Experiences with
LetrozoleLetrozole is a medicine used to treat breast cancer and help to prevent breast cancer coming back.
It's mainly prescribed for women who have been through the menopause and have a type of cancer called hormone-dependent breast cancer.
Most people who take letrozole will have had primary treatment such as surgery, radiotherapy or sometimes chemotherapy to treat their breast cancer first. Letrozole is an additional (adjuvant) treatment which helps stop the cancer coming back.
Letrozole is sometimes given alongside another breast cancer medicine, called tamoxifen.
Letrozole is available on prescription only and comes as tablets.
It can also be used:
- to prevent breast cancer if you're high risk and have been through the menopause
- to treat cancer if you cannot have surgery, or to shrink the cancer before surgery if you cannot have chemotherapy
It can sometimes be used to treat breast cancer in men, or in women who have not reached the menopause.
Letrozole can occasionally be used as a fertility treatment if you have polycystic ovary syndrome (PCOS). If you're taking it as a fertility treatment and you need more information, speak to your specialist.
Who can take letrozole
Most adults aged 18 years old and over can take letrozole.
Who may not be able to take letrozole
Letrozole is not suitable for some people. Tell your doctor before starting to take this medicine if you:
- have ever had an allergic reaction to letrozole or any other medicine
- still have periods
- are pregnant or breastfeeding
- are trying to get pregnant – unless you are taking it as a fertility treatment
- have serious kidney or liver disease
- have been told you have fragile or brittle bones (osteoporosis)
Dosage
Letrozole comes as 2.5mg tablets. The usual dose is 1 tablet taken once a day.
How to take it
Try to take your letrozole at the same time each day. You can choose a time that suits your routine. This will make it easier to remember to take your medicine.
Swallow the tablet whole with a drink of water. Do not crush or chew it.
You can take letrozole with or without food.
How long to take it for
You'll usually take letrozole for about 5 years but it can sometimes be up to 10 years.
You may be prescribed letrozole on its own or letrozole and another breast cancer medicine called tamoxifen.
If you're taking both letrozole and tamoxifen, you'll usually take them together for the first few years and then letrozole on its own for the remaining time. Your specialist will tell you how long to take it for.
If you forget to take it
If you forget a dose of letrozole, take it as soon as you remember, unless your next dose is due in less than 3 hours. In this case, skip the missed dose and take your next dose at the usual time.
Never take 2 doses at the same time. Do not take an extra dose to make up for a forgotten one.
If you forget doses often, it may help to set an alarm to remind you. You could also ask your pharmacist for advice about other ways to help you remember to take your medicine.
If you take too much
If you take too many letrozole tablets, you may feel sick, get blurred vision or a fast heartbeat.
- you take more than your prescribed dose of letrozole and feel unwell
Get help from 111 online or call 111
If you need to go to A&E, do not drive. Ask someone to drive you or call 999 and ask for an ambulance.
Bring the letrozole packet or leaflet inside it, any remaining medicine, and any other medicines you take.
If you want to stop taking letrozole for any reason, your doctor will be able to discuss alternatives for treating your breast cancer or preventing it coming back.
Sometimes people are given a short break from letrozole. 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.
Do not stop taking letrozole without talking to your doctor first.
Common side effects
Letrozole can cause symptoms similar to the menopause such as hot flushes, difficulty sleeping, tiredness and low mood, but these usually improve during the first months of taking it. However, if the symptoms are severe or last longer than a few months, talk to your doctor or breast cancer nurse.
These common side effects of letrozole happen in more than 1 in 100 people. There are things you can do to help cope with them:
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.
Vaginal bleeding usually happens in the first few weeks after starting letrozole. Talk to your doctor if it lasts longer than a few days.
Also talk to your doctor if vaginal bleeding first appears more than a few weeks after you start taking letrozole.
Gentle exercise and eating a healthy diet 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 letrozole.
Speak to your doctor if this problem does not gradually improve as your body gets used to the medicine.
Stick to simple meals and do not eat rich or spicy food. It might help to take letrozole after you've eaten.
If you're being sick, try small frequent sips of water to avoid dehydration. Signs of dehydration include peeing less than usual or having dark strong-smelling pee.
