Toremifene (Fareston®)

Hormones are chemicals that our bodies make. Hormones act as messengers and help control how cells and organs work. Hormonal therapies are drugs that change the way hormones are made or how they work in the body.

Many breast cancers rely on the hormone oestrogen (or estrogen) to grow. This is called oestrogen-receptor positive (ER positive) breast cancer. Toremifene blocks oestrogen from reaching the cancer cells. This means the cancer may grow more slowly. Or it may stop growing altogether.

Toremifene comes as tablets you can take at home. You may have toremifene on its own, or with other drugs. Your nurse or doctor will talk to you about your treatment plan. 

You usually take toremifene once a day. You can take it with or without food.

Always take the tablets exactly as explained. This is important to make sure they work as well as possible for you. 

If you forget to take a tablet, take the next tablet as usual. Do not take a double dose. If you have missed more than 1 dose, tell your doctor or nurse.

Other things to remember about your tablets:

• Keep them in the original package and at room temperature, away from heat and direct sunlight.
• Keep them safe and out of sight and reach of children.
• If you are sick just after taking the tablets, contact your healthcare team. Do not take another dose.
• Get a new prescription before you run out of tablets, and make sure you have plenty for holidays.
• If your treatment is stopped, return any unused tablets to the pharmacist. 

Your nurse or pharmacist may also give you other medicines to take home. Take all your medicines exactly as they have been explained to you. Do not stop taking any of your medicines unless your doctor tells you to. 

Hot flushes are a common side effect of this treatment. During a flush, your neck and face may feel warm. If you have white skin, your skin may look red. If you have black or brown skin, your skin colour may deepen. Flushes can last up to 5 minutes. You might also have sweats or feel anxious or irritable during a flush. 

Here are some things you can do to reduce the effects of hot flushes:

• Wear natural fabrics, such as cotton.
• Wear layers so you can remove clothes as needed. 
• Use cotton sheets and layers of bedding you can remove. 
• Try cooling pads or pillows to keep you cool.
• Keep rooms cool or use a fan.
• Have cold drinks and avoid caffeine and alcohol. 

You might have fewer hot flushes as your body adjusts to this treatment. You could try therapies to help you cope with hot flushes, such as:

• talking therapies like cognitive behaviour therapy (CBT)
• controlled breathing exercises
• yoga
• acupuncture. 

If they do not improve, talk to your doctor. Certain drugs can help to improve hot flushes. 

Flushes usually stop a few months after treatment ends. But some people continue to have them.

You may have a white or yellowish vaginal discharge when taking this treatment. Or you may bleed from the vagina. If bleeding continues for more than a few days, tell your doctor or nurse.

You may put on weight or your ankles and legs may swell because of fluid building up. Tell your doctor or nurse if you notice this. If your ankles and legs swell, it can help to put your legs up on a foot stool or cushion.

Feeling tired is a common side effect. Try to pace yourself and plan your day so you have time to rest between activities.

Being physically active can help to manage tiredness and give you more energy. It also:

• helps you sleep better
• reduces stress
• improves your bone health.

If you feel sleepy, do not drive or operate machinery.

This treatment can affect your skin. It may cause a rash, which may be itchy. Your doctor or nurse can tell you what to expect. If your skin feels dry, try using soap-free cleansers and unperfumed moisturising cream every day. 

Always tell your doctor or nurse about any skin changes. They can give you advice and may prescribe creams or medicines to help. Changes to your skin usually improve when treatment ends.

This treatment may make you feel dizzy. Rarely, it causes blurred vision or changes in eyesight. Always tell your doctor or nurse if you have any of these side effects. If you feel dizzy or have changes in your sight, do not drive or operate machinery.

You may feel low or depressed, or have mood swings, during this treatment. Talking to family and friends about how you feel might help. If mood changes last for more than a few weeks, tell your doctor, nurse or pharmacist. They can talk to you about different ways to manage low mood or depression.

Some medicines can affect how this treatment works or be harmful while you are having it. Always tell your cancer doctor, nurse or pharmacist about any drugs you are taking or planning to take, such as: 

• medicines you have been prescribed
• medicines you buy in a shop, pharmacy or online
• vitamins or supplements 
• herbal drugs and complementary or homeopathic therapies
• recreational drugs – for example, cannabis.

Toremifene tablets contain a type of sugar called lactose. If you have been told by a doctor that you cannot digest some sugars or are lactose intolerant, talk to your doctor before taking this drug.

If you need medical treatment for any reason other than cancer, always tell the healthcare professional that you are having cancer treatment. Give them the contact details for your cancer doctor or cancer team so they can ask for advice.

If you have appointments with a dentist, always tell them you are having cancer treatment. Talk to your cancer team before you have any dental treatment.