Letrozole

Uses

Precaution

Side Effects

Handling

Uses

What is Letrozole for?

Letrozole is used to treat breast cancer that is hormone-sensitive. It may be used alone or in combination with other medications.
It works by reducing the amount of estrogen (a hormone) in your body, to slow down or stop the growth of breast cancer cells that need estrogen to grow.

How should I take or use Letrozole?

Take Letrozole once a day, with or without food.
Swallow the tablet/capsule whole.
- Do not break, chew or crush the tablet.
- Inform your doctor or pharmacist if you have difficulty swallowing.

What should I do if I forget to take or use Letrozole?

If you forget to take a dose, take it as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and take it at the next scheduled time. Do not take two doses to make up for the missed dose.
If you vomit out a dose of Letrozole, do not take another dose to make up for it. Take your next dose at the usual time.

Precaution

What precautions should I take when taking or using Letrozole?

Inform your healthcare professional if:
- You are allergic to this medication or any of the other ingredients of this medication.
- You are taking any other medications, including supplements, traditional medications and herbal remedies.
- You have any other medical conditions such as heart, liver or kidney conditions.
You should not breastfeed during treatment and for at least 3 weeks after stopping Letrozole.
You should not become pregnant during treatment. You should use an effective birth control method during treatment and for at least 3 weeks after stopping Letrozole.

What food or medication should I avoid when I take or use Letrozole?

Avoid taking letrozole with tamoxifen, other anti-estrogen medications, or any medications containing estrogen (such as hormone replacement therapy), as these may make Letrozole less effective.

Side Effects

What are some common side effects of Letrozole?

The table below will list some of the common side effects as well as the rare but serious side effects.

Side Effect	Management
Hot flushes (sudden sweating and feeling of warmth)	Wearing light clothing and staying in a cool environment may reduce these symptoms. Inform your doctor if these symptoms affect you significantly.
Vaginal itching, dryness, discomfort, (bleeding) or vaginal discharge	Inform your doctor early if these symptoms affect you significantly. Use a water-based vaginal lubricant to help relieve vaginal dryness. You may experience vaginal bleeding in the first few weeks after starting Letrozole. If the bleeding continues, inform your doctor.
Muscle aches and/or joint pain	Light exercises e.g. stretching can help with joint stiffness and aches. Mild pain can be relieved by taking Paracetamol. Inform your doctor if the pain is not better. Taking regular warm baths may help.
Feeling tired or lack of energy	Do not drive or operate machinery if you are feeling tired. Eat well and get enough sleep. Prioritize tasks to ensure you make the best use of your energy. Simple exercise such as walking can help to boost your energy. Avoid alcohol as this may cause you to feel more tired and drowsy.
Increase in cholesterol or triglycerides levels	You may have your cholesterol level checked before starting Letrozole, and periodically after starting Letrozole. Your doctor may prescribe medications to control your cholesterol levels if required.
Bone loss or thinning, which may lead to an increased risk of bone fractures	Consume food that is rich in Calcium and Vitamin D as these are needed to build strong bones. Your doctor may also prescribe Calcium and Vitamin D supplements for you. Your doctor will monitor your bone density and prescribe medications to strengthen your bones when required Try to do weight-bearing exercises like walking or climbing stairs for 30 minutes, at least 3 times a week. This will help to strengthen your bones.
Symptoms of drug allergy including one or more of the following: Swollen face/eyes/lips/tongue Difficulty in breathing Itchy skin rashes over your whole body	If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately.

It is normal to experience some side effects from Letrozole. As discussed with your doctor, taking Letrozole will be beneficial for your condition. Do not stop taking Letrozole without checking with your doctor.

Handling

How should I store Letrozole?

Store in a cool and dry place, away from direct sunlight. Keep this medication away from children.

How do I throw away Letrozole safely?

Pack this medication into a black trash bag and seal it tightly before throwing into the rubbish chute or bin.

Disclaimers

Please take note that the above is not a complete list of all possible side-effects. If you have any concerns about your medication or if you have other side-effects that you think are caused by this medication, please consult your doctor or pharmacist. If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (NHG Health, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.