Common questions about anastrozole - Brand name: Arimidex

Anastrozole belongs to a group of medicines called aromatase inhibitors.

Aromatase inhibitor medicines are used to treat or prevent certain types of breast cancer, where the cancer cells need oestrogen (a hormone) to grow.

After the menopause your ovaries stop producing oestrogen. Your body still makes small amounts of oestrogen using an enzyme called aromatase, which changes hormones called androgens into oestrogen.

Aromatase inhibitors reduce the amount of aromatase in your body and this stops your body producing oestrogen. This helps prevent cancer cells growing as they no longer have a source of oestrogen.

Anastrozole starts to reduce the amount of oestrogen in your body within 24 hours, but it takes several weeks or months for it to work fully.

During this time, you're likely to have menopause symptoms as your body gets used to having less oestrogen. These symptoms will gradually improve as your body gets used to the medicine.

Anastrozole is generally safe to take long term. However, your specialist team will monitor your health carefully.

This is because anastrozole reduces levels of oestrogen in your body. Your body needs oestrogen for strong and healthy bones. If you take anastrozole for a long time your bones can become weaker (osteoporosis) and may be more likely to break.

You will have bone density (DEXA) scans before you start taking anastrozole, 1 or 2 years into treatment and again after you finish your treatment.

Your doctor may recommend a type of medicine called a bisphosphonate to help reduce bone damage. They can also give you advice on exercise and diet to help keep your bones strong.

Anastrozole can also increase your cholesterol levels. Your doctor will monitor this during your regular check-ups and recommend treatment if you need it.

If you want to stop taking anastrozole for any reason, your doctor will be able to discuss alternatives for treating your breast cancer or preventing it coming back.

Sometimes people may have a short break from anastrozole. This can help if you're getting side effects such as joint pain. However, only take a break from your medicine if you've discussed it with your specialist first and they agree to it.

Medicines such as letrozole and exemestane work in a similar way to anastrozole. They are also aromatase inhibitors, and so they also lower your oestrogen level and can cause similar side effects.

However, medicines affect people in different ways. If you're bothered by side effects from taking anastrozole, talk to your doctor. They may recommend one of these other medicines instead.

Anastrozole helps stop your breast cancer coming back after having treatment for cancer.

The exact benefits and how well it's likely to work for you depend on a combination of different things.

This varies for each person and includes factors like your age when the breast cancer was found, how it was found and whether you've had chemotherapy or not.

Anastrozole can also be used to reduce the risk of breast cancer after the menopause if you have a medium or high risk of breast cancer because of your family history. Your specialist will discuss the likely benefits and risks of taking anastrozole to help prevent breast cancer.

Anastrozole is generally only given to you if you've gone through the menopause.

However, some people find that they start having periods again after taking anastrozole. If this happens to you, it's important to use reliable contraception.

Talk to your doctor if your periods start again, or if there's any chance that you could be pregnant.

Anastrozole is not recommended during pregnancy.

Some people feel extremely tired when taking anastrozole.

If you feel tired or dizzy, do not drive, cycle, or use tools or machinery until you feel OK again.

It's an offence to drive a car if your ability to drive safely is affected. It's your responsibility to decide if it's safe to drive. If you're in any doubt, do not drive.

Talk to your doctor or pharmacist if you're unsure whether it's safe for you to drive while taking anastrozole. GOV.UK has more information on the law on drugs and driving.

There's no evidence that drinking alcohol causes any problems when taking anastrozole.

Some people taking anastrozole may get hot flushes or redness when they drink alcohol. In this case, avoiding alcohol may help.

Most people can eat and drink normally when taking anastrozole.

Some people may get hot flushes or redness when they drink alcohol.

Some people find anastrozole affects their appetite.

If you lose your appetite, try to make sure you have a balanced diet. Try eating smaller meals more often instead of big meals.