Exemestano: What is it? How does it work? Administration, Side Effects and Interactions

It is a type of hormone therapy medication. Its trade name, Aromasin, also knows it.

It is a treatment for women with breast cancer who have had menopause.

How does it work?

Many breast cancers are stimulated to grow by the female sex hormones estrogen and progesterone. These breast cancers are called receptors sensitive to hormones or hormone receptors. Blocking the effects of these hormones can treat breast cancer.

In women who have had their menopause, estrogen occurs mainly by changing androgens (sex hormones produced by the adrenal glands) into estrogen. This process is called aromatization and occurs primarily in fatty tissues, muscles, and skin. You need a particular enzyme called aromatase.

Exemestane blocks the aromatization process. Therefore, it oppresses the set of estrogen in the body. In early breast cancer, taking exemestane can help stop the return of breast cancer. Cancer cells can grow more slowly in advanced breast cancer or stop growing altogether.


  • If you have exemestane in tablets, try to take it at the same time daily. Swallow the whole pill with a drink of water. It would help if you took it after eating.
  • It would help if you took tablets according to the instructions given by your doctor or pharmacist.
  • It would help if you took the correct dose, no more or less.
  • Never stop taking a cancer medication without first talking to your specialist.
  • Tell your doctor immediately if you accidentally take more exemestane than you should.
  • If you forget to take a tablet, take it as soon as you remember it. If it is almost time for the next dose, take that tablet at the usual time. Do not take a double amount to make up for the one you forgot.

Tests during treatment

Blood tests may be done before starting treatment and during your treatment. They control your general health and can manage your levels of blood cells and other substances in the blood.

Side effects

Tell your doctor or nurse if you have any side effects so they can help you manage them. Your nurse will give you a contact number to call if you have any questions or problems. If you have doubts, call them.


Common side effects

 Hot flashes and sweats

This effect occurs in more than 1 in 10 people (10%).

You can have hot flashes. You may also have other symptoms, such as:

  • Redness of the skin.
  • Perspiration.
  • An accelerated heart (palpitations).
  • I was feeling anxious, irritable, or panicky.

Tips to reduce hot flashes:

  1. Eliminate coffee, tea, and nicotine.
  2. Decrease alcohol consumption.
  3. Drink cold or frozen drinks.
  4. Wear layers of light clothing so you can remove your clothes if they get too hot.
  5. Have layers of bedding to remove when you need it.
  6. Use natural fibers such as silk or cotton instead of artificial fabrics.
  7. Talk to your doctor if your hot flashes are hard to cope with. It is possible that they can prescribe medication.

Other common symptoms are:

Joints or painful muscles

This occurs in more than 1 in 5 women (22%).

Tell your doctor or nurse if you have pain anywhere during or after receiving treatment. There are many ways to treat pain, including relaxation and pain killers.

Fatigue (fatigue)

You may feel tired during the treatment. You may also feel weak and lack energy.

Sometimes it can help you sleep for a short time during the day. Rest when you need it.

Several things can help you reduce fatigue and deal with it, for example, exercise. Some research has shown that light exercise can give you more energy. It is important to balance activity with rest.

This happens in about 1 in 6 women (16%).

Feeling sick

Feeling sick is usually mild. The tablets against the disease can control it if you need them. Tell your doctor or nurse if you feel unwell.

Difficulty sleeping ( insomnia )

Talk to your doctor or nurse if you have trouble sleeping. It can help to change some things about when and where you sleep.

Tips to reduce it:

  1. Go to bed and get up at the same time daily.
  2. Make sure the temperature is correct.
  3. Take time to relax before going to bed, take a bath, read or listen to music.
  4. Do a little light exercise every day to help you run out.
  5. Avoid caffeine (coffee, tea, chocolate, and cola drinks) after the afternoon.
  6. Take a light snack before bed to avoid being awakened by hunger.

More than 1 in 10 (10%) women present the following effects:


Tell your doctor or nurse if you have headaches. They can prescribe an analgesic like acetaminophen.


Tell your doctor or nurse if you suffer from belly pain. You could prescribe some medication or remedy to decrease it.


Tell your doctor or nurse if you feel depressed. They can arrange to talk to someone and give treatment if necessary, especially with a psychotherapist.


Do not drive any machine if you have this type of symptom.

Occasional side effects

Each of these effects occurs in more than 1 in 100 people (1%). You may have one or more of them.

 Loss of appetite

You may lose your appetite for several reasons when you have cancer treatment. Illness, changes in taste, or fatigue can discourage you from food and drinks.

Tips to control appetite:

  1. Eating several small meals and snacks can be easier to manage during the day.
  2. Ask your doctor or nurse to recommend high-calorie beverages between treatments if you are worried about losing weight.
  3. You can recover calories between treatments for the days when you do not feel like eating.
  4. Drink plenty of fluids, even if you can not eat.
  5. Do not fill your stomach with a large amount of liquid before swallowing.
  6. Try to eat high-calorie foods to maintain your weight.

Contact your doctor or pharmacist if you have indigestion or heartburn. They can prescribe medication to help you.


A rash can also cause itching. Tell your doctor or nurse if you have a rash. They can prescribe medications to stop the itching and soothe the skin.

 Loss of bone strength

The loss of bone strength is caused by a lack of estrogen over a long period. Bones are more likely to break. Before starting treatment, you may have a DEXA scan to check your bone density.

 Diarrhea or constipation

If you have diarrhea or constipation, it is usually mild. It would help if you drank lots of fluids.

 Vaginal bleeding

This medicine may cause vaginal bleeding. This occurs mainly in the first weeks of treatment. Tell your doctor or nurse if the bleeding continues.

Vaginal bleeding occurs in less than 1 in 20 women (5%).


Fluid buildup can cause inflammation of the ankle and fingers or a swollen face. It can also cause weight gain.

 Carpal tunnel syndrome

Carpal tunnel syndrome is when you have pain in your hands and a weak grip. You also feel numbness and tingling in your hands. Tell your doctor or nurse if you have this.

 Hair loss

Some hormonal therapies can cause hair loss or reduction of the thickness of the hair. In general, this is relatively mild and may not even be noticed.

This usually slows down or stops within the first year of beginning treatment.

Rare side effects

Each of these effects occurs in less than 1 in 100 people (1%). You may have one or more of them.


You may feel sleepy with this treatment. Do not operate machinery or drive if you feel tired.

 Inflammation of your liver

Liver inflammation (hepatitis) can be detected in blood tests before the symptoms appear. Symptoms include:

  1. A high temperature (fever).
  2. Pain in the joints and muscles.
  3. Feeling more tired than usual
  4. Pain in the belly (abdomen).
  5. Dark urine.
  6. Yellowing of the skin and eyes ( jaundice ).

Tell your doctor if you have any of the above symptoms or if you have new, persistent, or worsening symptoms.

 Yellowing of the skin

This is called jaundice. It is caused by high levels of bile pigments in the blood. Tell your doctor or nurse immediately.


Other medicines, food, and beverages

Cancer drugs can interact with some other medicines and herbal products. Tell your doctor or pharmacist about any medication you are taking. This includes vitamins, herbal supplements, and over-the-counter remedies.

Do not take hormone replacement therapy while receiving treatment with exemestane.

Treatment for other conditions

Always inform other doctors, nurses, pharmacists, or dentists that you are receiving this treatment if you need treatment for anything else, including dental problems.

Sugar intolerance

Exemestane contains a small amount of sucrose (a type of sugar). Tell your doctor if you have an intolerance to any kind of sugar.