Stop taking Arimidex and seek urgent medical treatment, if you experience any of the following serious but very rare side effects:

• An extremely severe skin reaction with ulcers or blisters on the skin. This is known as ‘Stevens-Johnson syndrome’.
• Allergic (hypersensitivity) reactions with swelling of the throat that may cause difficulty in swallowing or breathing. This is known as ‘angioedema’.

Very common side effects (affect more than 1 in 10 people)

• Headache.
• Hot flushes.
• Feeling sick (nausea).
• Skin rash.
• Pain or stiffness in your joints.
• Inflammation of the joints (arthritis).
• Feeling weak.
• Bone loss (osteoporosis).
• Depression.

Common side effects (affect 1 to 10 people in 100)

• Loss of appetite.
• Raised or high levels of fatty substance known as cholesterol in your blood. This would be seen in a blood test.
• Feeling sleepy.
• Carpal tunnel syndrome (tingling, pain, coldness, weakness in parts of the hand).
• Tickling, tingling or numbness of skin, loss/lack of taste.
• Diarrhoea.
• Being sick (vomiting).
• Changes in blood tests that show how well your liver is working.
• Thinning of your hair (hair loss).
• Allergic (hypersensitivity) reactions including face, lips, or tongue.
• Bone pain.
• Vaginal dryness.
• Bleeding from the vagina (usually in the first few weeks of treatment – if the bleeding continues, talk to your doctor).
• Muscle pain.

Uncommon side effects (affect 1 to 10 people in 1,000)

• Changes in special blood tests that show how your liver is working (gamma-GT and bilirubin).
• Inflammation of the liver (hepatitis).
• Hives or nettle rash.
• Trigger finger (a condition in which your finger or thumb catches in a bent position).
• Increased amounts of calcium in your blood. If you experience nausea, vomiting and thirst, you should tell your doctor, or pharmacist or nurse as you may need to have blood tests.

Rare side effects (affect 1 to 10 people in 10,000)

• Rare inflammation of your skin that may include red patches or blisters.
• Skin rash caused by hypersensitivity (this can be from allergic or anaphylactoid reaction).
• Inflammation of the small blood vessels causing red or purple colouring of the skin. Very rarely symptoms of joint, stomach, and kidney pain may occur; this is known as ‘Henoch-Schönlein purpura’.

Effects on your bones

Arimidex lowers the amount of the hormone called estrogen that is in your body. This may lower the mineral content of your bones. Your bones may be less strong and may be more likely to fracture. Your doctor will manage these risks according to treatment guidelines for managing bone health in women who have gone through the menopause. You should talk to your doctor about the risks and treatment options.

If any of the side effects get serious, or if you notice any side effects not listed in this leaflet, please tell your doctor or pharmacist.

Reporting of side effects

If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting side effects you can help provide more information on the safety of this medicine.