Femozol - Precautions | Dosage | Side Effects

This article was medically reviewed by M.Pharm, Marko Tanaskovic on August 12, 2018. To read more about an author, click here.

Femozol, namely its active substance - letrozole, is the anticancer drug from the group of the aromatase inhibitors. Blocking the enzyme aromatase prevents the production of estrogen, and this effect is used in the treatment of estrogen-dependent breast cancer. Estrogen accelerates the growth of breast tumors and in these patients, drugs that lower the level of estrogen in the blood (such as Femozol) should be used. In this way, Femozol blocks the growth of breast tumors. Since the enzyme aromatase is functional only in postmenopausal women, Femozol is effective only in women who have gone through menopause.

It may also be used in the prevention of relapse of breast cancer.

It can be used as first-line therapy, even before surgical intervention (if it is not feasible at the time) and can also be used after surgical removal of the tumor.

When Femozol should not be applied?

Femozol cannot be used in women who have not gone through menopause and still have menstrual cycles.

It should not be used in women who are pregnant or breastfeeding. Also, it should not be used in patients younger than 18 years.

What special precautions to take while taking Femozol?

Femozol must be used very cautiously in the following conditions:

  • Damage / weakness of the liver
  • Damage / weakness of the kidney
  • Osteoporosis. Femozol reduces bone density due to lower estrogen levels, and your doctor will probably recommend you to regularly check your bone density.

Femozol, pregnancy and breastfeeding

Femozol is used only in women who have gone through menopause, and is unlikely to be used during pregnancy. However, there is a small chance that postmenopausal women may become pregnant, and in such cases, you should discuss with your doctor the benefits and risks of using this medication.

Femozol and operating vehicles / machines

Given that it can cause dizziness, fatigue and drowsiness, you should not manage machines while on treatment with this drug.


The usual dose is 2.5 mg once a day or one tablet a day. It is taken regardless of meals and always at the same time of day.

The duration of treatment depends on several factors, but primarily on whether the tumor is removed or not. The therapy can take months and even years.

Femozol and side effects

Even though Femozol is an anticancer drug (which are among the most toxic drugs), it is relatively well tolerated. However, it can cause some side effects, which have a different frequency as you can see in the table below.

Rare side effects Occasional Common Very common
Loss of coordination Loss of sense of touch Dry skin Hypercholesterolemia
Chest discomfort and pain Nervousness Vaginal bleeding Hot flushes
Difficulty breathing Restlessness Malaise Fatigue
Thrombus formation, which manifests itself with the appearance of sudden pain in the hand or foot Irritability Increased or decreased appetite Increased sweating
Fever Lightheadedness Depression Joint pain
Ulcers in the mouth Stiffness of joints Alopecia Bone pain
Difficult speech Pain in breasts Hypertension /
Expressed blurred vision Urinary tract infections The decrease bone density /

If you notice symptoms of stroke, such as: paralysis, loss of feeling in any part of the body or difficulty with speech, contact a physician immediately.

Information on this website are provided for educational purposes only and are not intended for medical advice, diagnosis or treatment.

If you have any concerns or questions about your health, you should always consult with a physician or other health-care professional.

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