If you take the combined pill or progestogen-only pill and you're being sick your contraception may not protect you from pregnancy. Check the pill packet for advice.
Talk to your doctor if your symptoms do not improve or get worse.
It might help to take letrozole after you've eaten.
Eat when you would usually expect to be hungry. If it helps, eat smaller meals more often than usual. Snack when you're hungry. Have nutritious snacks that are high in calories and protein, such as dried fruit and nuts.
Ask a pharmacist to recommend a suitable painkiller. If the pain does not go away ask your doctor for advice.
If you have a sudden attack of pain in a joint ask a doctor for advice urgently. Letrozole can make your bones weaker and there is an increased risk of osteoporosis or bone injuries.
Some people find their hair gets thinner when they start taking letrozole. This is usually mild. Ask your breast cancer nurse for advice if this is bothering you.
It's difficult to know whether this is due to the medicine, dealing with menopausal symptoms or dealing with a diagnosis of cancer.
Speak to your doctor or specialist nurse. They may recommend therapies, like cognitive behavioural therapy or mindfulness, or antidepressant medicines.
Talk to your doctor or a pharmacist if this advice on how to cope does not help and these side effects bother you or do not go away.
Serious side effects
Serious side effects are rare and happen in less than 1 in 100 people.
Call a doctor or call 111 now if you have:
- throbbing or cramping pain, swelling, warmth and redness (this may be harder to see on brown or black skin) in a leg or arm – these can be signs of a blood clot
- muscle weakness, pain or swelling in the joints or tendons in your ankle, calf or legs, shoulders or arms
- a high temperature or chills – these can be signs of an infection
- frequent mouth ulcers or frequent sore throat – these can be signs of a low white blood cell count
- yellow skin (this may be less obvious on brown or black skin) or the whites of your eyes turn yellow – this can be a sign of liver problems
- problems when you pee, including peeing more often or urgent need to pee – these can be signs of a urinary tract infection (UTI)
- blurred vision
- you have sudden weakness or if you lose feeling in any part of your body, if your face drops on 1 side or you have difficulty speaking – these can be signs of a stroke
- you have very sudden chest pain – this can be a sign of a heart attack
In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to letrozole.
Meds New IA (H4) - serious allergic reactionLetrozole is generally safe to take for a long time. However, it can make your bones weaker and more likely to break (osteoporosis).
You may have bone density (DEXA) scans to check how strong your bones are, before you start taking letrozole, 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 make your bones stronger. They can also give you advice on exercise and diet to help keep your bones strong.
Letrozole can also increase your blood pressure and cholesterol levels. Your doctor will monitor these during your regular check-ups and recommend treatment if you need it.
Other side effects
These are not all the side effects of letrozole. For a full list, see the leaflet inside your medicines packet.
Letrozole and pregnancy
Letrozole is not recommended when pregnant. This is because it affects your hormones and this can affect how your baby develops.
Talk to your doctor urgently if there is any chance that you could be pregnant.
Letrozole and breastfeeding
Letrozole is not recommended while you're breastfeeding.
There's no information on how letrozole passes into breast milk but it's likely to be a fairly high amount compared to most other medicines.
Letrozole affects hormones, which may affect how your baby develops.
Letrozole and fertility
Letrozole is sometimes used as a fertility treatment. Your fertility specialist will be able to answer any questions that you may have when it is being used for this purpose.
Meds New IA (H2) - Pregnancy non-urgent care cardCautions with other medicines
Letrozole should not be taken with medicines for menopause symptoms, like hormone replacement therapy (HRT). These may contain ingredients similar to the hormone oestrogen. This could stop letrozole working as well as it should in treating your cancer.
It is OK to take letrozole with most other medicines.
Mixing letrozole with herbal remedies and supplements
Do not take any herbal remedies or supplements for menopause symptoms while taking letrozole. These can stop letrozole working as well as it should.
There's not enough information to say that other complementary medicines, herbal remedies and supplements are safe to take with letrozole. They're not tested in the same way as pharmacy and prescription medicines. They're generally not tested for the effect they have on other medicines.
Meds New IA (H2) - Cautions with other medicines alertRelated links
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