only in women who have already stopped menstruating (postmenopausal).

Anastrozole Course For Woman

Many breast cancer tumors grow in response to estrogen. This medicine interferes with the production of estrogen in the body. As a result, the amount of estrogen that the tumor is exposed to is reduced, limiting the growth of the tumor.

This medicine is available only with your doctor’s prescription.

Anastrozole lowers estrogen levels in postmenopausal women, which may slow the growth of certain types of breast tumors that need estrogen to grow in the body.

Anastrozole is used to treat breast cancer in postmenopausal women. It is often given to women whose cancer has progressed even after taking tamoxifen (Nolvadex, Soltamox).

Anastrozole may also be used for purposes not listed in this medication guide.


Anastrozole may decrease blood flow to your heart, especially if you have ever had coronary artery disease (clogged arteries). Seek medical attention if you have new or worsening chest pain, or if you feel short of breath.

Before taking this medicine

You should not use anastrozole if you are allergic to it, or if you have not yet completed menopause.

Anastrozole is not approved for use in men or children.

You should not take anastrozole if you also take tamoxifen.

Tell your doctor if you have ever had:

  • heart problems;
  • coronary artery disease (clogged artery disease);
  • high cholesterol; or
  • osteoporosis or low bone mineral density.

Hormonal cancer treatment can weaken your bones. You may be more likely to have a broken bone while using anastrozole. Talk with your doctor about ways to keep your bones healthy.

Although it is not likely that a postmenopausal woman would be pregnant, anastrozole may harm an unborn baby. You may need to have a negative pregnancy test before starting this treatment. Use effective birth control if you are not past menopause. Keep using birth control for at least 3 weeks after your last dose of anastrozole. Tell your doctor if you become pregnant.

Do not breastfeed while using anastrozole, and for at least 2 weeks after your last dose.

How should I take anastrozole?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Anastrozole is usually taken once per day. Follow your doctor’s dosing instructions very carefully.

You may take anastrozole with or without food.

You may need to keep taking this medication for up to 5 years. Follow your doctor’s instructions.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

What happens if I miss a dose

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What should I avoid while taking anastrozole?

Avoid driving or hazardous activity until you know how anastrozole will affect you. Your reactions could be impaired.

Anastrozole side effects

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Anastrozole may decrease blood flow to your heart, especially if you have ever had coronary artery disease (clogged arteries). Seek medical attention if you have new or worsening chest pain, or if you feel short of breath.

Call your doctor at once if you have:

  • shortness of breath (even with mild exertion), swelling, rapid weight gain;
  • numbness, prickly feeling, pain, or weakness in your hands or wrists;
  • symptoms of bone fracture–bruising, swelling, tenderness, pain that worsens with movement;
  • liver problems–right-sided upper stomach pain, yellowing of your skin or eyes, and not feeling well; or
  • signs of a stroke–sudden numbness or weakness (especially on one side of the body), sudden severe headache, slurred speech, problems with vision or balance.

Common side effects may include:

  • numbness, tingling, or tickling feeling in your skin;
  • hot flashes;
  • weakness;
  • joint pain or stiffness;
  • bone pain, risk of fracture;
  • swelling in your arms, legs, or feet;
  • sore throat, cough, shortness of breath;
  • headache, back pain;
  • depression, sleep problems (insomnia);
  • high blood pressure;
  • nausea, vomiting; or
  • rash.

Usual Adult Dose for Breast Cancer:

Initial dose: 1 mg orally taken once a day
Duration of therapy: Until tumor progression (treatment of advanced breast cancer); unknown (adjuvant treatment of early breast cancer)

-Adjuvant treatment of postmenopausal women with hormone receptor-positive early breast cancer;
-First-line treatment of postmenopausal women with hormone receptor-positive or hormone receptor unknown locally advanced or metastatic breast cancer;
-Second-line treatment of advanced breast cancer in postmenopausal women with disease progression following tamoxifen therapy.

How to cope with the side effects of anastrozole

How to cope

Menopause symptoms such as hot flushes, difficulty sleeping, tiredness and low mood usually improve during the first months of taking anastrozole. However, if they are severe or last longer than a few months, talk to your doctor or breast cancer nurse.

What to do about:

  • hot flushes and sweating – try cutting down on spicy food, caffeine, smoking and alcohol. It may help to keep the room cool and use a fan. Try spraying your face with cool water, or sipping a cold drink.
  • dry or itchy vagina, bleeding from your vagina – ask your doctor or breast cancer nurse to recommend a vaginal moisturiser for treating irritation or dryness. Vaginal bleeding usually happens in the first few weeks after starting anastrozole. Talk to your doctor if it lasts longer than a few days. Also talk to your doctor if these symptoms first appear more than a few weeks after you start taking anastrozole.
  • difficulty sleeping – avoid caffeine (tea, coffee, cola and chocolate) in the afternoon and evening. Keep your bedroom dark and quiet, and try going to bed and getting up at a set time each day. It may also help to stop watching TV, looking at your mobile phone or using other electronic devices (like tablets), at least 1 hour before bedtime.
  • feeling very tired – gentle exercise and eating healthily can help make you feel less tired. Try going to bed and getting up at a set time each day. Do not drive, ride a bike or operate machinery if you feel very tired while taking anastrozole. This will usually start to improve as your body gets used to the medicine. Speak to your doctor if it does not get better.
  • feeling or being sick, loss of appetite – it might help to take anastrozole after you’ve eaten. Choose foods you normally enjoy but avoid rich or spicy food. Try eating smaller meals but more often. If you’re being sick, have small, frequent sips of water to avoid dehydration. Talk to your doctor if your symptoms do not improve or get worse.
  • mild aches in your muscles or bones – ask a pharmacist to recommend a suitable painkiller. If the pain lasts more than a week, ask your doctor for advice. If you have a sudden attack of pain in a joint ask a doctor for advice urgently.
  • numb or tingling hands – stop taking the medicine and ask your doctor for advice
  • changes to your skin, including a mild rash – it may help to take an antihistamine. You can buy these at a pharmacy without a prescription. Check with a pharmacist to see what’s suitable for you.
  • hair loss or thinning hair – some people find that their hair gets thinner when they start taking anastrozole. This is usually mild. Ask your breast cancer nurse for advice if this is bothering you.
  • low mood or depression – it is difficult to know whether this is due to the medicine or a response to menopausal symptoms or being diagnosed with cancer. Speak to your doctor or specialist nurse. They may recommend therapies, like cognitive therapy and mindfulness, or antidepressant medicines.

Pregnancy and breastfeeding

Anastrozole is not recommended when pregnant or breastfeeding, because it interferes with hormone levels in you and your baby. And there is not enough information available to say if it’s safe.

Talk to your doctor straight away if there is any chance that you could be pregnant.