Arimidex (Anastrozole)
Complete patient guide for uses, dosage, side effects, and safety information
Prescription RequiredQuick Facts
What Is Arimidex Used For?
Arimidex contains anastrozole and is specifically designed to treat breast cancer in women who have gone through menopause. It works by reducing the amount of estrogen your body produces, which can help slow or stop the growth of certain types of breast cancer.
Primary Uses
Arimidex is used to treat breast cancer in women who no longer have menstrual periods – either naturally due to age, or after surgery, radiotherapy, or chemotherapy.
How It Works
Arimidex is a non-steroidal aromatase inhibitor that reduces the amount of estrogen (female sex hormone) made by the body. In some types of breast cancer, estrogen can help cancer cells grow. By blocking estrogen production, Arimidex may slow or stop cancer growth.
Good to know: Arimidex is not addictive.
How to Take Arimidex
Take Arimidex exactly as prescribed by your doctor. The medication should be taken consistently at the same time each day for best results.
Dosage Instructions
The usual dose is one tablet every day. Swallow Arimidex tablets whole with a glass of water. Take it at about the same time each day – this will help you remember and provide the best effect. It doesn’t matter if you take it before, with, or after food.
What If You Miss a Dose?
If you miss your dose at the usual time, take it as soon as you remember, as long as it is 12 hours before the next dose is due. If it’s less than 12 hours to your next dose, skip the missed dose and take your next dose when you’re meant to.
Important: Do not take a double dose to make up for the dose you missed.
Available Tablet Strengths
Side Effects
Like all medications, this medicine can cause side effects. Most are mild and temporary, but some require medical attention.
Common Side Effects
These side effects occur relatively frequently and usually don’t require emergency care:
- hot flushes
- feeling weak or lack of energy
- joint pain or stiffness
- bone loss (osteoporosis)
- mild skin rash
- feeling sick (nausea)
- headache
- feeling depressed
- feeling sleepy
- vaginal dryness
- vaginal bleeding
- thinning of hair (hair loss)
- diarrhea
- loss of appetite
- vomiting
- carpal tunnel syndrome
- pins and needles
- loss of taste or changing taste of food or drink
Seek immediate medical attention if you experience:
- sudden signs of allergy (shortness of breath, wheezing, difficulty breathing, swelling of face, lips, tongue or other body parts, rash, itching or hives)
- severe skin reactions with lesions, ulcers or blisters
- liver pain or swelling with or without jaundice (yellowing of skin and eyes)
Important Warnings
Before taking Arimidex, it’s crucial to discuss your medical history and current health status with your doctor to ensure this medication is safe for you.
Who Should Not Take Arimidex
Do not use Arimidex if you are allergic to anastrozole, other anti-estrogen medicines, or any ingredients in the medication. Do not take if you are still having menstrual periods or if you are a man. Arimidex should only be taken by women who are no longer having menstrual periods.
Medical Conditions to Discuss
Tell your doctor if you have liver problems, kidney problems, osteoporosis, a family history of osteoporosis, or risk factors for developing osteoporosis (such as smoking, a diet low in calcium, poor mobility, a slight build, or treatment with steroid medicines). Also inform your doctor about any allergies to medicines or other substances.
Pregnancy and Breastfeeding
Do not take Arimidex if you are pregnant or intend to become pregnant, as it may affect your developing baby. Do not breastfeed while taking Arimidex, as your baby can absorb the medication through breast milk.
Bone Health Warning: Aromatase inhibitors may decrease bone mineral density in postmenopausal women, with a possible increased risk of fractures. Your doctor should discuss treatment options for managing this risk.
Drug Interactions
Some medicines may interfere with Arimidex and affect how it works. Always tell your doctor about all medications you’re taking.
- tamoxifen (medicine used to treat breast cancer)
- any medicine containing estrogen (such as Hormone Replacement Therapy or oral contraceptives)
- health food products containing natural estrogens for post-menopausal symptoms
- LHRH agonists such as goserelin or leuprorelin
Alcohol & Driving
Be cautious when driving or operating machinery while taking Arimidex, as it may affect your ability to perform these activities safely.
Driving and Operating Machinery
Be careful before you drive or use any machines or tools until you know how Arimidex affects you. Some patients may occasionally feel weak or sleepy.
Storage
Keep your tablets in the blister pack until it’s time to take them – if you remove them from the blister pack, they will not keep well. Store in a cool, dry place where the temperature stays below 30°C. Keep away from moisture, heat, and sunlight. Do not store in the bathroom, near a sink, in the car on hot days, or on a window sill. Keep out of reach of children.
Overdose Information
If you think you have taken too much Arimidex, seek urgent medical attention immediately. Phone the Poisons Information Centre (13 11 26), contact your doctor, or go to the Emergency Department at your nearest hospital.
Frequently Asked Questions
No, Arimidex is not addictive.
Yes, it doesn’t matter if you take Arimidex before, with, or after food.
Take it as soon as you remember, as long as it’s 12 hours before your next dose. If it’s less than 12 hours to your next dose, skip the missed dose and take your next dose when scheduled. Never take a double dose.
Continue taking Arimidex for as long as your doctor tells you. It helps control your condition but doesn’t cure it, so you must take it every day. Don’t stop taking it unless your doctor tells you to, even if you feel better.
No, men are not normally treated with Arimidex. It should only be taken by women who are no longer having menstrual periods.
You should not take Arimidex if you are still having menstrual periods. This medication is only for women who no longer have menstrual periods.
Yes, aromatase inhibitors like Arimidex may decrease bone mineral density in postmenopausal women, with a possible increased risk of fractures. Your doctor should discuss treatment options for managing this risk with you.
Important Disclaimer
This information is intended for general educational purposes only and should not be considered medical advice. Always consult your healthcare provider or pharmacist before starting, stopping, or changing any medication.
If you think you may have a medical emergency, call your doctor or emergency services immediately.